Question

I have a complex form with some fields that are generated on the fly using JS/jQuery.

The problem with this generation on the fly is the complexity to validate this fields on the server side. I don’t know if I should store the generated forms and values generated by the JS and try to validade on the server side or by other hand use another approach like validate all on the client side(easier I think).

• My question 1 is: It is possible to do all validations using JS? There is some JS validation framework that will help me on this task? I’ve goggled and have found LiveValidation(www.livevalidation.com), is this what I need?

• Question 2: What problems I will have using this kind of approach(validata all on the client side)?

Some clues, thoughts?

Best Regards,

Answer 1

André, we do that all the time. Javascript validation is a key point and has to be performed before a submit occurs, the main reason being

• to make the site / page user friendly
• not to actually check, verify, fix the data before it is sent to the server, since the JS validation can be easily bypassed (so there should always be another round of checking server side), thanks to Firebug, Chrome… and a bunch of command line tools.

You use JS validation to, for instance

• ensure the user filled all mandatory fields, and point to the missing field (focus)
• check the type of the data entered, and warn user
• ensure fields consistency (card number, birthdate, fieldX with fieldY…)
• …

Besides, to answer your last question, and to paraphrase the beginning of the answer (doesn’t hurt)

• JS validation does not ensure the data sent to the server is clean / solid / consistent (it cannot as JS validation can easily be bypassed)
• the server has to perform the same validation – or stronger – on all fields, and never trust the user input (SQL injection risks etc…).