Changing validation rules on the fly

[altunyurt]

I'm trying to update the validation rules of some fields that depend on the values of others on the fly, with no success. Sample code is at http://jsfiddle.net/2vfaV/3/ "deneme" is the main field and validation of "bagimli" depends on the value of deneme. How can i update the validation rule of bagimli?

[ericmbarnard]

@altunyurt

I believe this is happening because ko.validation is not over-writing your previously added rule, and instead is adding an additional 'required' rule. Also, the required rule hasn't really been tested with a false setting, as ko.validation is not really designed for changing rules on the fly.

For now you can probably workaround the issue by doing something like this: http://jsfiddle.net/2vfaV/7/

But, like I said... required isn't really expecting to have a 'false' value.

One other option you have is to do .extend({ validatable: false }); ... that will erase all validation from the observable, and then you can - re-assign validation to it. The only problem here is that you would have to call ko.applyBindings again.

[altunyurt]

@ericmbarnard thanks for the example. I've tried the validatable after posting the question with no success, yet i wasn't aware of rebinding.

[carlschroedl]

@altunyurt ,

I've applied some functionality from ValidatedViewModel to your example:

http://jsfiddle.net/carlschroedl/d9Mzv/

Does this behave how you expect?