Client Side Scripting and Server Side Scripting

Client-Side Scripting

In this technique, one uses the user’s browser to checking the form data. If data is missing or is incorrect, the browser can prompt the user to take corrective action.

This way, the form data is sent to the server-side script only after it has been established that the collected data is complete and correct.

Server-Side Scripts: Review

Are programs that reside on Web servers receive info that a user enters in a form process that info and take appropriate action.

Examples:

CGI scripts on Unix servers

ASP scripts on Windows servers

New Concept: Client-Side Scripts

Small programs that are a part of the Web page and run on the user’s (client’s) computer

They interact with the user to collect info or to accomplish other tasks.

Once it has been collected, they may help pass the collected info on to a server-side script.

We’ll use JavaScript to do client-side scripting. However, there are many other languages that can be used for that purpose, e.g. VBScript.

Advantages of Client-Side Scripting

Reduced server load as it does not have to send messages to the user’s browser about missing or incorrect data

Reduced network traffic as the form’s data is sent only once instead of many to’s and fro’s.

Disadvantages

Client-side scripts do not work with all browsers.

Some user intentionally turns scripting off on their browsers.

This increases the complexity of the Web page, as it now has to support both situations:

Browsers with scripting capability, and those not having that capability.