[Zope-dev] zope.app.form: Make "no value" always available?

[Roger Ineichen]

Hi Thomas
 
> Betreff: [Zope-dev] zope.app.form: Make "no value" always available?
> 
> zope.app.form items edit widgets don't provide the "no value" 
> value if the corresponding field is required. While this 
> prevents invalid input, it means that e.g. a drop-down box 
> may then have one of the valid values pre-selected. If user 
> forgets to change that value, he could save the form without 
> noticing that the default value is implicitly selected, which 
> may be completely wrong.
> 
> In some cases it would be preferrable for the widget to 
> default to a "no value" value even if the field is required 
> so the form won't validate if the user doesn't consciously 
> select a value. One of our customers asked for this 
> behaviour, for example. If noone objects, we'd like to change 
> zope.app.form accordingly.

I agree with this but...
The 2750 test in one of our well tested application will explode.
And probably some tests in the zope core and z3c will break too.

Since this is a miss behavior and I agree that this should get 
fixed. We probably should think about a solution which supports
the old behavior by default.

Note, this whould probably also break other packages like 
z3c.csvvocabulary.

If nobody else objects I'm fine with this changes and will fix a 
Zope3 revision for this project and start to migrate to z3c.form.
We have to do that anyway sometimes.

In general, this is not a bug it's just a bad behavior.

What do you think?

Regards
Roger Ineichen

> --
> Thomas Lotze · tl at gocept.com
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> · germany http://gocept.com · tel +49 345 1229889 0 · fax +49 
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