[html-formfu] Clientside validation

[Andreas Marienborg]

On Mar 5, 2008, at 12:11 PM, Carl Franks wrote:

> On 05/03/2008, Andreas Marienborg <omega at palle.net> wrote:
>>
>> On Mar 5, 2008, at 10:54 AM, Carl Franks wrote:
>>
>>> On 05/03/2008, Andreas Marienborg <omega at palle.net> wrote:
>>>> Has anyone done any clientside validation with FormFu? Basicly I  
>>>> want
>>>> to only specify constraints etc once, in the FormFu-config, and  
>>>> then
>>>> just have it magicaly work on the forms in the web app, or atleast
>>>> provide me with the information needed to do the client side stuff
>>>> (like what constraints are on a field etc).
>>>>
>>>> If that is not possible, is it possible to process only "part" of a
>>>> form? So I can call back to the server to check each field as they
>>>> are
>>>> filled out?
>>>>
>>>>
>>>> If anyone has any thoughts on any of this, I would be glad to  
>>>> hear it
>>>
>>> I put this JS demo together about a year ago.
>>> http://www.fireartist.com/tmp/client-side-constraint.html
>>>
>>> It supports filters & constraints and uses the same error markup  
>>> that
>>> server-side validation would generate.
>>>
>>> At the moment, it uses an old version of dojo.
>>> It would probably be best to have the more advanced functionality
>>> (such as class name changes) isolated in core functions, and allow
>>> them to be implemented in different frameworks - and have the
>>> individual constraints, filters, etc only use standard JS.
>>> Although, if someone's willing to write the necessary functions in
>>> cross-browser JS so that we don't need an external library, that  
>>> would
>>> be great.
>>>
>>> I created the branch /branches/auto-js for this, but have never
>>> checked the changes in, so I'll probably need to start from  
>>> scratch as
>>> the internals have changed so much since the branch was made.
>>>
>>> I imagine it being implemented such that you can switch it on with
>>> something like:
>>>
>>>   clientside_validation: 1
>>>   clientside_library: 'Dojo'
>>
>>
>> That sounds ideal. I would whip up a MochiKit implementation asap :p
>>
>> However, is it possible to easily manipulate what is outputed, so as
>> to add information about constraints etc to the markup?
>
> What exactly are you thinking of?
>
> It's already possible to set classnames to include the constraint type
> - see "%t" in
> http://search.cpan.org/~cfranks/HTML-FormFu-0.02004/lib/HTML/FormFu.pm#auto_constraint_class
>
> The way the demo works is: it adds the concepts of 'forced' errors.
> The spans for forced-errors have a different classname and are  
> hidden using CSS.
> JS is used to put the error messages into the spans, so that users
> without JS/CSS don't see the error message at all.
> (If you've got JS switched on, but CSS turned off, then you'll see the
> messages, but then it's a rather unlikely combination.
>
> When the constraints are run, the classname is changed, so that the
> appropriate message is either hidden or displayed.
>
> Carl

Aha, pretty smooth :p Guess I should take the time to read more docs


- andreas