[html-formfu] FormFu + Ajax

[Roberto Baglioni]

Yes, it helps indeed! thanks a lot!

ciao
Roberto Baglioni


On 27/nov/08, at 14:45, Carl Franks wrote:

> 2008/11/27 Roberto Baglioni <baglioni at arcetri.astro.it>:
>> Hi,
>> I'm starting using FormFu and I have found a problem I don't know  
>> how to
>> handle.
>>
>> I use Ajax to populate a Select field. When the user submits the
>> form, FormFu checks the input, and if it finds some errors the form  
>> is
>> displayed again for further input. The problem is that in this  
>> operation
>> the items in the list, populated by Ajax and possibly the value  
>> selected
>> by the user, got lost.
>> Is there any mean to notify FormFu that the form is changed, or do  
>> you
>> suggest
>> other means to overcome the problem?
>
> Hi Roberto,
>
> There's 2 problems here.
> The first is that because the Select's list of options isn't sent by
> the browser, FormFu thinks the select has no option list.
> The other is that when FormFu is re-rendering the form, because the
> Select field has no list of options, nothing is marked as "selected",
> so the submitted value is lost.
>
> I can think of 2 ways around the first problem.
>
> When the page is redisplayed after errors, I would use AJAX again to
> re-populate the Select field's list of options - the same way you did
> initially.
> You'll also need to add a Hidden field, with a CopyValue Filter on it,
> so that when the Select value is submitted to FormFu, that value also
> gets copied to the hidden field.
> Then, when the page is redisplayed after errors, use JavaScript to
> check for the presence of that hidden field's value, and use it to set
> the "selected" value of the select field.
>
> The alternative would be when you're first populating the Select list
> with AJAX, also stuff the list into a hidden field (maybe as
> serialized JSON), so it will be sent back to FormFu.
> Then use server-side code to parse that hidden field's value, and
> recreate the Select field's option list.
> Then, when you're redisplaying the form, the Select field should
> automatically get the correct "selected" item set.
>
> Hope this helps,
> Carl
>
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