1. Client-Side Validation with Javascriptby
Daniel Yee

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

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

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

5. 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”>

6. 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

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

8. Batch Error Reporting Validation for multiple fields
Example

9. Interactive Validation
Password <form> validation
Example

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

11. MouseOver
Creating a mouseOver Event
Example

12. Prefilled Calculations
Shopping cart updating
Example

13. 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

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

15. The End