[imps] Forms Constraint Validation : validationMessage

[Ian Hickson]

On Fri, 12 Mar 2010, Mounir Lamouri wrote:
> 
> The specs say, when the element is candidate for constraint validation 
> and doesn't satisfy its constraints, the validationMessage 'must return 
> a suitably localized message that the user agent would show the user 
> [...]' and when the element suffers form a custom error it should be the 
> return value.
> 
> As I understand it, that means :
> if (IsCandidateForConstraintValidation())
> {
>   if (!IsValid())
>   {
>     if (IsSufferingFromCustomMessage())
>       ShowCustomMessage();
>     else
>       ShowMessage();
>   }
> }
> 
> But the 'ShowMessage()' is not clearly defined. If the element is 
> suffering from more than one error, according to the specs, if one of 
> them is custom error, the function should return the custom error string 
> but if the element is suffering from more than one error and none of 
> them is the custom error what should be the error string ?
> 
> I think UA are going to return a message that will correspond to only 
> one of the constraint errors, classifying themselves the errors. As far 
> as I can tell Webkit is doing that. So, should the specifications set a 
> prioritized list of errors to return or should it be UA specific ?

It's basically up to the user agent. I suppose we could set a priority 
list, but I don't think it necessarily really would help authors much. 
This is the kind of thing for which implementation experience (once 
authors start using it) would be quite useful for, though.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'