Explain ASP (Active Server Pages) and ASP Objects?

CGI scripting is failed to fulfill the client requirements. ASP’s and JSP’s satisfy the client requirements ASP’s was developed by Microsoft to run along its web server internet information server (IIS). Both IIS and ASP work on windows operating system. ‘Install’ and configure, IIS, Apache and ASP is very easy almost everyone can do.

           

Asp is very  efficient  at  run time  when compared  to  traditional CGI  scripting  ASP extends  the  html  page by  embedding  serves side scripting in to a html . These scripts are  processed by suitable  web serves and the processed  page  send to the browser.

ASP developers will use either  java script (or) VB  script  as scripting  languages.

ASP  Objects:-

Objects are things which  have defined  boundaries  and whose  internals are  usually hide from the world. Objects  provide services for  other  parts  of an application  through  their methods. A methods is just  like  a function . ASP  technology  define  five objects   which  can be  used  in your  scripts. All names will  start  with a  capital  letter. All of you have to follow  this  convention.

1.Request  object

2.Response object

3.Server  object

4.Session  object

5.Application object.

Request object: -

Asp contain its  built – in object to take a lot  of handling form data.

In CGI model of web development each programmer must handle requests from uses in their own way.

ASP has its own functionality for extracting data from client requests whether sent with the post and get method.

Data sent by user is packaged as a request object. The request object may contain a number of different data items but the most important ones are about cookies data sent via post. And data sent via get.

Response object:- 

After reading the description of request object you must able to send response. Response object control the transmission of data from the server to the web browser.

Using Response – write() property of response object dynamically create html. The response object has a Response- Buffer ( ) property which you can ‘send to’ or to cache’ the page before sending. Cache is important when you are getting lots of data and want the user to see the whole page rather than just part of it.

HTML pages can have an expiry time. This can be set from the ASP script and is measured in minutes. from the time that the browser receives the page the expiry time is set through Response – expires(). Browser’s can be automatically redirected to another site by using Response –Redirect( ).

Server object:- 

The server object holds information about the web server itself and lets you use some of its functionality. For eg;- you can set the max time that a script will execute before generating an error.

A method called Server – HTML Encode() will convert characters such as “<” into their HTML equivalent such as ‘<’ automatically when you are processing the data from dbase for inclusion in web pages.

Session object:- 

‘http’ is stateless and has no concept of a session. There are two ways of creating artificial web sessions.

® By adding hidden form fields to form.

® By using cookies.

ASP provides a third option called a session this uses cookies but they are set by the server itself not by the programmer and valid only for a limited time Using Session the following sequence happens

(1) The user request a page any cookies are valid for the server are returned along with the page.

(2) If no cookies are sent  a new session  is created and a cookie is set on the browser.

(3) If cookies were sent they are checked to see if that one is a ASP session ID.

(4) If the cookie has time out a new session is created and a new cookie is set.

(5) If the cookie is valid and not timed out the existing session is recreated some memory

Application object:- 

This is used to share data within a web application. It is basically a developer design set of pages within a site (or) set of sites on one server.