cocoon-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Sylvain Wallez <>
Subject Re: ValidationAware forms
Date Sun, 05 Jun 2005 17:11:39 GMT
Reinhard Poetz wrote:

> Reinhard Poetz wrote:
>> Sylvain Wallez wrote:
>>> Now there's also the little-known <ft:validation-error> template 
>>> instruction that outputs the validation error or any given widget. 
>>> This can be a good replacement of the message widget, and would 
>>> allow non-visual widgets to be ValidationAware.
>> good idea! I implemented the ValidationErrorAware interface in Form 
>> and Repeater. I fear this will not work in Ajax mode as the errors 
>> are not reported to the client.
> uups, sent this mail to quickly. I wanted to add that I don't have the 
> time to fix this ATM as I would have to dive into the Ajax 
> implementation to find out how to make this possible.

The main principle of the Ajax stuff is that each part of the page that 
can be updated asynchronously (not necessarily a widget) must be fully 
contained in a tag (span, div, input, whatever) with a unique id. In the 
case of widgets, this id is the value of widget.getRequestParameterName().

We therefore need a distinct id for validation errors, which can be e.g. 
{widget.requestParameterName}.$error, which uses the same $-prefix 
convention as Java bytecode for synthetic names (those generated by the 

Update of the validation error is then linked to a change of its 
associated widget. For now, change detection is a boolean thing (changed 
/ unchanged) but we may go to something more fine-grained in the future 
(e.g. value changed / error changed / selection list changed etc).


Sylvain Wallez                        Anyware Technologies  
Apache Software Foundation Member     Research & Technology Director

View raw message