[Zope-dev] z3c.form: Problem validating file uploads

[Michael Howitz]

Am 12.04.2009 um 15:12 schrieb Michael Howitz:
> Hi,
>
> I'm using a trunk version of z3c.form and have the following  
> situation:
> In my interface I have a zope.schema.Bytes field.
> z3c.form.converter.FileUploadDataConverter.toFieldValue returns
> z3c.form.interfaces.NOT_CHANGED when I do not upload a file.
> z3c.form.validator.SimpleFieldValidator.validate fails later on as the
> value (z3c.form.interfaces.NOT_CHANGED) is not of type str (which is
> required by the Bytes field).
> I created a branch in svn to show the behavior. (z3c.form/branches/
> icemac_validate_NOT_CHANGED)
>
> I'm not sure how to fix this generally, some possible solutions come
> to my mind, but each idea has its own problems:
>
> 1) Create a special validator for zope.schema.Bytes +
> z3c.form.interfaces.IFileWidget which knows how to handle NOT_CHANGED.
>    This does not seem to be a really general solution and might have
> the same problems like the following ideas.
>
> 2) When z3c.form.validator.SimpleFieldValidator.validate is called
> with NOT_CHANGED as value, try to look up the value on the context
> object.
>    This fails on AddForms as the context there is the parent object.
>
> 3) When z3c.form.validator.SimpleFieldValidator.validate is called
> with NOT_CHANGED as value, do not validate hoping the previous value
> was valid.
>    This approach fails with AddForms, too, when the Bytes field is
> required. (The missing-value-error does not get raised.)
>
> Anyone having an idea for a possibly working solution?

As I got no responsed, I'd like to put this issue into z3c.form's  
bugtracker. But which is the correct one?
https://bugs.launchpad.net/zope3/ ?

Yours sincerely,
-- 
Michael Howitz · mh at gocept.com · software developer
gocept gmbh & co. kg · forsterstraße 29 · 06112 halle (saale) · germany
http://gocept.com · tel +49 345 1229889 8 · fax +49 345 1229889 1
Zope and Plone consulting and development