ASP Quick Reference

Welcome to The Coding College! This ASP Quick Reference provides a concise overview of the key components, objects, and syntax of Classic ASP to help developers quickly find the information they need. Whether you’re building dynamic web applications or maintaining legacy systems, this guide will save you time and boost your productivity.

What Is Classic ASP?

Active Server Pages (ASP) is a server-side scripting environment for creating dynamic and interactive web pages. It was developed by Microsoft and commonly used before the introduction of ASP.NET. Classic ASP enables embedding server-side code within HTML pages using VBScript or JScript.

Key Components of ASP

1. Built-In Objects

ASP includes several objects to simplify web development:

ObjectDescription
RequestRetrieves user input from forms, query strings, or cookies.
ResponseSends output to the browser, manages headers, and redirects pages.
SessionStores user-specific data for the duration of the user’s session.
ApplicationShares data across all users of the application.
ServerProvides methods and properties for server-related operations.
ASPErrorHandles error information for debugging and troubleshooting.

2. Common Directives

Directives control the behavior of ASP pages.

DirectiveDescription
@LanguageSpecifies the scripting language (e.g., VBScript, JScript).
@EnableSessionStateEnables or disables session state for a page.
@CodePageSets the character set for the page.

Example:

<%@ Language="VBScript" %>

3. Key Methods

Request Object

  • Retrieve form values: 
Request.Form("inputName")
  • Retrieve query string values: 
Request.QueryString("paramName")

Response Object

  • Write output: 
Response.Write("Hello, World!")
  • Redirect to another page: 
Response.Redirect("newPage.asp")

Session Object

  • Store session data: 
Session("username") = "JohnDoe"
  • Retrieve session data: 
user = Session("username")

Application Object

  • Store application-wide data: Application("siteName") = "The Coding College"

4. Error Handling

ASP provides robust error-handling mechanisms using the On Error statement.

Example:

On Error Resume Next
' Code that might cause an error
If Err.Number <> 0 Then
    Response.Write("An error occurred: " & Err.Description)
    Err.Clear
End If

ASP Syntax Cheat Sheet

Basic Syntax

  • Embed server-side code: 
<% ' Your code here %>
  • Write to the browser: 
<% Response.Write("Welcome to ASP!") %>

Variables

  • Declare a variable: 
Dim myVar
myVar = "Hello"

Conditional Statements

If condition Then
    ' Code block
Else
    ' Code block
End If

Loops

  • For Loop: 
For i = 1 To 10
    Response.Write(i & "<br>")
Next
  • While Loop: 
While condition
    ' Code block
Wend

Functions

Function AddNumbers(a, b)
    AddNumbers = a + b
End Function

ASP Components

ASP includes several built-in components for advanced functionality:

ComponentDescription
AdRotatorDisplays rotating advertisements.
ContentRotatorDisplays random or rotating content.
Browser CapabilitiesDetects user browser capabilities.

ASP Best Practices

  1. Enable Error Handling:
    • Always use error handling to identify and resolve issues during development.
  2. Optimize Performance:
    • Use session and application variables judiciously to avoid overloading the server.
  3. Sanitize Input:
    • Prevent SQL injection and cross-site scripting (XSS) by sanitizing user input.

Conclusion

Classic ASP remains a valuable tool for maintaining and updating legacy systems. With this Quick Reference Guide, developers can efficiently use the most critical aspects of ASP. For more in-depth tutorials, explore our website, The Coding College, where we provide hands-on coding examples and tips for mastering web technologies.

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