On 2007-06-26 22:41:25 +0200, Gary Poster <[EMAIL PROTECTED]> said:
On Jun 23, 2007, at 6:38 AM, Christian Zagrodnick wrote:
Log message for revision 76975:
FileWidget tries to be smarter about not deleting the currently
stored content when the user did not upload a new file.
...
Modified: zope.app.form/trunk/src/zope/app/form/browser/textwidgets.py
===================================================================
--- zope.app.form/trunk/src/zope/app/form/browser/textwidgets.py
2007-06-23 10:25:23 UTC (rev 76974)
+++ zope.app.form/trunk/src/zope/app/form/browser/textwidgets.py
2007-06-23 10:38:37 UTC (rev 76975)
@@ -475,6 +475,11 @@
def _toFieldValue(self, input):
if input is None or input == '':
+ # There was no input. With File-Upload this usually means
that the
+ # value should *not* change. Let's try to get the old value.
+ content = self.context.context
+ if self.context.interface.providedBy(content):
+ return self.context.get(content)
return self.context.missing_value
try:
seek = input.seek
Hey. This has a couple of bugs, IMO. It might also be a misfeature,
but I'm less sure about that.
First, "return self.context.get(content)" assumes that this widget
will be used on an edit form (not true for us).
Second, "if self.context.interface.providedBy(content):" assumes that
the schema field is part of an interface (not true for us).
Hum. From that I make that there are not enough tests. :/
I figure that the .interface attribute doesn't seem to be part of any
interface anyway. So in fact this is not a nice thing to do.
Neither of these are valid assumptions generally for a form field, IMO.
I'm also not sure about the semantics. Shouldn't this be handled more
at the form level? I can see why you want to do this here, but it
seems pretty gray, and I'm not sure how to solve the bugs in a sane
and reliable way.
No, thinking about it it's not the right way I did it. Basically I
wasn't aware about the different conexts. In general I know that, but
sometimes you're just blind :)
I agree that this is a tricky problem, and it would be nice to solve
it, but your solution is not correct for a generic form widget. The
only suggestion I have ATM is to revert this, unfortunately, but I
welcome other approaches that solve the issues I raised.
Solving it on form level is of course possible but not really the thing
you want to think about. I suspect there should be some 'i have not
changed' marker value.
There is some strange thing in zope.formlib.form.applyChanges
preventing updates of the value already:
def applyChanges(context, form_fields, data, adapters=None):
...
for form_field in form_fields:
...
name = form_field.__name__
newvalue = data.get(name, form_field) # using form_field as marker
if (newvalue is not form_field) and (field.get(adapter) != newvalue):
changed = True
field.set(adapter, newvalue)
return changed
newvalue is not formfield? To me this does not make much sense. Why
would I return self.context to indicate the value has not changed?
Questions over questions :)
--
Christian Zagrodnick
gocept gmbh & co. kg · forsterstrasse 29 · 06112 halle/saale
www.gocept.com · fon. +49 345 12298894 · fax. +49 345 12298891
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