Examples of usage of JSF

Question

Are their any good websites (characterized by high usage), that use JSF for their back-end? I have just started working with the basics of the framework. If I see some websites using JSF, may be I will be able to better appreciate the use of the technology.

Also could you mention the benefits of using JSF validation viz a viz the browser side validation of content using JavaScript.

Answer 1

See here for a list of JSF sites.

In addition see the references for two famous JSF component frameworks:

• Richfaces
• Icefaces

As for the validation - it better be on both sides - on the client side (javascript) for better usability, and on the server side for better security.

Answer 2

On the validation questions:

Server side Advantages:

• Most common validation rules can be declaratively specified i.e. validation rules are specified in tag attributes. Since there is very little code written, this is highly maintainable
• For the rest of the validation rules, one can write custom Validator implementations. These implementations (unlike custom components) are straight forward. Although they are more work than declarative validation, but still more maintainable than the JavaScript approach.

Server side Dis-advantages:

• Usability is the biggest issue here. Any validation failures can be reported only when the complete HTML form is submitted (not when the value is keyed in). In JSF 2.0 this downside can be overcome by making ajax calls to your validation logic and reporting failures as values are keyed in

JavaScript Advantages

• Usability - as detailed above - can report failures as values are keyed in

JavaScript Disadvantages

• Even with JS libraries like jQuery, it can be pretty difficult to implement and maintain js code that supports all browsers. Adding support to a new browser can be very expensive.
• All data required to complete validation must be pre-loaded when the response is rendered. Whereas in the server side approach the validation code can lookup any data it needs.