CForms: validation error bubbling

[Sylvain Wallez <sy...@apache.org>]

Hi all,

Looking at the paginated repeater patch [1], I again encountered the 
problem of non-displayed widgets that can have validation errors and 
therefore forbid form validation, leading to confusing situations for 
the user.

A general solution for this problem could be to "bubble up" validation 
errors: when the validation error or a widget changes (including when 
it's set to null), the widget notifies its parent of this fact. That can 
allow us to easily implement validation-error gatherers in container 
widgets to display that there's a problem "somewhere" in the container.

For example, in the case of paginated repeater, page numbers or 
scrolling buttons may give visual feedback if errors exist outside of 
the displayed page.

For wizards, we could have group or struct widgets representing each 
page which, by gathering errors raised by their children, would allow to 
display a global validation status of the wizard or drive the user back 
to offending pages.

Thoughts?

Sylvain

[1] http://issues.apache.org/bugzilla/show_bug.cgi?id=30213

-- 
Sylvain Wallez                                  Anyware Technologies
http://www.apache.org/~sylvain           http://www.anyware-tech.com
{ XML, Java, Cocoon, OpenSource }*{ Training, Consulting, Projects }

Re: CForms: validation error bubbling

[Vadim Gritsenko <va...@reverycodes.com>]

Sylvain Wallez wrote:

> Hi all,
> 
> Looking at the paginated repeater patch [1], I again encountered the 
> problem of non-displayed widgets that can have validation errors and 
> therefore forbid form validation, leading to confusing situations for 
> the user.
> 
> A general solution for this problem could be to "bubble up" validation 
> errors: when the validation error or a widget changes (including when 
> it's set to null), the widget notifies its parent of this fact. That can 
> allow us to easily implement validation-error gatherers in container 
> widgets to display that there's a problem "somewhere" in the container.
> 
> For example, in the case of paginated repeater, page numbers or 
> scrolling buttons may give visual feedback if errors exist outside of 
> the displayed page.
> 
> For wizards, we could have group or struct widgets representing each 
> page which, by gathering errors raised by their children, would allow to 
> display a global validation status of the wizard or drive the user back 
> to offending pages.
> 
> Thoughts?

We do have <validation-error> template element. It can be extended, for 
example, by adding attribute recursive="true" or some such, to collect 
all errors from the given container widget. Wouldn't it solve the issue?

Or, we can add new <validation-errors> element to do the same.

Vadim