Dynamic Web Pages Brad Polzar March 8, 2007
Jan 01, 2016
Dynamic Web PagesBrad Polzar March 8, 2007
Outline
• What are Dynamic Web Pages?
• Server Side Dynamics• Active Server Pages• Hypertext Preprocessor
• Client Side Dynamics• JavaScript• Java Applets• Flash
What is a dynamic Web Page?
• General Definition:• A web page that changes based on the input of the
user outside of navigating to another page.
• A more specific definition:• A web page that dynamically decides what to
display given the user’s actions and/or conditions that are currently met.
• A really picky one:• A web page that is the result of a server
dynamically deciding what html code to send based on user actions and currently met conditions.
Server Side
• Premise
• Server Side Scripting• Active Server Pages• Hypertext Preprocessor
Active Server Pages (ASP)
• Microsoft’s version of dynamic web pages
• Can use one of four scripting languages:• VBScript• JScript• PerlScript• Python
• Server Requirements• Instant ASP (iASP)• Chili!ASP• Can also run on other platforms
An ASP Page
• Embedded into an html page
• Tags• <% and %>
• <%@ Language= %>
• <script> and </script>
<%@ Language=VBScript %>
<html>
<body>
<% Response.Write(“Hello World!”) %>
</body>
</html>
The Browser’s Code
<html>
</body>
Hello World!
</body>
</html>
<%@ Language=VBScript %>
<html>
</body>
<% Response.Write(“Hello World!”) %>
</body>
</html>
ASP Collections
• Similar to a sorted array• Name / Value pairs
• Name: Brad• Class: CS4110• Date: Mar 8, 2007
Name Brad
Class CS4110
Date Mar 8, 2007
ASP Objects
• Response Object
• Request Object
• Session Object
• Application Object
• Server Object
• ObjectContext Object
• ASPError Object
Response Object
• Deals with the response to the client
• Methods• Write• Redirect• Flush• End • Clear
• Handles writing cookies
Request Object
• Deals with the request to the server
• Collections• Cookies• Query String• Form
QueryString and Form
• Both pass information from client to server
• QueryString• Passes through URL• http://www.mywebsite.com/asp?querystring• …?field1=value&field2=value2&…• Request.QueryString(field1)
• Form• Passes through request• Request.Form(field1)
Getting QueryString and Form Info
• Use html forms
• To pass via QueryString• <form method=“get”>
• To pass via Form• <form method=“post”>
Cookies
• Stored on client’s computer• Automatically sent with request• Pros:
• Keeps info off of server• Fairly small
• Cons:• Doesn’t maintain account across multiple
computers• Not all computers allow• Expiration• Only simple data types
Creating Cookies
• Simple Cookie – one value• <% Response.Cookies(“varName”) = “value” %>
• Will create if it doesn’t exist• Will overwrite if does• MUST DO THIS BEFORE THE <html> TAG!
• Complex Cookie – A Cookie with Keys• Can set a cookie to have multiple values<%
Response.Cookies(“cookieName”)(“field1”) = “value1”
Response.Cookies(“cookieName”)(“field2”) = “value2”
%>
Reading Cookies
• Will automatically send with request• <% var = Request.Cookies(“varName”) %>
• Will return “” if varName is not a cookie
Session Object
• Holds information of client’s current session
• Uses: Stores complex info• Objects• Arrays
• Negatives:• Session ending time• Space on server• Server Performance• Used through cookies
Application Object
• Keeps state of the server
• Only one instance
• Used for data that is global and changed often
Reading and Writing Files
• Databases
• Text Files
ASP.Net
• Same Objects as ASP
• Uses .Net Common Runtime Languages• Visual Basic• Visual C#• Visual J#
Hypertext Preprocessor (PHP)
• Used to stand for Personal Home Page
• Uses Apache Server
• Is a scripting language
• Is also a dynamic web technology
• Current versions are PHP4 and PHP5
A PHP Page
• Tags• <?php and ?>• <script language=“php”> and </script>• <% and %>
PHP syntax
• Instruction separation - ;
• Comments
• Variables• Start with $• Continue with name
• Must start with _ or a letter
• No type defined
PHP variables
• Eight types• Four primitive
• Integer• Floating point• String• Boolean
• Two compound• Object• Array
• Two special• Resource• NULL
PHP Variables Con’t
• PHP4 – can assign by reference
• Don’t have to initialize• Default values
• Integer and Floating Point: 0• String: empty string• Boolean: False• Array: empty array
PHP SuperGlobals
• SuperGlobal• Def: predefined variables global in every scope
• $GLOBALS• $_SERVER• $_GET• $_POST• $_COOKIES• $_FILE• $_ENV• $_REQUEST• $_SESSION
PHP Database Support
• Formats supported• Access• SQL• MySQL• Oracle
Client-Side Scripting
• Premise
• JavaScript
• VBScript
JavaScript
• Not simple Java
• Procedural Script
• Object-Orientated Script• Objects created at run-time
• Intrinsic Objects• Number• String• Boolean• Date
Client-side Scripting
• Accessing Scripts• Include in HTML document• Reference another file
• Access to client’s computer
Other Dynamic Utilities
• Flash
• Java Applets
Works Consulted• Mitchell, Scott and Atkinson, James. (2000) Sams Teach
Yourself Active Server Pages 3.0 in 21 Days. Indiapolis, IN: Sams.
• Achour, Mehdi, et al. (2007) PHP Manual. http://www.php.net/manual/en/.
• w3schools.com “ASP Tutorial.” Retrieved March 5, 2007 from http://www.w3schools.com/asp/default.asp.
• Wikipedia.org (2007) “ASP.Net.” Retrieved March 5, 2007 from http://en.wikipedia.org/wiki/ASP.NET.
• Flanagan, David. (1998) JavaScript: The Definitive Guide. Sebastopol, CA: O’Reilly.