Client-Side Validation with Javascript by Daniel Yee

Client-Side Scripting Language Javascript European Computer Manufacturers Association (ECMA) ECMA-262 Third edition Updated Last December 1999

Javascript Not a full fledged programming language Cannot connect to databases Limited interactions to system resources Cannot do tasks most web databases require

Common Uses of Javascript Validation of <form> data Simple interaction with <form> data Adding dynamic elements to web page

Benefits of using Javascript Faster response then using server-side validation Reduction in web-server load Reduction in network traffic Can be saved as a file - file.js and reused by typing <script type= text/javascript src=“file.js”>

Warning!!!!!!!!!!!!! Never rely on client-side validation as the only method of ensuring requirements and constraints Javascript can be bypassed by the user through design, error, or configuration

Validating <form> Data Simple example for validating a <form> with JavaScript Check for whitespace

Batch Error Reporting Validation for multiple fields Example

Interactive Validation Password <form> validation Example

Dynamic Elements Some implementations not associated with web database applications MouseOver Prefilled calculations

MouseOver Creating a mouseOver Event Example

Prefilled Calculations Shopping cart updating Example

Conclusion Javascript is a client-side scripting language Can be used for validating forms and enhancing user interactions Benefits include improved speed, reduced load, and added features

REMEMBER!!!!! NEVER USE AS THE ONLY METHOD TO ENSURE REQUIREMENTS, SECURITY, AND CONSTRAINTS WHY? BECAUSE IT CAN BE BYPASSED BY THE USER

The End