[ZCM] [ZC] 2126/ 2 Reject "Mystery of WrongContainedType"

[Collector: Zope Bugs, Features, and Patches ...]

Issue #2126 Update (Reject) "Mystery of WrongContainedType"
 Status Rejected, Zope/bug low
To followup, visit:
  http://www.zope.org/Collectors/Zope/2126

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= Reject - Entry #2 by ajung on Jun 7, 2006 1:06 pm

 Status: Pending => Rejected

Please use the Zope 3 collector for Zope 3 related issues.
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= Request - Entry #1 by rnd0000 on Jun 7, 2006 1:01 pm

Module zope.app.form.utility, line 307, in applyWidgetsChanges

    WidgetsError: WrongContainedType: [] 

- the invisible value of the list is some auxiliary stub for required_parameter_missing. However, its probably not proper behaviour: error needs to be shown OR there must be some other error (the error is not critical but can cause problems when required parameter (of a schema) like List is missing...

The error could be reproduced when the schema has "required" List field, but in the beginning doesn't have any values in it. So, automatically generated widgets fails, giving the error WrongContainedType with (seemingly) empty list, however, the list is not empty - it has a "RequiredMissing" or something like that, which causes confusion as it doesn't give any hints on the error nature.

Silently ignoring exceptions in applyWidgetChanges() is working, but it is not good workaround... 

The error could hit badly when some parameter become "required" in the later version of schema, whereas old versions had empty lists.

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