ASP Notes

ASP Quick Reference
ASP Examples
Introduction

Active Server Pages

ASP is a program that runs inside Internet Information Services,(IIS).

IIS comes with Windows 2000 and is a part of the Windows NT 4 option pack which can be downloaded from Microsoft.

Personal Web Server,(PWS), is a smaller, fully functional version of IIS for Windows 95 and Windows 98.
- ASP Compatibility
  
  ASP is a Microsoft technology.
  
  To run IIS you must have Windows NT 4.0 or later.
  
  To run PWS you must have Windows 95 or later.
  
  ChiliASP and InstantASP are technologies that run ASP without the Windows operating system.
- ASP Files
  
  An ASP file is the same as an HTML file.
  
  An ASP file can contain text, HTML, XML and scripts.
  
  Scripts inan ASP file are executed on teh server.
  
  An ASP file has the extension ".asp".
- Differences Between ASP and HTML Files
  
  When a browser requrests an HTML file, the server returns the file.
  
  When a browser requests an ASP file, IIS passes the request to the ASP engine. The ASP engine reads the ASP file line by line and executes the scripts in the file then, the ASP file is returned to the browser as plain HTML.
- What ASP Can Do
  
  Dynamically edit, change or add any content of a web page.
  
  Respond to user queries or data submitted from HTML forms.
  
  Access any data or database and return the results to a browser.
  
  Customize a web page to make it more useful for individual users.
  
  It is simpler and faster than CGI and Perl.
  
  It provides security since your ASP code cannot be viewed from the browser.
  
  The returned files are HTML, so they can be viewed in any browser.
  
  Clever ASP programming can minimize network traffic.
Running ASP locally
You must install PWS or IIS.
ASP Syntax

You cannot view the ASP source code by selecting "view source" in a browser, you will only see the output from the ASP file which is plain HTML. This is because the scripts are executed on the server before the result is sent back to the browser.
- The Basic Syntax Rule
  
  An ASP file normally contains HTML tags, just like an HTML file. However, an ASP file can also contain server scripts, surrounded by <% and %>.
  
  Server scripts are executed on the server and can contain any expressions, statements, procedures, or operators valid for the scripting language you use.
- The Response Object
  
  The Write method of the ASP Response Object is used to send content to the browser.
  
  The following statement sends the text "Hello World" to the browser.
```
              <%response.write("Hello World!")%>
            
```
- VBScript
  
  VBScript is the default scripting language in ASP.
```
              <html>
                <body>
                  <%response.write("Hello World")%>
                </body>
              </html>
            
```
- JavaScript
  
  To set JavaScript as the default scripting language for a particular page you must insert a language specification at the top of the page:
```
              <%@ language="javascript"%>
              <html>
                <body>
                  <%Response.Write("Hello World")%>
                </body>
              </html>
            
```
- Other Scripting Languages
  
  ASP is shipped with VBScript and JScript,(Microsoft's version of JavaScript).
  
  Other scripting languages require installation of script engines on the server.

ASP Variables

Global variables are declared outside the procedures.

Local variables are declared inside a procedure.

Examples:

1. Declaring and using a variable:

                <html>
                  <body>
                    <%
                      dim name
                      name="Donald Duck"
                      response.write("My name is: " & name)
                    %>
                  </body>
                </html>

2. Declaring and using an array:

                <html>
                  <body>
                    <%
                      Dim famname(5),i
                      famname(0) = "Jan Egil"
                      famname(1) = "Tove"
                      famname(2) = "Hege"
                      famname(3) = "Stale"
                      famname(4) = "Kai Jim"
                      famname(5) = "Borge"
                      For i = 0 to 5
                        response.write(famname(i) & "<br />")
                      Next
                    %>
                  </body>
                </html>

3. Looping through the HTML headers:

                <html>
                  <body>
                    <%
                      dim i
                      for i=1 to 6
                        response.write("<h" & i & ">Header " & i & "</h" & i & ">")
                      next
                    %>
                  </body>
                </html>

4. Time based greeting using VBScript:

                <html>
                  <body>
                    <%
                      dim h
                      h=hour(now())
                      response.write("<p>" & now())
                      response.write(" (Norwegian Time) </p>")
                      If h<12 then
                        response.write("Good Morning!")
                      else
                        response.write("Good day!")
                      end if
                    %>
                  </body>
                </html>

5. Time based greeting using JavaScript:

                <%@ language="javascript" %>
                <html>
                  <body>
                    <%
                      var d=new Date()
                      var h=d.getHours()
                      Response.Write("<p>")
                      Response.Write(d + " (Norwegian Time)")
                      Response.Write("</p>")
                      if (h<12)
                      {
                        Response.Write("Good Morning!")
                      }
                      else
                      {
                        Response.Write("Good day!")
                      }
                    %>
                  </body>
                </html>

Lifetime of Variables

A variable declared outside a procedure can be accessed and changed by any script in the ASP file.

A variable declared inside a procedure is created and destroyed every time the procedure is executed. No scripts outside the procedure can access or change it.

To declare variables accessible to more than on ASP file, declare them as session variables or application variables.
- Session Variables
  
  Session variables are used to store information about ONE single user and are available to all pages in one application. Typically information stored in session variables are name, id, and preferences.
- Application Variables
  
  Application variables are also available to all pages in one application and are used to store information about ALL users in a specific application.

ASP Procedures

Examples:

1. Calling a procedure using VBScript

                <html>
                  <head>
                    <%
                      sub vbproc(num1,num2)
                      response.write(num1*num2)
                      end sub
                    %>
                  </head>
                  <body>
                    <p>
                      You can call a procedure like this:
                    </p>
                    <p>
                      Result: <%call vbproc(3,4)%>
                    </p>
                    <p>
                      Or, like this:
                    </p>
                    <p>
                      Result: <%vbproc 3,4%>
                    </p>
                  </body>
                </html>

2. Calling a procedure using JavaScript:

                <%@ language="javascript" %>
                <html>
                  <head>
                    <%
                      function jsproc(num1,num2)
                      {
                        Response.Write(num1*num2)
                      }
                    %>
                  </head>
                  <body>
                    <p>
                      Result: <%jsproc(3,4)%>
                    </p>
                  </body>
                </html>

3. Calling both:

                <html>
                  <head>
                    <%
                      sub vbproc(num1,num2)
                      Response.Write(num1*num2)
                      end sub
                    %>
                    <script  language="javascript" runat="server">
                      function jsproc(num1,num2)
                      {
                        Response.Write(num1*num2)
                      }
                    </script>
                  </head>
                  <body>
                    <p>Result: <%call vbproc(3,4)%></p>
                    <p>Result: <%call jsproc(3,4)%></p>
                  </body>
                </html>

Differences between VBScript and JavaScript

When calling a VBScript or JavaScript procedure from an ASP file written in VBScript, you can use the "call" keyword followed by the procedure name. If a procedure requires parameters, the parameter list must be enclosed in parentheses when using the "call" keyword. If you omit the "call" keyword, the parameter list must not be enclosed in parentheses. If the procedure has no parameters the parentheses are optional.

When calling a JavaScript or VBScript procedure from an ASP file written in JavaScript, always use parentheses after the procedure name.

ASP Forms

Use the Request.QueryString and the Request.Form commands to retrieve information from forms... like user input.

Examples:

1. A form with method = "get"

                <html>
                  <body>
                    <form action="demo_reqquery.asp" method="get">
                      Your name: <input type="text" name="fname" size="20">
                      <input type="submit" value="Submit">
                    </form>
                    <%
                      dim fname
                      fname=Request.QueryString("fname")
                      If fname<>"" Then
                            Response.Write("Hello " & fname & "!<br />")
                            Response.Write("How are you today?")
                      End If
                    %>
                  </body>
                </html>

2. A form with method = "post"

                <html>
                  <body>
                    <form action="demo_simpleform.asp" method="post">
                      Your name: <input type="text" name="fname" size="20">
                      <input type="submit" value="Submit">
                    </form>
                    <%
                      dim fname
                      fname=Request.Form("fname")
                      If fname<>"" Then
                            Response.Write("Hello " & fname & "!<br />")
                            Response.Write("How are you today?")
                      End If
                    %>
                  </body>
                </html>

3. A form with radio buttons

                <html>
                  <%
                    dim cars
                    cars=Request.Form("cars")
                  %>
                  <body>
                    <form action="demo_radiob.asp" method="post">
                      <p>Please select your favorite car:</p>
                      <input type="radio" name="cars"
                      <%if cars="Volvo" then Response.Write("checked")%>
                      value="Volvo">Volvo</input>
                      <br />
                      <input type="radio" name="cars"
                      <%if cars="Saab" then Response.Write("checked")%>
                      value="Saab">Saab</input>
                      <br />
                      <input type="radio" name="cars"
                      <%if cars="BMW" then Response.Write("checked")%>
                      value="BMW">BMW</input>
                      <br /><br />
                      <input type="submit" value="Submit" />
                    </form>
                    <%
                      if cars<>"" then
                         Response.Write("<p>Your favorite car is: " & cars & "</p>")
                      end if
                    %>
                  </body>
                </html>

User Input

The request object may be used to retrieve user information from forms:

                <form method="get" action="simpleform.asp">
                  First Name: <input type="text" name="fname">
                  <br />
                  Last Name: <input type="text" name="lname">
                  <br /><br />
                  <input type="submit" value="Submit">
                </form>

User input can be retrieved with Request.QueryString or Request.Form.

Request.QueryString
The Request.QuerySring command is used to collect values in a form with method="get". Information sent from a form with the GET method is visible to everyone, and is displayed in the browser's address bar and has limits on the amount of information to send.

If a user typed "Bill" and "Gates" in the form example above, the URL sent to the server would look like this:
```
                http://www.w3schools.com/simpleform.asp?fname=Bill&lname=Gates
              
```
Assume that the ASP file "simpleform.asp" contains the following script:
```
                <body>
                  Welcome
                  <%
                    response.write(request.querystring("fname"))
                    response.write(" " & request.querystring("lname"))
                  %>
                </body>
              
```
The browser would display the following in the body of the document:
```
                Welcome Bill Gates
              
```
Request.Form
The Request.Form command is used to collect values in a form with method="post". Information sent from a form with the POST method is invisible to others and has no limits on the amount of information to send.

If a user typed "Bill" and "Gates" in the form example above, the URL sent to the server would look like this:
```
                http://www.w3schools.com/simpleform.asp
              
```
Assume that the ASP file "simpleform.asp" contains the following script:
```
                <body>
                  Welcome
                  <%
                    response.write(request.form("fname"))
                    response.write(" " & request.form("lname"))
                  %>
                </body>
              
```
The browser would display the following in the body of the document:
```
                Welcome Bill Gates
              
```
Form Validation

User input should be validated on the browser whenever possible, by client scripts. Browser validation is faster and you reduce the server load.

Use server side validation if the user input will be inserted into a database. A good way to validate a form on the server is to post the form to itself instead of jumping to another page. The user will then get the error messages on the same page as the form.

ASP Cookies

Cookies are often used to identify users

Example: The Welcome Cookie.

            <%
              dim numvisits
              response.cookies("NumVisits").Expires=date+365
              numvisits=request.cookies("NumVisits")
            %>
            <html>
              <body>
                <%
                  if numvisits="" then response.cookies("NumVisits")=1
                %>
                  Welcome! This is the first time you are visiting this Web page.
                <%
                  else
                     response.cookies("NumVisits")=numvisits+1
                     response.write("You have visited this ")
                     response.write("Web page " & numvisits)
                     if numvisits=1 then
                       response.write " time before!"
                     else
                       response.write " times before!"
                     end if
                  end if
                %>
              </body>
            </html>

A cookie is a small file that the server writes to the user's computer. Each time the same computer requests for a page with a browser, it will send the cookie too. With ASP you can create and retrieve cookie values.

How to Create a Cookie

The "Response.Cookies" command is used to create cookies.

The "Response.Cookies" command must appear BEFORE the <html> tag.

Example: create a cookie named "firstname" and assign it the value "Alex":

                <%Response.Cookies("firstname")="Alex"%>

It is also possible to assign properties like expiration date to a cookie.

                <%
                  Response.Cookies("fistname")="Alex"
                  Response.Cookies("firstname").Expires=#May 10,2002#
                %>

How to retrieve a Cookie Value

The "Requet.Cookies" command is used to retrieve a cookie value.

Example:Retrieve the value of the cookie named "firstname" and display it on a page.

                <%
                  fname=Request.Cookies("firstname")
                  response.write("Firstname=" & fname)
                %>

Output would look like this:

                Firstname=Alex

Cookies with Keys

If a cookie contains a collection of values it is a cookie with keys.

Example: create a cookie collection named "user".

                <%
                  Response.Cookies("user")("firstname")="John"
                  Response.Cookies("user")("lastname")="Smith"
                  Response.Cookies("user")("country")="Norway"
                  Response.Cookies("user")("age")="25"
                %>

Reading All Cookies

Example: Code to send cookies

                <%
                  Response.Cookies("firstname")="Alex"
                  Response.Cookies("user")("firstname")="John"
                  Response.Cookies("user")("lastname")="Smith"
                  Response.Cookies("user")("country")="Norway"
                  Response.Cookies("user")("age")="25"
                %>

Assuming that the server has sent all the above cookies to a user.

Example: Code to read all the cookies sent to a user.

                <html>
                  <body>
                    <%
                      dim x,yfor each x in Request.Cookies
                        response.write("<p>")
                        if Request.Cookies(x).HasKeys then
                          for each y in Request.Cookies(x)
                            response.write(x & ":" & y & "=" & Request.Cookies(x)(y))
                            response.write("<br />")
                          next
                        else
                          Response.Write(x & "=" & Request.Cookies(x) & "<br />")
                        end if
                        response.write "</p>"
                      next
                    %>
                  </body>
                </html>

Output:

                firstname=Alex
                user:firstname=John
                user:lastname=Smith
                user:country=Norway
                user:age=25

Passing Information on Browsers That Don't Support Cookies

Add Parameters to a URL

Example:

                    <a href="welcome.asp?fname=John&lname=Smith">
                      Go to Welcome Page
                    </a>

Retrieve the values in the "welcome.asp" file like this:

                    <%
                      fname=Request.querystring("fname")
                      lname=Request.querystring("lname")
                      response.write("<p>Hello " & fname & " " & lname & "!</p>")
                      response.write("<p>Welcome to my Web site!</p>")
                    %>

Or Use a Form

Example:

                    <form method="post" action="welcome.asp">
                      First Name: <input type="text" name="fname" value="">
                      Last Name:  <input type="text" name="lname" value="">
                      <input type="submit" value="Submit">
                    </form>

And Retrieve the values in the "welcome.asp" file like this:

                    <%
                      fname=Request.form("fname")
                      lname=Request.form("lname")
                      response.write("<p>Hello " & fname & " " & lname & "!</p>")
                      response.write("<p>Welcome to my Web site!</p>")
                    %>

ASP Session Object
When you are working with an application, you open it, do some changes and then close it. This is musck like a session. The computer knows who you are. It knows when you start the application and when you end. But on the internet the server doesn't know who you are or what you are doing because the HTTP address doesn't maintain state.

ASP therefore creates a unizue cookie foe earch user. The cookie is sent to the client and it contains information that identifies the user. This interface is called the Session Object.

The session object is used to store information about, or change settings for a user session. Variables stored in the session object hold information about one single user and are available to all pages in one application. Common information stored in session variables are name, id, and preferences. The server creates a new session ojbect for each new user and destroys the session object when the session expires.

A Session Starts When:

* A user requests an ASP file and the Global.asa file includes a
Session_OnStart procedure.

* A value is stored in a Session variable.

* A user requests an ASP file and the Global.asa file uses the <object> tag
to instantiate an object with session scope.
A Session Ends When:
A user has not requested or refreshed a page in the application for a specified period of time. By default, this is 20 minutes.

If you want to set a timeout interval that is shorter or longer than the default you can seet the Timeout property.

Example:
```
                <%
                  Session.Timeout=5
                %>
              
```
To end a session immediately, you can use the Abandon method:
```
                <%
                  Session.Abandon
                %>
              
```
The main problem with sessions is WHEN they should end.
We do not know if the user's last request was the final one or not so we do not know how long we should keep the session alive.
Waiting too long uses up resources on the server, but if the session is deleted too soon you risk the user returning after the server has deleted all the information.

IF you are using session variables, store small amounts of data in them.
- Storing and Retrieving Session Variables
  The most important thing about the Session Object is that you can store variables in it.
  
  Example: <% Session("username")="Donald Duck" Session("age")=50 %>
  When the value is stored in a session variable it can be reached from any page in the ASP application.
  
  Example:
```
                Welcome <%Response.Write(Session("username"))%>
              
```
  You can also store user preferences in the session object and then use them to determine what page to return to the user.
  
  Example:
```
                <% If Session("screenres")="low" Then%>
                  This is the text version of the page
                <%Else%>
                  This is the multimedia version of the page
                <%End If%>
              
```
- Removing Session Variables
  The contents collection contains all session variables and they can be removed with the Remove method.
  
  Example:
```
                <%
                  If Session.Contents("age") < 18 then
                    Session.Contents.Remove("sale")
                  End If
                %>
              
```
  Example: Remove all variables in a session, using the RemoveAll method
```
                <%Session.Contents.RemoveAll()%>
              
```
- Looping Through the Contents Collection
  The Contents collection contains all session variables and you can loop through them to see what's stored in them.
  
  Example:
```
                <%
                  Session("username")="Donald Duck"
                  Session("age")=50dim i
                  For Each i in Session.Contents
                    Response.Write(i & "<br />")
                  Next
                %>
              
```
  Result:
```
                username
                age
              
```
  Use the Count property to determine the number of items in the Contents collection.
  
  Example:
```
                <%
                  dim i
                  dim j
                  j=Session.Contents.Count
                  Response.Write("Session variables: " & j)
                  For i=1 to j
                    Response.Write(Session.Contents(i) & "<br />")
                  Next
                %>
              
```
  Result:
```
                Session variables: 2
                Donald Duck
                50
              
```
- Looping Through The StaticObjects Collection
  Loop through the StaticObjects collection to see the values of all objects stored inside the Session Object.
  
  Example:
```
                <%
                  dim i
                  For Each i in Session.StaticObjects
                    Response.Write(i & "<br />")
                  Next
                %>
              
```
ASP Application Object

An application on the web may be a group of ASP files. The ASP files work together to perform some function. The application object in ASP is used to tie these files together.

The Application object is used to store and access variables from any page just like the Session object. But All users share one Application object while Each user has their own Session object.

The Application object should hold information that will be used by many pages in the application, like databse connection information. This means that you can access the information from any page. It also means that you can change the information in one place and the changes will automatically be reflected on all pages.
- Storing and Retrieving Application Values
  Application variables can be accessed and changed by any page in the application.
  
  Example: Creating Application variables in "Global.asa":
```
                <script language="vbscript" runat="server">
                  Sub Application_OnStart
                    application("vartime")=""
                    application("users")=1
                  End Sub
                </script>
              
```
  In the example above we have created 2 Application variables: "vartime" and "users".
  
  You can access the value of an Application variable like this:
```
                There are <%Response.Write(Application("users"))%> active connections.
              
```
- Looping Through the Contents Collection
  The Contents collection contains all application variables. Loop through the Contents collection to see what's stored in it.
```
                <%
                  dim i
                  For Each i in Application.Contents
                    Response.Write(i & "<br />")
                  Next
                %>
              
```
  Use the count property to determine the number of items in the Contents collection:
```
                <%
                  dim i
                  dim j
                  j = Application.Contents.Count
                  For i = 1 to j
                    Response.Write(Application.Contents) & "<br />")
                  Next
                %>
              
```
- Looping Through the StaticObjects Collection
  Loop through the StaticObjects collection to see the valuea of all objects in the Application object:
```
                <%
                  dim i
                  For Each i in Application.StaticObjects
                    Response.Write(i & "<br />")
                  Next
                %>
              
```
- Lock and Unlock
  You can lock an application with the "Lock" method. When an applicationis locked the user cannot change the Application variables, other than the one currently accessing it. You can unlock an application with the "Unlock" method which removes the lock from the Application variable:
```
                <%
                  Application.Lock
                   'do some application object operations
                  Application.Unlock
                %>
              
```
ASP #include

The #include directive is used to create functions, headers, foorters or elements that will be reused on multiple pages.
- The #include Directive
  
  You can insert to content of one ASP file into another ASP file before the server executes it with the #include directive.
- How to Use the #include Directive
  Example:
```
                <html>
                  <body>
                    <h3>Words of Wisdom:</h3>
                    <p></p>
                    <h3>The time is:</h3>
                    <p></p>
                  </body>
                </html>
              
```
  Here is the "wisdom.inc" file
```
                "One should never increase, beyond what is necessary,
                 the number of entities required to explain anything."
              
```
  Here is the "time.inc" file:
```
                <%Response.Write(Time)%>
              
```
  And if you look at the source code with a browser, it will look like this:
```
                <html>
                  <body>
                    <h3>Words of Wisdom:</h3>
                    <p>"One should never increase, beyond what is necessary,
                    the number of entities required to explain anything."</p>
                    <h3>The time is:</h3>
                    <p>11:33:42 AM</p>
                  </body>
                </html>
              
```
- Syntax for INcluding Files
  To include a file in an ASP page, place the #include directive inside comments.
```
                
                Or
                
              
```
- The Virtual Keyword
  User the virtual keyword to indicate a virtual path.
  
  Example: If a file named "header.inc" resides in a virtual directory named /html
```
                
              
```
- The File Keyword
  Use the file keyword to indicate a relative path. A relative path begins with the directory that contains the including file.
  
  Example: If you have a file in the html directory and the file "header.inc" is in html\headers.
```
                
              
```
  Use the syntax ..\ to include a file from a higher level directory.
- Tips and Notes
  In the sections above we have used the file extension ".inc" for included files. Notice that if a user tries to browse an INC file diretly, it's content will be displayed. If your included file contains confidential information or information you do not want any users to see, it is better to use an ".asp" extension. The source code in the ASP file will not be visible after the interpretation. An included file can also include other files and one ASP file can include the same file more than once.
  
  Included files are processed and inserted before the scripts are executed.
  
  The following will not work because ASP executes the #include directive before it assigns a value to the variable.
```
                <% fname="header.inc"%>
                
              
```
  You cannot open or close a script delimiter in an INC file.
  
  The following will not work.
```
                <%
                  For i = 1 To n
                    
                  Next
                %>
              
```
  But this will work.
```
                <% For i = 1 to n %>
                  
                <% Next %>
            
```

ASP Global.asa

The Global.asa file is an optional file that can contain declarations of objects, variables, and methods that can be accessed by every page in an ASP application. All valid browser scripts can be used within Global.asa.

The Global.asa file can only contain the following.

* Application events.

* Session events.

* <object> declarations.

* TypeLibrary declarations.

* the #include directive.

Note the Global.asa file must be stored in the root directory of the ASP application and each application can have only 1 Global.asa file.

Events in Global.asa
In the Global.asa you can tell the application and session objects what to do when the application/session starts and snds. The code for this is placed in event handlers. The Global.asa file can contain 4 types of events.
1. Application_OnStart
  
  This event occurs when the first user calls the first page from the ASP application. This event occurs after the web server is restarted or after the Global.asa file is edited. The "Session_OnStart event occurs immediately after this event.
2. Session_OnStart
  
  This event occurs every time a new user requests their first page in the ASP application.
3. Session_OnEnd
  
  This event occurs every time a user ends a session. A user ends a session after a page has not been requested by the user for a specified period of time, which is, by default 20 minutes.
4. Application_OnEnd
  
  This event occurs after the last user has ended the session. Typically, this event occurs when a web server stops. This procedure is used to clean up settings after the application stops, like deleting records or writing information to text files.
A Global.asa file could looks something like this:
```
                <script language="vbscript" runat="server">
                  sub Application_OnStart
                    ''''some code
                  end sub
                  sub Application_OnEnd
                    ''''some code
                  end sub
                  sub Session_OnStart
                    ''''some code
                  end sub
                  sub Session_OnEnd
                  ''''some code
                  end sub
                </script>
              
```
You cannot use the ASP script delimiters <% or %> to insert scripts into the Global.asa file. You have to put the subroutines inside HTML <script> tags.

It is possible to create objects with session or application scope in the Global.asa by using the <object> tag.

The <object> tag should be outside the <script> tag.

Syntax:

                <object runat="server" scope="scope" id="id" (progid="prodID"|classid="classID")>
                  ...
                </object>

Parameters:

Parameter	Description
scope	Sets the scope of the object either Session or Application
id	Specifies a unique id for the object
ProgID	An id associated with a class id. format = [Vendor.]Component[.Version]
ClassID	Specifies a unique id for a COM class object Either ProgID or ClassID must be specified

Examples:

1. Create an object of session scope named "MyAd" using the ProgID
parameter:

                    <object runat="server" scope="session" id="MyAd" progid="MSWC.AdRotator">
                    </object>

2. Create an object of application scope named "MyConnection" using the
ClassID parameter:

                    <object runat="server" scope="application" id = "MyConnection"
                    classid="Clsid::8AD3067A-B3FC-11CF-A560-00A0C9081C21">
                    </object>

The objects declared in the Global.asa file can be used by any script in the application:

                    GLOBAL.ASA:

                    <object runat="server" scope="session" id="MyAd" progid="MSWC.AdRotator">
                    </object>
                    You could reference the object "MyAd" from any page in the ASP application:

                    SOME .ASP FILE:

                    <%=MyAd.GetAdvertisement("/banners/adrot.txt")%>

TypeLibrary Declarations

A TypeLibrary is a container for the contents of a DLL file corresponding to a COM object. By including a call to the TypeLibrary in the Global.asa file, the constants of the COM object can be accessed, and errors can be better reported by the ASP code. If your web application relies on COM objects that have declared data types in the type libraries, you can declare the type librarires in the Global.asa file.

Syntax:

                <!--METADATA
                  TYPE="TypeLib"
                  file="filename"
                  uuid="typelibraryuuid"
                  version="versionnumber"
                  lcid="localeid"
                -->

Parameters:

Parameter	Description
file	Specifies an absolute path to a type library Either the file or the uuid parameter is required
uuid	Specifies a unique identifier for the type library Either the file or the uuid parameter is required
version	Optional. Used for selecting version If the requested version isn't found the most recent version is used.
localeid	Optional. The locale identifier to be used for the type library

Error Values:

The server can return one of the following error messages.

Error Code	Description
ASP 0222	Invalid type library specification.
ASP 0223	Type library not found.
ASP 0224	Type library cannot be loaded.
ASP 0225	Type library cannot be wrapped.

METADATA tags can appear anywhere in the Global.asa file, both inside and outside the <script> tags. However, it is recommended that METADATA tags appear near the top of the Global.asa file.

Restrictions

Restrictions on what you can include in the Global.asa file:

* You cannot display text that is written in the Global.asa file.
  This file cannot display information.

* You can only use Server and Application objects in the
  Application_OnStart and the Application_OnEnd subroutines.

* In the Session_OnEnd subroutine, you can use Server,
  Applcation and Session objects.

* In the Session_OnStart subroutine you can use any built in object.

How to Use the Subroutines

Global.asa is often used to initialize variables.

The example below shows how to detect the exact time a visitor first arrives on a page. The time is stored in a Session variable named "started", and the value of "started" can be accessed from any ASP page in the application:

                <script language="vbscript" runat="server">
                  sub Session_OnStart
                    Session("started")=now()
                  end sub
                </script>

Global.asa can also be used to control page access.

The following example shows how to redirect every new visitor to another page called "newpage.asp":

                <script language="vbscript" runat="server">
                  sub Session_OnStart
                    Response.Redirect("newpage.asp")
                  end sub
                </script>

And you can include functions in the Global.asa file.

In the example below the Application_OnStart subroutine occurs when the web server starts. Then the Application_OnStart subroutine calls another subroutine named "getcustomers". The "getcustomers" subroutine opens a database and retrieves a record set from the "customers" table. The recordset is assigned to an array where it can be accessed from any ASP page without querying the database:

                <script language="vbscript" runat="server">
                  sub Application_OnStart
                    getcustomers
                  end sub
                  sub getcustomers
                    set conn=Server.CreateObject("ADODB.Connection")
                    conn.Provider="Microsoft.Jet.OLEDB.4.0"
                    conn.Open "c:/webdata/northwind.mdb"
                    set rs=conn.execute("select name from customers")
                    Application("customers")=rs.GetRows
                    rs.Close
                    conn.Close
                  end sub
                </script>

Global.asa Example:

In this example we will create a Global.asa file that counts the number of current visitors.

* The Application_OnStart sets the Application variable "visitors" to 0
when the server starts.

* The Session_OnStart subroutine adds one to the variable "visitors"
everytime a new visitor arrives.

* The Session_OnEnd subroutine subtracts one from "visitors" each time
the subroutine is triggered:

                <script language="vbscript" runat="server">
                  Sub Application_OnStart
                    Application("visitors")=0
                  End Sub
                  Sub Session_OnStart
                    Application.Lock
                    Application("visitors")=Application("visitors")+1
                    Application.UnLock
                  End Sub
                  Sub Session_OnEnd
                    Application.Lock
                    Application("visitors")=Application("visitors")-1
                    Application.UnLock
                  End Sub
                </script>

To display the number of current visitors in the ASP file:

                <html>
                  <head>
                  </head>
                  <body>
                    <p>
                      There are <%response.write(Application("visitors"))%>
                      online now!
                    </p>
                  </body>
                </html>

ASP Response Object

The ASP Response object is used to send output to the user from the server.

Collections, Properties and Methods of the ASP Response Object

Collections

Collection	Description
Cookies	Sets a cookie value. If the cookie doesn't exist, it will be created and take the specified value

Properties

Property	Description
Buffer	Specifies whether to buffer the page output
CacheControl	Sets whether a proxy server can cache the ASP output
Charset	Appends the name of a character-set to the content-type header in the Response object
ContentType	Sets the HTTP content type for the Response object
Expires	Sets how long a page will be cached on a browser
ExpiresAbsolute	Sets a date and time a cached page will expire
IsClientConnected	Indicates if the client has disconnected
Pics	Appends a value to the PICS label response header
Status	Specifies the value of the status line returned by the server

Methods

Method	Description
AddHeader	Adds a new HTTP header and a value to the HTTP response
AppendToLog	Adds a string to the end of the server log
BinaryWrite	Writes data directly to the output without any character conversion
Clear	Clears any buffered HTML output
End	Stops processing a script and returns the current result
Flush	Sends buffered HTML output immediately
Redirect	Redirects the user to a different URL
Write	Writes a specified string to the output

Examples:

Write text with ASP.

                <html>
                  <body>
                    <%
                      response.write("Hello World!")
                    %>
                  </body>
                </html>

Format text with HTML tags using ASP.

                <html>
                  <body>
                    <%
                      response.write("<h2>
                                        You can use HTML tags to format the text!
                                      </h2>")
                    %>
                    <%
                      response.write("<p style='color:#0000ff'>
                                        This text is styled with the style attribute!
                                      </p>")
                    %>
                  </body>
                </html>

Redirect the user to a different URL.

                <%
                  if Request.Form("select")<>"" then
                    Response.Redirect(Request.Form("select"))
                  end if
                %>
                <html>
                  <body>
                    <form action="demo_redirect.asp" method="post">
                      <input type="radio" name="select" value="demo_server.asp">
                        Server Example<br>
                      <input type="radio" name="select" value="demo_text.asp">
                        Text Example<br><br>
                      <input type="submit" value="Go!">
                    </form>
                  </body>
                </html>

Show a random link:

                <html>
                  <body>
                    <%
                      randomize()
                      r=rnd()
                      if r>0.5 then
                        response.write("<a href='http://www.w3schools.com'>
                                          W3Schools.com!
                                        </a>")
                      else
                        response.write("<a href='http://www.refsnesdata.no'>
                                          Refsnesdata.no!
                                        </a>")
                      end if
                    %>
                    <p>
                      This example demonstrates a link, each time you load the page,
                      it will display one of two links: W3Schools.com! OR Refsnesdata.no!
                      There is a 50% chance for each of them.
                    </p>
                  </body>
                </html>

Flushing the buffer:

                <%
                  Response.Buffer=true
                %>
                <html>
                  <body>
                    <p>
                      This text will be sent to your browser when my response buffer
                      is flushed.
                    </p>
                    <%
                      Response.Flush
                    %>
                  </body>
                </html>

Clearing the buffer:

                <%
                  Response.Buffer=true
                %>
                <html>
                  <body>
                    <p>This is some text I want to send to the user.</p>
                    <p>No, I changed my mind. I want to clear the text.</p>
                    <%
                      Response.Clear
                    %>
                  </body>
                </html>

End a script in mid-processing and return the result:

                <html>
                  <body>
                    <p>I am writing some text. This text will never be<br>
                      <%
                        Response.End
                      %>
                      finished! It's too late to write more!
                    </p>
                  </body>
                </html>

Set how many minutes a page will be cached:

                <%Response.Expires=-1%>
                <html>
                  <body>
                    <p>This page will be refreshed with each access!</p>
                  </body>
                </html>

Set a date/time when a page will expire

                <%
                  Response.ExpiresAbsolute=#May 05,2001 05:30:30#
                %>
                <html>
                  <body>
                    <p>This page will expire on May 05, 2001 05:30:30!</p>
                  </body>
                </html>

Check if user is still connected to the server:

                <html>
                  <body>
                    <%
                      If Response.IsClientConnected=true then
                        Response.Write("The user is still connected!")
                      else
                        Response.Write("The user is not connected!")
                      end if
                    %>
                  </body>
                </html>

Set the type of content:

                <%
                  Response.ContentType="text/html"
                %>
                <html>
                  <body>
                    <p>This is some text</p>
                  </body>
                </html>

Set the name of the character set:

                <%
                  Response.Charset="ISO8859-1"
                %>
                <html>
                  <body>
                    <p>This is some text</p>
                  </body>
                </html>

ASP Request Object

The ASP request object is used to get information from the user.

Collections, Properties and Methods of the ASP Request Object

Collections

Collection	Description
ClientCertificate	Contains all field values in the clientcertificate
Cookies	Contains all cookie values sent in an HTTP request
Form	Contains all the form (input) values from a form that uses the post method
QueryString	Contains all the variable values in an HTTP query string
ServerVariables	Contains all the server variable values

Properties

Property	Description
TotalBytes	Returns the total number of bytes the client sent in the body of the request

Methods

Method	Description
BinaryRead	Retrieves the data sent to the server from the client as part of a post request and stores it in a safe array

Examples:

QueryString Collection Examples:

Send query information when a user clicks on a link

                    <html>
                      <body>
                        <a href="demo_simplequerystring.asp?color=green">Example</a>
                        <%
                          Response.Write(Request.QueryString)
                        %>
                      </body>
                    </html>

A QueryString collection in it's simplest use

                    <html>
                      <body>
                        <form action="demo_simplereqquery.asp" method="get">
                          First name: <input type="text" name="fname"><br>
                          Last name: <input type="text" name="lname"><br>
                          <input type="submit" value="Submit">
                        </form>
                        <%
                          Response.Write(Request.QueryString)
                        %>
                      </body>
                    </html>

How to use information from forms

                    <html>
                      <body>
                        <form action="demo_reqquery.asp" method="get">
                          Your name: <input type="text" name="fname" size="20">
                          <input type="submit" value="Submit">
                        </form>
                        <%
                          dim fname
                          fname=Request.QueryString("fname")
                          If fname<>"" Then
                            Response.Write("Hello " & fname & "!<br />")
                            Response.Write("How are you today?")
                          End If
                        %>
                      </body>
                    </html>

More information from a form

                    <html>
                      <body>
                        <%
                          If Request.QueryString<>"" Then
                            If Request.QueryString("name")<>", " Then
                              name1=Request.QueryString("name")(1)
                              name2=Request.QueryString("name")(2)
                            end if
                          end if
                        %>
                        <form action="demo_reqquery2.asp" method="get">
                          First name:
                          <input type="text" name="name" value="<%=name1%>">
                          <br>
                          Last name:
                          <input type="text" name="name" value="<%=name2%>">
                          <br>
                          <input type="submit" value="Submit">
                        </form>
                        <hr>
                        <%
                          If Request.QueryString<>"" Then
                            Response.Write("<p>")
                            Response.Write("The information received from the form was:")
                            Response.Write("</p><p>")
                            Response.Write("name=" & Request.QueryString("name"))
                            Response.Write("</p><p>")
                            Response.Write("The name property's count is: ")
                            Response.Write(Request.QueryString("name").Count)
                            Response.Write("</p><p>")
                            Response.Write("First name=" & name1)
                            Response.Write("</p><p>")
                            Response.Write("Last name=" & name2)
                            Response.Write("</p>")
                          end if
                        %>
                      </body>
                    </html>

Form Collection Examples:

A form collection in it's simplest use

                    <html>
                      <body>
                        <form action="demo_simpleform1.asp" method="post">
                          First name:
                          <input type="text" name="fname" value="Donald">
                          <br>
                          Last name:
                          <input type="text" name="lname" value="Duck">
                          <br>
                          <input type="submit" value="Submit">
                        </form>
                        <%
                          Response.Write(Request.Form)
                        %>
                      </body>
                    </html>

How to use information from forms

                    <html>
                      <body>
                        <form action="demo_simpleform.asp" method="post">
                          Your name: <input type="text" name="fname" size="20">
                          <input type="submit" value="Submit">
                        </form>
                        <%
                          dim fname
                          fname=Request.Form("fname")
                          If fname<>"" Then
                            Response.Write("Hello " & fname & "!<br />")
                            Response.Write("How are you today?")
                          End If
                        %>
                      </body>
                    </html>

More information from a form</dd>

                    <html>
                      <body>
                        <form action="demo_form2.asp" method="post">
                          First name:
                          <input type="text" name="name" value="Donald">
                          <br>
                          Last name:
                          <input type="text" name="name" value="Duck">
                          <br>
                          <input type="submit" value="Submit">
                        </form>
                        <hr>
                        <p>The information received from the form above was:</p>
                        <%
                          If Request.Form("name")<>"" Then
                            Response.Write("<p>")
                            Response.Write("name=" & Request.Form("name"))
                            Response.Write("</p><p>")
                            Response.Write("The name property's count is: ")
                            Response.Write(Request.Form("name").Count)
                            Response.Write("</p><p>")
                            Response.Write("First name=" & Request.Form("name")(1))
                            Response.Write("</p><p>")
                            Response.Write("Last name=" & Request.Form("name")(2))
                            Response.Write("</p>")
                          End if
                        %>
                      </body>
                    </html>

A form with radio buttons

                    <html>
                      <%
                        dim cars
                        cars=Request.Form("cars")
                      %>
                      <body>
                        <form action="demo_radiob.asp" method="post">
                          <p>Please select your favorite car:</p>
                          <input type="radio" name="cars"
                          <%if cars="Volvo" then Response.Write("checked")%>
                          value="Volvo">Volvo</input>
                          <br />
                          <input type="radio" name="cars"
                          <%if cars="Saab" then Response.Write("checked")%>
                          value="Saab">Saab</input>
                          <br />
                          <input type="radio" name="cars"
                          <%if cars="BMW" then Response.Write("checked")%>
                          value="BMW">BMW</input>
                          <br /><br />
                          <input type="submit" value="Submit" />
                        </form>
                        <%
                          if cars<>"" then
                            Response.Write("<p>Your favorite car is: " & cars & "</p>")
                          end if
                        %>
                      </body>
                    </html>

A form with checkboxes

                    <html>
                      <body>
                        <%
                          fruits=Request.Form("fruits")
                        %>
                        <form action="demo_checkboxes.asp" method="post">
                          <p>Which of these fruits do you prefer:</p>
                          <input type="checkbox" name="fruits" value="Apples"
                          <%if instr(fruits,"Apple") then Response.Write("checked")%>>
                          Apple
                          <br>
                          <input type="checkbox" name="fruits" value="Oranges"
                          <%if instr(fruits,"Oranges") then Response.Write("checked")%>>
                          Orange
                          <br>
                          <input type="checkbox" name="fruits" value="Bananas"
                          <%if instr(fruits,"Banana") then Response.Write("checked")%>>
                          Banana
                          <br>
                          <input type="submit" value="Submit">
                        </form>
                        <%
                          if fruits<>"" then%>
                            <p>You like: <%Response.Write(fruits)%></p>
                          <%end if
                        %>
                      </body>
                    </html>

Other Examples:

Get the server variables

                    <html>
                      <body>
                        <p>
                          <b>You are browsing this site with:</b>
                          <%Response.Write(Request.ServerVariables("http_user_agent"))%>
                        </p>
                        <p>
                          <b>Your IP address is:</b>
                          <%Response.Write(Request.ServerVariables("remote_addr"))%>
                        </p>
                        <p>
                          <b>The DNS lookup of the IP address is:</b>
                          <%Response.Write(Request.ServerVariables("remote_host"))%>
                        </p>
                        <p>
                          <b>The method used to call the page:</b>
                          <%Response.Write(Request.ServerVariables("request_method"))%>
                        </p>
                        <p>
                          <b>The server's domain name:</b>
                          <%Response.Write(Request.ServerVariables("server_name"))%>
                        </p>
                        <p>
                          <b>The server's port:</b>
                          <%Response.Write(Request.ServerVariables("server_port"))%>
                        </p>
                        <p>
                          <b>The server's software:</b>
                          <%Response.Write(Request.ServerVariables("server_software"))%>
                        </p>
                      </body>
                    </html>

Create a welcome cookie

                    <%
                      dim numvisits
                      response.cookies("NumVisits").Expires=date+365
                      numvisits=request.cookies("NumVisits")
                    %>
                    <html>
                      <body>
                        <%
                          if numvisits="" then
                            response.cookies("NumVisits")=1
                        %>
                          Welcome! This is your first time visiting this Web page.
                        <%
                          else
                            response.cookies("NumVisits")=numvisits+1
                            response.write("You have visited this ")
                            response.write("Web page " & numvisits)
                            if numvisits=1 then
                              response.write " time before!"
                            else
                              response.write " times before!"
                            end if
                          end if
                        %>
                      </body>
                    </html>

Find the total number of bytes the user sent

                    <html>
                      <body>
                        <form action="demo_totalbytes.asp" method="post">
                          Please type something:
                          <input type="text" name="txt"><br><br>
                          <input type="submit" value="Submit">
                        </form>
                        <%
                          If Request.Form("txt")<>"" Then
                            Response.Write("You submitted: ")
                            Response.Write(Request.Form)
                            Response.Write("<br><br>")
                            Response.Write("Total bytes: ")
                            Response.Write(Request.Totalbytes)
                          End If
                        %>
                      </body>
                    </html>

ASP Application Object

An applciation on the web may be a group of ASP files. The ASP files work together to perform some purpose. The application object in ASP is used to tie these files together.

The application object is used to store and access variables from any page just like the session object. But ALL users share one application object and there is only one session object for EACH user.

The application object should hold information that will be used by many pages in the application; like database connection information. This means that you can access the information from any page. It also means that you can change the information in one place and the changes will automatically be reflected on all pages.

Collections

Collection	Description
Contents	Contains all the items appended to the application through a script command
StaticObjects	Contains all the objets appended to the application with teh HTML <object> tag.

Methods

Method	Description
Contents.Remove	Deletes an item from the Contents collection
Contents.RemoveAll()	Deletes all items from the Contents collection
Lock	Prevents other users from modifying the variables in the application object
Unlock	Enables other users to modifythe variables in the application object after a lock

Events

Event	Description
Application_OnEnd	Occurs when all user sessions are over and the application ends
Application_OnStart	Occurs before the first new session is created When the application object is first referenced

ASP Session Object

The session object is used to store information about, or change settings for a user session. Variables stored in the session object hold information about one single user and are available to all pages in one application.

ASP creates a unique cookie for each user. The cookie is sent to the client and it contains information that identifies teh user. This interface is called the session object.

Common information stored in the session variables are name, id and preferences. The server creates a new session object for each new user and destroys the session object when the session expires.

Collections

Collection	Description
Contents	Contains all the items appended to the session through a script command
StaticObjects	Contains all the objects appended to the session using the HTML <object> tag.

Properties

Property	Description
CodePage	Specifies the character set that will be used when displaying dynamic content.
LCID	Sets or returns an integer that specifies a location or region. Contents like date, time and currency will be displayed according to that location or region.
SessionID	Returns a unique id for each user. The id is generated by the server.
Timeout	Sets or returns the timeout period in minutes for the Session object in this application.

Methods

Method	Description
Abandon	Destroys a user session
Contens.Remove	Delets an item from the Contents collection.
Contents.RemoveAll()	Delets all items from the Contents collection

Events

Event	Description
Session_OnEnd	Occurs when the session ends
Session_OnStart	Occurs when the session starts

Examples:

Set and return the LCID

                <html>
                  <body>
                    <%
                      response.write("<p>")
                      response.write("The default LCID for this page is: " & Session.LCID & "<br />")
                      response.write("The Date format for the above LCID is: " & date() & "<br />")
                      response.write("The Currency format for the above LCID is: " & FormatCurrency(350))
                      response.write("</p>")
                      Session.LCID=1036
                      response.write("<p>")
                      response.write("The LCID is now changed to: " & Session.LCID & "<br />")
                      response.write("The Date format for the above LCID is: " & date() & "<br />")
                      response.write("The Currency format for the above LCID is: " & FormatCurrency(350))
                      response.write("</p>")
                      Session.LCID = 3079
                      response.write("<p>")
                      response.write("The LCID is now changed to: " & Session.LCID & "<br />")
                      response.write("The Date format for the above LCID is: " & date() & "<br />")
                      response.write("The Currency format for the above LCID is: " & FormatCurrency(350))
                      response.write("</p>")
                      Session.LCID = 2057
                      response.write("<p>")
                      response.write("The LCID is now changed to: " & Session.LCID & "<br />")
                      response.write("The Date format for the above LCID is: " & date() & "<br />")
                      response.write("The Currency format for the above LCID is: " & FormatCurrency(350))
                      response.write("</p>")
                    %>
                  </body>
                </html>

Return the SessionID

                <html>
                  <body>
                    <%
                      Response.Write(Session.SessionID)
                    %>
                  </body>
                </html>

A session's timeout

                <html>
                  <body>
                    <%
                      response.write("<p>")
                      response.write("Default Timeout is: " & Session.Timeout & " minutes.")
                      response.write("</p>")
                      Session.Timeout=30
                      response.write("<p>")
                      response.write("Timeout is now: " & Session.Timeout & " minutes.")
                      response.write("</p>")
                    %>
                  </body>
                </html>

ASP Server Object

The ASP Server object is used to access properties and methods on the server.

Properties

Property	Description
ScriptTimeout	Sets or returns the maximum number of seconds a script can run before it is terminated

Methods

Method	Description
CreateObject	Creates an instance of an object.
Execute	Executes an ASP file from inside an ASP file
GetLastError()	Returns an ASPError object that describes the error condition that occurred
HTMLEncode	Applies HTML encoding to a specified string
MapPath	Maps a specified path to a physical path
Transfer	Sends,(transfers), all the information created in one ASP file to another.
URLEncode	Applies URL encoding rules to a specified string

Examples:

When was a file last modified?

                <html>
                  <body>
                    <%
                      Set fs = Server.CreateObject("Scripting.FileSystemObject")
                      Set rs = fs.GetFile(Server.MapPath("demo_lastmodified.asp"))
                      modified = rs.DateLastModified
                    %>
                    This file was last modified on:
                    <%
                      response.write(modified)
                      Set rs = Nothing
                      Set fs = Nothing
                    %>
                  </body>
                </html>

Open a text file for reading

                <html>
                  <body>
                    <%
                      Set FS = Server.CreateObject("Scripting.FileSystemObject")
                      Set RS = FS.OpenTextFile(Server.MapPath("text") & "\TextFile.txt",1)
                      While not rs.AtEndOfStream
                        Response.Write RS.ReadLine
                        Response.Write("<br />")
                      Wend
                    %>
                    <p>
                      <a href="text/textfile.txt">
                        <img border="0" src="../images/btn_view_text.gif">
                      </a>
                    </p>
                  </body>
                </html>

Homemade hit counter

                <%
                  Set FS=Server.CreateObject("Scripting.FileSystemObject")
                  Set RS=FS.OpenTextFile(Server.MapPath("counter.txt"), 1, False)
                  fcount=RS.ReadLine
                  RS.Close
                  fcount=fcount+1
                  'This code is disabled due to the write access security on our server:
                  'Set RS=FS.OpenTextFile(Server.MapPath("counter.txt"), 2, False)
                  'RS.Write fcount
                  'RS.Close
                  Set RS=Nothing
                  Set FS=Nothing
                %>
                <html>
                  <body>
                    <p>
                      This page has been visited <%=fcount%>  times.
                    </p>
                  </body>
                </html>

ASPError Object (ASP 3.0)

The ASPError object is implemented in ASP 3.0 and it is only available in IISS.

The ASP Error object is used to display detailed information of any error that occurs in scripts in the ASP page. The ASPError object is created when Server.GetLastError is called, so the error information can only be accessed by using the Server.GetLastError method.

Example:

              <html>
                <body>
                  <%
                    'The following line creates an error
                    dim i for i=1 to 1 next
                    'Call the GetLastError() method to trap the error
                    dim objerr
                    set objerr=Server.GetLastError()
                    'The variable objerr now contains the ASPError object
                    response.write("ASP Code=" & objerr.ASPCode)
                    response.write("<br />")
                    response.write("Number=" & objerr.Number)
                    response.write("<br />")
                    response.write("Source=" & objerr.Source)
                    response.write("<br />")
                    response.write("Filename=" & objerr.File)
                    response.write("<br />")
                    response.write("LineNumber=" & objerr.Line)
                  %>
                </body>
              </html>

Properties

The ASPError object's properties are read-only.

Property	Description
ASPCode	Returns an error code generated by IIS.
ASPDescription	Returns a detailed description of the error If the error is ASP-related.
Category	Returns the source of the error ASP?, script?, object?
Column	Returns the column position inside the file that generated the error
Description	Returns a short description of the error
File	Returns the name of the ASP file that generated the error
Line	Returns the line number where the error was detected
Number	Returns the standard COM error code for the error
Source	Returns the source code of the line where the error occurred

ASP FileSystem Object

The FileSystemObject is used to access the file system on the server. This object can manipulate files, folders and directory paths, and retrieve file system information.

Properties

Property Description
Drives Returns a collection of all drive objects on the computer

Property	Description
Drives	Returns a collection of all drive objects on the computer

Methods

Method	Description
BuildPath	Appends a name to an exisiting path
CopyFile	Copies one or more files
CopyFolder	Copies one or more files
CreateFolder	Creates a new folder
CreateTextFile	Creates a text file and returns a TextStream object that can be used to read from or write to the file
DeleteFile	Deletes one or more files
DeleteFolder	Deletes one or more files
DriveExists	Checks if a drive exists
FileExists	Checks if a file exists
FolderExists	Checks if a folder exists
GetAbsolutPathName	Returns the complete path from the root
GetBaseName	Returns the base name of a specified file or folder
GetDrive	Returns a Drive object for the specified drive
GetDriveName	Returns the drive name of a specified path
GetExtensionName	Returns the file extension name for the last component in a specified path
GetFolder	Returns a Folder object for a specified path
GetParentFolderName	Reurns the name of the parent folder of the last component in a specified path
GetSpecialFolder	Returns the path to some of Window's special folders
GetTempName	Returns a randomly generated temporary file or folder
MoveFile	Moves one or more files
MoveFolder	Moves one or more files
OpenTextFile	Opens a file and returns a TExtStream object that can be used to access the file

Examples:

Create and Write to a text file:

                <%
                  dim fs,fname
                  set fs=Server.CreateObject("Scripting.FileSystemObject")
                  set fname=fs.CreateTextFile("c:\test.txt",true)
                  fname.WriteLine("Hello World!")
                  fname.Close
                  set fname=nothing
                  set fs=nothing
                %>

Determine if a file exists:

                <html>
                  <body>
                  <%
                    Set fs=Server.CreateObject("Scripting.FileSystemObject")
                    If (fs.FileExists("c:\winnt\cursors\3dgarro.cur"))=true Then
                      Response.Write("File c:\winnt\cursors\3dgarro.cur exists.")
                    Else
                      Response.Write("File c:\winnt\cursors\3dgarro.cur does not exist.")
                    End If
                    set fs=nothing
                  %>
                  </body>
                </html>

Determine if a folder exists:

                <html>
                  <body>
                  <%
                    Set fs=Server.CreateObject("Scripting.FileSystemObject")
                    If fs.FolderExists("c:\temp") = true Then
                      Response.Write("Folder c:\temp exists.")
                    Else
                      Response.Write("Folder c:\temp does not exist.")
                    End If
                    set fs=nothing
                  %>
                  </body>
                </html>

Determine if a drive exists:

                <html>
                  <body>
                  <%
                    Set fs=Server.CreateObject("Scripting.FileSystemObject")
                    if fs.driveexists("c:") = true then
                      Response.Write("Drive c: exists.")
                    Else
                      Response.Write("Drive c: does not exist.")
                    End If
                    Response.write("<br>")
                    if fs.driveexists("g:") = true then
                      Response.Write("Drive g: exists.")
                    Else
                      Response.Write("Drive g: does not exist.")
                    End If
                    set fs=nothing
                  %>
                  </body>
                </html>

Get the name of a drive:

                <html>
                  <body>
                  <%
                    Set fs=Server.CreateObject("Scripting.FileSystemObject")
                    p=fs.GetDriveName("c:\winnt\cursors\3dgarro.cur")
                    Response.Write("The drive name is: " & p)
                    set fs=nothing
                  %>
                  </body>
                </html>

Get the name of the parent folder for a path:

                <html>
                  <body>
                  <%
                    Set fs=Server.CreateObject("Scripting.FileSystemObject")
                    p=fs.GetParentFolderName("c:\winnt\cursors\3dgarro.cur")
                    Response.Write("The parent folder name of c:\winnt\cursors\3dgarro.cur is: " & p)
                    set fs=nothing
                  %>
                  </body>
                </html>

Get the file extension:

                <html>
                  <body>
                  <%
                    Set fs=Server.CreateObject("Scripting.FileSystemObject")
                    Response.Write("The file extension of the file 3dgarro is: ")
                    Response.Write(fs.GetExtensionName("c:\winnt\cursors\3dgarro.cur"))
                    set fs=nothing
                  %>
                  </body>
                </html>

Get the file name

                <html>
                  <body>
                  <%
                    Set fs=Server.CreateObject("Scripting.FileSystemObject")
                    Response.Write("The file name of the last component is: ")
                    Response.Write(fs.GetFileName("c:\winnt\cursors\3dgarro.cur"))
                    set fs=nothing
                  %>
                  </body>
                </html>

Get the base name of a file or folder

                <html>
                  <body>
                  <%
                    Set fs=Server.CreateObject("Scripting.FileSystemObject")
                    Response.Write(fs.GetBaseName("c:\winnt\cursors\3dgarro.cur"))
                    Response.Write("<br />")
                    Response.Write(fs.GetBaseName("c:\winnt\cursors\"))
                    Response.Write("<br />")
                    Response.Write(fs.GetBaseName("c:\winnt\"))
                    set fs=nothing
                  %>
                  </body>
                </html>

ASP TextStream Object

The TextSream object is used to access the contents of text files.

Properties

Property	Description
AtEndOfLine	Returns true if the file pointer is immediately before the end of line marker in a TextStream file, false if not
AtEndOfStream	Returns true if the file pointer is at the end of a TextStream file, false if not
Column	Returns the column number of the current character in an input stream
Line	Returns the current line number in a TextStream file

Methods

Method	Description
Close	Closes an open TextStream file
Read	Reads in a specified number of characters from a TextStream file
ReadAll	Reads in an entire TextStream file
ReadLine	Reads in one line from a TextStream file
Skip	Skips a specified number of characters when reading a TextStream file
SkipLine	Skips the next line when reading a TextStream file
Write	Writes specified text to a TextStream file
WriteLine	Writes specified text and a new line character to a TextStream file
WriteBlankLines	Writes a specified number of new line characters to a TextStream file

Examples:

Read a textfile

                <html>
                  <body>
                  <p>This is the text in the text file:</p>
                    <%
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set f=fs.OpenTextFile(Server.MapPath("testread.txt"), 1)
                      Response.Write(f.ReadAll)
                      f.Close
                      Set f=Nothing
                      Set fs=Nothing
                    %>
                  </body>
                </html>

Read only part of a textfile

                <html>
                  <body>
                  <p>This is the first five characters from the text file:</p>
                    <%
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set f=fs.OpenTextFile(Server.MapPath("testread.txt"), 1)
                      Response.Write(f.Read(5))
                      f.Close
                      Set f=Nothing
                      Set fs=Nothing
                    %>
                  </body>
                </html>

Read one line from a textfile

                <html>
                  <body>
                  <p>This is the first line of the text file:</p>
                    <%
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set f=fs.OpenTextFile(Server.MapPath("testread.txt"), 1)
                      Response.Write(f.ReadLine)
                      f.Close
                      Set f=Nothing
                      Set fs=Nothing
                    %>
                  </body>
                </html>

Read all lines from a textfile

                <html>
                  <body>
                  <p>This is all the lines in the text file:</p>
                    <%
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set f=fs.OpenTextFile(Server.MapPath("testread.txt"), 1)
                      do while f.AtEndOfStream = false
                        Response.Write(f.ReadLine)
                        Response.Write("<br>")
                      loop
                      f.Close
                      Set f=Nothing
                      Set fs=Nothing
                    %>
                  </body>
                </html>

Skip a part of a textfile

                <html>
                  <body>
                    <p>The first four characters in the text file are skipped:</p>
                    <%
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set f=fs.OpenTextFile(Server.MapPath("testread.txt"), 1)
                      f.Skip(4)
                      Response.Write(f.ReadAll)
                      f.Close
                      Set f=Nothing
                      Set fs=Nothing
                    %>
                  </body>
                </html>

Skip a line of a text file

                <html>
                  <body>
                    <p>The first line in the text file is skipped:</p>
                    <%
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set f=fs.OpenTextFile(Server.MapPath("testread.txt"), 1)
                      f.SkipLine
                      Response.Write(f.ReadAll)
                      f.Close
                      Set f=Nothing
                      Set fs=Nothing
                    %>
                  </body>
                </html>

Return the line number

                <html>
                  <body>
                  <p>This is all the lines in the text file (with line numbers):</p>
                    <%
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set f=fs.OpenTextFile(Server.MapPath("testread.txt"), 1)
                      do while f.AtEndOfStream = false
                        Response.Write("Line:" & f.Line & " ")
                        Response.Write(f.ReadLine)
                        Response.Write("<br>")
                      loop
                      f.Close
                      Set f=Nothing
                      Set fs=Nothing
                    %>
                  </body>
                </html>

Get the column number

                <html>
                  <body>
                  <%
                    Set fs=Server.CreateObject("Scripting.FileSystemObject")
                    Set f=fs.OpenTextFile(Server.MapPath("testread.txt"), 1)
                    Response.Write(f.Read(2))
                    Response.Write("<p>The cursor is now standing in position " &_
                                   f.Column & " in the text file.</p>")
                    f.Close
                    Set f=Nothing
                    Set fs=Nothing
                    %>
                  </body>
                </html>

Create a textfile and write text to it.

                <%
                  dim fs, f
                  set fs=Server.CreateObject("Scripting.FileSystemObject")
                  set f=fs.CreateTextFile("c:\test.txt",true)
                  f.WriteLine("Hello World!")
                  f.Close
                  set f=nothing
                  set fs=nothing
                %>

To create an instance of the TextStream object you can use the CreateTextFile or the OpenTextFile methods of the FileSystemObject object, or you can use the OpenAsTextStream method of the File object.

ASP Drive Object

The Drive object is used to return information about a local or network drive.

Use the Folder object to return information about the CONTENTS of a drive.

Properties

Property	Description
AvailableSpace	Returns the amount of available space on a specified drive
DriveLetter	Returns the drive letter identifier
DriveType	Returns the drive type
FileSystem	Returns the file system in use for a drive
FreeSpace	Returns the amount of free space on a drive
IsReady	Returns true if the drive is ready, false if not
Path	Returns the drive path
RootFolder	Returns the root folder for a drive
SerialNumber	Returns the serial number for a drive
ShareName	Returns the network share name for a drive
TotalSize	Returns the total size of a drive
VolumeName	Returns the volume name for a drive

Examples:

Get the total size of a drive.

                <%
                  Dim fs,d
                  Set fs=Server.CreateObject("Scripting.FileSystemObject")
                  Set d=fs.GetDrive("c:")
                  Response.Write("Drive " & d & ":")
                  Response.Write("Total size in bytes: " & d.TotalSize)
                  set d=nothing
                  set fs=nothing
                %>

Output:

                Drive c: Total size in bytes: 4293563392

Get the available space of a drive

                <html>
                  <body>
                    <%
                      Dim fs, d, n
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set d=fs.GetDrive("c:")
                      n = "Drive: " & d
                      n = n & "<br>Available Space in bytes: " & d.AvailableSpace
                      Response.Write(n)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Get the free space of a drive

                <html>
                  <body>
                    <%
                      Dim fs, d, n
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set d=fs.GetDrive("c:")
                      n = "Drive: " & d
                      n = n & "<br />Free Space in bytes: " & d.FreeSpace
                      Response.Write(n)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Get the total size of a drive

                <html>
                  <body>
                    <%
                      Dim fs,d,n
                      Set fs=Server.CreateObject("Scripting.FileSystemObject")
                      Set d=fs.GetDrive("c:")
                      n = "Drive: " & d
                      n = n & "<br>Total size in bytes: " & d.TotalSize
                      Response.Write(n)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Get the drive letter of a drive

                <html>
                  <body>
                    <%
                      dim fs, d, n
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set d=fs.GetDrive("c:")
                      Response.Write("The drive letter is: " & d.driveletter)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Gt the drive type of a drive

                <html>
                  <body>
                    <%
                      dim fs, d, n
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set d=fs.GetDrive("c:")
                      Response.Write("The drive type is: " & d.DriveType)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Get the file system of a drive

                <html>
                  <body>
                    <%
                      dim fs, d, n
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set d=fs.GetDrive("c:")
                      Response.Write("The file system is: " & d.FileSystem)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Is the drive ready?

                <html>
                  <body>
                    <%
                      dim fs,d,n
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set d=fs.GetDrive("c:")
                      n = "The " & d.DriveLetter
                      if d.IsReady=true then
                        n = n & " drive is ready."
                      else
                        n = n & " drive is not ready."
                      end if
                      Response.Write(n)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Get the path of a drive

                <html>
                  <body>
                    <%
                      dim fs,d
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set d=fs.GetDrive("c:")
                      Response.Write("The path is " & d.Path)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Get the root folder of a drive

                <html>
                  <body>
                    <%
                      dim fs,d
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set d=fs.GetDrive("c:")
                      Response.Write("The rootfolder is " & d.RootFolder)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Get the serial number of a drive

                <html>
                  <body>
                    <%
                      dim fs,d
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set d=fs.GetDrive("c:")
                      Response.Write("The serialnumber is " & d.SerialNumber)
                      set d=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

ASP File Object

The ASP File object is used to return information about a specified file

Properties

Property	Description
Attributes	Sets/Returns the attibutes of a file
DateCreated	Returns date and time a file was created
DateLastAccessed	Returns the date and time a file was last accessed
DateLastModified	Returns the date and time a file was last modified
Drive	Returns the drive of the file
Name	Sets/Returns the file name
ParentFolder	Returns the folder object for the parent of a file
Path	Returns the file's path
ShortName	Returns the 8.3 short name for a file
ShortPath	Returns the 8.3. short path of a file
Size	Returns the size in bytes of a file
Type	Returns the file type

Methods

Method	Description
Copy	Copies a file to another location
Delete	Deletes a file
Move	Moves a file to another location
OpenAsTextStream	Opens a file and returns a TextStream object to be used to access the file

Examples

Return the date/time created

                <html>
                  <body>
                    <%
                      dim fs, f
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set f=fs.GetFile(Server.MapPath("testread.txt"))
                      Response.Write("The file testread.txt was created on: " &_
                                      f.DateCreated)
                      set f=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Return the date/time last modified

                <html>
                  <body>
                    <%
                      dim fs, f
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set f=fs.GetFile(Server.MapPath("testread.txt"))
                      Response.Write("The file testread.txt was last modified on: " &_
                                      f.DateLastModified)
                      set f=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Return the date/time last accessed

                <html>
                  <body>
                    <%
                      dim fs, f
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set f=fs.GetFile(Server.MapPath("testread.txt"))
                      Response.Write("The file testread.txt was last accessed on: " &_
                                      f.DateLastAccessed)
                      set f=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

Return the file's attributes

                <html>
                  <body>
                    <%
                      dim fs,f
                      set fs=Server.CreateObject("Scripting.FileSystemObject")
                      set f=fs.GetFile(Server.MapPath("testread.txt"))
                      Response.Write("The attributes of the file testread.txt are: " &_
                                      f.Attributes)
                      set f=nothing
                      set fs=nothing
                    %>
                  </body>
                </html>

ASP Folder Object

The ASP Folder object is used to returns information about a specified folder.

Collections

Collection	Description
Files	Returns a collection of all the files in a folder
SubFolders	Returns a collection of all the sub folders in a folder

Properties

Property	Description
Attributes	Sets/Returns the attributes of a folder
DateCreated	Returns date/time a folder was created
DateLastAccessed	Returns date/time a folder was last accessed
DateLastModified	Returns date/time a folder was last modified
Drive	Returns the drive letter where the folder resides
IsRootFolder	Returns true if it is the root folder
Name	Sets/Returns the name of the folder
ParentFolder	Returns the parent folder
Path	Returns the path of a folder
ShortName	Returns the 8.3 short name for a folder
ShortPath	Returns the 8.3 short path of a folder
Size	Returns the size of a folder
Type	Returns the type of the folder

Methods

Method	Description
Copy	Copies a folder to another location
Delete	Deletes a folder
Move	Moves a folder to another location
CreateTextFile	Creates a new text file in the folder and returns a TextStream object to access it

Examples

Return the date/time a folder was created

                <%
                  Dim fs,fo
                  Set fs=Server.CreateObject("Scripting.FileSystemObject")
                  Set fo=fs.GetFolder("c:\test")
                  Response.Write("Folder created: " & fo.DateCreated)
                  set fo=nothing
                  set fs=nothing
                %>

Output:

                Folder created: 10/22/2001 10:01:19 AM

ASP Dictionary Object

The Dictionary object is used to store information in name/value pairs, refferred to as key and item... similar to arrays, but are non-multidimensional, have more built in functions, and access the data better than array's.

Properties

Property	Description
CompareMode	Sets/Returns the comparison mode for comparing keys in a dictionary object
Count	Returns the number of key/item pairs in a dictionary object
Item	Sets/Returns the value of an item in a dictionary object
Key	Sets a new key value for an existing key value in a dictionary object

Methods

Method	Description
Add	Adds a new key/item to a dictionary object
Exists	Returns boolean indicating if a key exists in the dictionary object
Items	Returns an array of all the items in a dictionary object
Keys	Returns an array of all the keys in a dictionary object
Remove	Removes one key/item pair from the dictionary object
RemoveAll	Removes all key/item pairs from a dictionary object

Examples:

Create a dictionary object, add key/item pairs and return the item value for the key "gr"

                <%
                  Dim d
                  Set d=Server.CreateObject("Scripting.Dictionary")
                  d.Add "re","Red"
                  d.Add "gr","Green"
                  d.Add "bl","Blue"
                  d.Add "pi","Pink"
                  Response.Write("The value of key gr is: " & d.Item("gr"))
                %>

Output:

                The value of key gr is: Green

Determine if a key exists

                <html>
                  <body>
                    <%
                      dim d
                      set d=Server.CreateObject("Scripting.Dictionary")
                      d.Add "n", "Norway"
                      d.Add "i", "Italy"
                      if d.Exists("n")= true then
                        Response.Write("Key exists.")
                      else
                        Response.Write("Key does not exist.")
                      end if
                      set d=nothing
                    %>
                  </body>
                </html>

Return an array of all items

                <html>
                  <body>
                    <%
                      dim d,a,i,s
                      set d=Server.CreateObject("Scripting.Dictionary")
                      d.Add "n", "Norway"
                      d.Add "i", "Italy"
                      Response.Write("<p>The values of the items are:</p>")
                      a=d.Items
                      for i = 0 To d.Count -1
                        s = s & a(i) & "<br>"
                      next
                      Response.Write(s)
                      set d=nothing
                    %>
                  </body>
                </html>

Return an array of all keys

                <html>
                  <body>
                    <%
                      dim d,a,i,s
                      set d=Server.CreateObject("Scripting.Dictionary")
                      d.Add "n", "Norway"
                      d.Add "i", "Italy"
                      Response.Write("<p>The value of the keys are:</p>")
                      a=d.Keys
                      for i = 0 To d.Count -1
                        s = s & a(i) & "<br>"
                      next
                      Response.Write(s)
                      set d=nothing
                    %>
                  </body>
                </html>

Return the value of an item

                <html>
                  <body>
                    <%
                      dim d
                      set d=Server.CreateObject("Scripting.Dictionary")
                      d.Add "n", "Norway"
                      d.Add "i", "Italy"
                      Response.Write("The value of the item n is: " & d.item("n"))
                      set d=nothing
                    %>
                  </body>
                </html>

Set a key

                <html>
                  <body>
                    <%
                      dim d
                      set d=Server.CreateObject("Scripting.Dictionary")
                      d.Add "n", "Norway"
                      d.Add "i", "Italy"
                      d.Key("i") = "it"
                      Response.Write("The key i has been set to it, and the value is: " & d.Item("it"))
                      set d=nothing
                    %>
                  </body>
                </html>

Return the number of key/item pairs

                <html>
                  <body>
                    <%
                      dim d, a, s, i
                      set d=Server.CreateObject("Scripting.Dictionary")
                      d.Add "n", "Norway"
                      d.Add "i", "Italy"
                      Response.Write("The number of key/item pairs is: " & d.Count)
                      set d=nothing
                    %>
                  </body>
                </html>

ASP AdRotator Component

The ASP AdRotator component creates an AdRotator object that displays a different image each time a user enters or refreshes a page. A text file includes information about the images.

Syntax

              <%
                set adrotator=server.createobject("MSWC.AdRotator")
                adrotator.GetAdvertisement("textfile.txt")
              %>

Properties

Property	Description	Example
Border	Specifies the border size	<% set adrot=Server.CreateObject("MSWC.AdRotator") adrot.Border="2" Response.Write(adrot.GetAdvertisement("ads.txt")) %>
Clickable	Specifies a link	<% set adrot=Server.CreateObject("MSWC.AdRotator") adrot.Clickable=false Response.Write(adrot.GetAdvertisement("ads.txt")) %>
TargetFrame	Name of the frame to display the ad	<% set adrot=Server.CreateObject("MSWC.AdRotator") adrot.TargetFrame="target='_blank'" Response.Write(adrot.GetAdvertisement("ads.txt")) %>

Methods

Method	Description	Example
GetAdvertiesment	Returns the HTML that displays the ad	<% set adrot=Server.CreateObject("MSWC.AdRotator") Response.Write(adrot.GetAdvertisement("ads.txt")) %>

Examples:

Assume the following file "banners.asp"

                <%
                  url=Request.QueryString("url")
                  If url<>"" then Response.Redirect(url)
                %>
                <html>
                  <body>
                    <%
                      set adrotator=Server.CreateObject("MSWC.AdRotator")
                      response.write(adrotator.GetAdvertisement("ads.txt"))
                    %>
                  </body>
                </html>

The file "ads.txt" looks like this

                REDIRECT banners.asp
                WIDTH 460
                HEIGHT 60
                BORDER 0
                *
                w3schools.gif
                http://www.w3schools.com/
                Visit W3Schools
                80
                microsoft.gif
                http://www.microsoft.com/
                Visit Microsoft
                20

The lines below the asterisk in the file "ads.txt" spcify the images to be displayed, the hyperlink addresses, the alternate text for the images and the display rates in percent of the hits. The W3Schools image will be displayed for 80% of the hits and the Microsoft image will be displayed for 20% of the hits.

The redirection page "banners.asp" will receive a querystring with a variable named URL containing the URL to goto.

ASP Browser Capabilties Component

The ASP browser capabilities component creates a browser type object that determines the type, capabilities and version number of each browser that visits the site.

When a browser connects to a server, an HTTP user agent header is also sent to the server. This heder contains information about the browser. The BrowserType object compares the information in the header with information in a file on the server called "Browscap.ini".

If there is a match between the browser type and the version number sent in the header and the information in the "Browsercap.ini" file, you can use the BrowserType object to list the properties of the matching browser. If there is no match for the browser type and version number it will set every property to "UNKNOWN".

Syntax

              <%
                Set MyBrow=Server.CreateObject("MSWC.BrowserType")
              %>

Examples:

Determine the type, capabilities and version number of each browser.

                <html>
                  <body>
                    <%
                      Set MyBrow=Server.CreateObject("MSWC.BrowserType")
                    %>
                    <table border="1" width="65%">
                       <tr>
                         <td width="52%">Client OS</td>
                         <td width="48%"><%=MyBrow.platform%></td>
                       </tr>
                       <tr>
                         <td >Web Browser</td>
                         <td ><%=MyBrow.browser%></td>
                       </tr>
                       <tr>
                         <td>Browser version</td>
                         <td><%=MyBrow.version%></td>
                       </tr>
                       <tr>
                         <td>Frame support?</td>
                         <td><%=MyBrow.frames%></td>
                       </tr>
                       <tr>
                         <td>Table support?</td>
                         <td><%=MyBrow.tables%></td>
                       </tr>
                       <tr>
                         <td>Sound support?</td>
                         <td><%=MyBrow.backgroundsounds%></td>
                       </tr>
                       <tr>
                         <td>Cookies support?</td>
                         <td><%=MyBrow.cookies%></td>
                       </tr>
                       <tr>
                         <td>VBScript support?</td>
                         <td><%=MyBrow.vbscript%></td>
                       </tr>
                       <tr>
                         <td>JavaScript support?</td>
                         <td><%=MyBrow.javascript%></td>
                       </tr>
                    </table>
                  </body>
                </html>

The Browscap.ini File

The Browsercap.ini file is used to declare properties and to set default values for browsers.

the "Browsercap.ini" file can contain the following

                [;comments]
                [HTTPUserAgentHeader]
                [parent=browserDefinition]
                [property1=value1]
                [propertyN=valueN]
                [Default Browser Capability Settings]
                [defaultProperty1=defaultValue1]
                [defaultPropertyN=defaultValueN]

Example Browsercap.ini file.

                  ;IE 5.0
                  [IE 5.0]
                  browser=IE
                  Version=5.0
                  majorver=#5
                  minorver=#0
                  frames=TRUE
                  tables=TRUE
                  cookies=TRUE
                  backgroundsounds=TRUE
                  vbscript=TRUE
                  javascript=TRUE
                  javaapplets=TRUE
                  ActiveXControls=TRUE
                  beta=False;DEFAULT BROWSER
                  [*]
                  browser=Default
                  frames=FALSE
                  tables=TRUE
                  cookies=FALSE
                  backgroundsounds=FALSE
                  vbscript=FALSE
                  javascript=FALSE

Parameters

Parameter	Description
comments	Optional Any line that starts with a semicolon is ignored by the BrowserType object
HTTPUserAgentHeader	Optional Specifies the HTTP User Agent header to associate with the browser-property value statements specified in propertyN. Wildcard characters are allowed.
browserDefinition	Optional Specifies the HTTP User Agent header-string of a browser to use as the parent browser. The current browser's definition will inherit all of the property values declared in the parent.
propertyN	Optional Specifies the browser properties listed below. ActiveXControls - Supports ActiveX� controls? Backgroundsounds - Supports background sounds? Cdf - Supports channel definition format for webcasting? Tables - Supports tables? Cookies - Supports cookies? Frames - Supports frames? Javaapplets - Supports java applets? Javascript - Supports javascript? Vbscript - Supports vbscript? Browser - Specifies the name of the browser Beta - Is the browser beta software? Platform - Specifies the platform of the browser Version - Specifies the version of the browser
valueN	Optional Specifies the value of propertyN. Can be a string, an integer,(prefix with #), or boolean
defaultPropertyN	Optional Specifies the name of the browser property to which to assign a default value if none of the defined HTTPUserAgentHeader values match the HTTP User Agent Header sent by the browser
defaultValueN	Optional Specifies the value of defaultPropertyN. Can be a string, an integer,(prefix with #), or boolean

ASP Content Linking Component

The ASP Content Linking component is used to create a quick and easy navigation system by returning a Nextlink object that is used to hold a list of web pages to be navigated.

Syntax

              <%
                Set nl=Server.CreateObject("MSWC.NextLink")
              %>

First create a text file,"links.txt", which contains the pages to be navigated. The pages must be listed in the same order you want them to be displayed and it must also contain a description for each file name,(use the tab key to separate file name from description).

Modify the text file if you want to add a page or change the order of the pages in the list.

"links.txt"

                asp_intro.asp ASP Intro
                asp_syntax.asp ASP Syntax
                asp_variables.asp ASP Variables
                asp_procedures.asp ASP Procedures

On each of the pages listed above, put one line of code:

                <!-- #include file="nlcode.inc" -->

This line will include the code below on every page listed in "links.txt" and the navigation will work properly.

"nlcode.inc":

                <%
                  'Use the Content Linking Component
                  'to navigate between the pages listed
                  'in links.txt
                  dim nl
                  Set nl=Server.CreateObject("MSWC.NextLink")
                  if (nl.GetListIndex("links.txt")>1) then
                    Response.Write("<a href='" & nl.GetPreviousURL("links.txt"))
                    Response.Write("'>Previous Page</a>")
                  end if
                  Response.Write("<a href='" & nl.GetNextURL("links.txt"))
                  Response.Write("'>Next Page</a>")
                %>

Methods

Method	Description	Example
GetListCount	Returns the number of items listed in the content linking list file	<% dim nl,c Set nl=Server.CreateObject("MSWC.NextLink") c=nl.GetListCount("links.txt") Response.Write("There are ") Response.Write(c) Response.Write(" items in the list") %> Output: There are 4 items in the list
GetListIndex	Returns the index number of the current item in the Content Linking List file. The index number of the first item is 1.0 and is returned if the current page is not in the Content Linking List file.	<% dim nl,c Set nl=Server.CreateObject("MSWC.NextLink") c=nl.GetListIndex("links.txt") Response.Write("Item number ") Response.Write(c) %> Output: Item number 3
GetNextDescription	Returns the text description of the next item listed in the Content Linking List file. If the current page is not found in the list file, it returns the text description of the last page on the list.	<% dim nl,c Set nl=Server.CreateObject("MSWC.NextLink") c=nl.GetNextDescription("links.txt") Response.Write("Next ") Response.Write("description is: ") Response.Write(c) %> Next description is: ASP Variables
GetNextURL	Returns the URL of the next item listed in the Content Linking List file. If the current page is not found in the list file, it returns the URL of the last page on the list.	<% dim nl,c Set nl=Server.CreateObject("MSWC.NextLink") c=nl.GetNextURL("links.txt") Response.Write("Next ") Response.Write("URL is: ") Response.Write(c) %> Next URL is: asp_variables.asp
GetNthDescription	Returns the description of the Nth page listed in the Content Linking list file	<% dim nl,c Set nl=Server.CreateObject("MSWC.NextLink") c=nl.GetNthDescription("links.txt",3) Response.Write("Third ") Response.Write("description is: ") Response.Write(c) %> Third description is: ASP Variables
GetNthURL	Returns the URL of the Nth page listed in the Content Linking list file	<% dim nl,c Set nl=Server.CreateObject("MSWC.NextLink") c=nl.GetNthURL("links.txt",3) Response.Write("Third ") Response.Write("URL is: ") Response.Write(c) %> Third URL is: asp_variables.asp
GetPreviousDescription	Returns the text description of the previous item listed in the Content Linking list file. If the current page is not found in the list file, it returns the text description of the first page on the list	<% dim nl,c Set nl=Server.CreateObject("MSWC.NextLink") c=nl.GetPreviousDescription("links.txt") Response.Write("Previous ") Response.Write("description is: ") Response.Write(c) %> Previous description is: ASP Variables
GetPreviousURL	Returns the URL fthe previous item listed in the Content Linking List file. If the current page is not found in the list file, it returns the URL of the first page on the list	<% dim nl,c Set nl=Server.CreateObject("MSWC.NextLink") c=nl.GetPreviousURL("links.txt") Response.Write("Previous ") Response.Write("URL is: ") Response.Write(c) %> Previous URL is: asp_variables.asp

Examples

Use the Content Linking Component to build a table of contents.

                <html>
                  <body>

                    <p>
                      The example below builds a table of contents.
                    </p>

                    <%
                      dim c
                      dim i
                      set nl=server.createobject("MSWC.Nextlink")
                      c = nl.GetListCount("text\links.txt")
                      i = 1
                    %>
                    <ul>
                      <%do while (i <= c) %>
                        <li><a href="<%=nl.GetNthURL("text\links.txt", i)%>">
                        <%=nl.GetNthDescription("text\links.txt", i)%></a>
                        <%
                        i = (i + 1)
                      loop
                    %>
                    </ul>
                    <p>
                      The text file contains a list of page urls and link descriptions.
                      It contains one line of text for each page. Note that the url and
                      description MUST be separated by the TAB character.
                    </p>
                    <p>
                      <a href="text/links.txt">
                        <img border="0" src="/images/btn_view_text.gif">
                      </a>
                    </p>
                  </body>
                </html>

Use the Content Linking Component to navigate between the pages in a text file.

          <html>
            <body>

              <h1>This is page 1!</h1>

              <%
                Set nl=Server.CreateObject("MSWC.NextLink")
                If (nl.GetListIndex("text/links2.txt")>1) Then
              %>
              <a href="<%Response.Write(nl.GetPreviousURL("text/links2.txt"))%>">Previous Page</a>
              <%End If%>

              <a href="<%Response.Write(nl.GetNextURL("text/links2.txt"))%>">Next Page</a>

              <p>
                The example uses the Content Linking Component
                to navigate between the pages in a text file.
              </p>

              <p>
                <a href="text/links2.txt">
                  <img border="0" src="/images/btn_view_text.gif">
                </a>
              </p>
            </body>
          </html>

ASP Content Rotator Component

The Content Rotator Component creates a ContentRotator object that displays a different HTML content string each time a user visits or refreshes a page. A text file called the Content Schedule File contains the information about the content strings. The content strings can contain HTML tags so you can display any type of content that HTML can represent: text, images, colors and links.

Examples:

              <html>
                <body>

                  <p>
                    <b>Note:</b> This example won't work because ASP 3.0 is not installed
                                 on our server.
                  </p>

                  <p>
                    <a href="demo_textads.asp">
                      <img border="0" src="/images/btn_view_text.gif">
                    </a>
                  </p>

                  <%
                    set cr=server.createobject("MSWC.ContentRotator")
                    response.write(cr.ChooseContent("text/textads.txt"))
                  %>

                  <p>
                    NOTE: Because the content strings are changed randomly in the text file,
                          and this page has only four content strings to choose from,
                          sometimes the page will display the same content strings twice
                          in a row.
                  </p>

                </body>
              </html>

Syntax

                <% Set cr=Server.CreateObject("MSWC.ContentRotator") %>

The following example displays different content each time a user views the page. Create a text file named "textads.txt" in your default web site folder in a subfolder called text.

"textads.txt":

                %% #1
                This is a great day!!

                %% #2
                <h1>Smile</h1>

                %% #3
                <img src="smiley.gif">

                %% #4
                Here's a <a href="http://www.w3schools.com">link.</a>

The #number at the beginning of each content string is an optional parameter that indicates the relative weight of the HTML content string, the higher the number, the more often it gets displayed.

Next crate an ASP file and insert the following code:

                <html>
                  <body>

                    <%
                      set cr=server.createobject("MSWC.ContentRotator")
                      response.write(cr.ChooseContent("text/textads.txt"))
                    %>

                  </body>
                </html>

Methods

Method	Description	Example
ChooseContent	Gets and displays a content string from the file	<% dim cr Set cr=Server.CreateObject("MSWC.ContentRotator") response.write(cr.ChooseContent("text/textads.txt")) %>
GetAllContent	Retrieves and displays all content strings in the file	<% dim cr Set cr=Server.CreateObject("MSWC.ContentRotator") response.write(cr.GetAllContent("text/textads.txt")) %>

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