Re: [Zope3-Users] z3c.form: LookupErrors
Stephan Richter wrote: On Wednesday 08 April 2009, Martin Aspeli wrote: What I'd like to see: 1) z3c.form catches the LookupError and treats it as a valdiation error (even on first render of the form), not a fatal error 2) z3c.form defaults to missing_value if there is a LookupError against what the data manager returns. The value is indeed missing in action 3) If possible, we output the offending value in the error message 4) In use cases where it makes sense, people can use a field property implementation that checks the source and returns the default (or something else) if the value can't be found. That's not for z3c.form to decide or depend on though. Sounds good. Would you mind making a 1.9 maintenance branch and, if we fix a few bugs, could you release 1.9.1 soonishly. Martin -- Author of `Professional Plone Development`, a book for developers who want to work with Plone. See http://martinaspeli.net/plone-book ___ Zope3-users mailing list Zope3-users@zope.org http://mail.zope.org/mailman/listinfo/zope3-users
[Zope3-Users] z3c.form: LookupErrors
Hi, In z3c.form (at least with 1.9.0), if you have a Choice field and the vocabulary changes so that an existing value (or the default value on an add form) is no longer valid, you get a LookupError: Module z3c.form.form, line 126, in updateWidgets Module z3c.form.field, line 259, in update Module z3c.form.browser.select, line 51, in update Module z3c.form.browser.widget, line 61, in update Module z3c.form.widget, line 182, in update Module z3c.form.widget, line 120, in update Module z3c.form.converter, line 258, in toWidgetValue Module z3c.form.term, line 31, in getTerm Module zope.schema.vocabulary, line 124, in getTerm It'd be nicer if z3c.form would catch the error and return field.missing_value or something like that. As it stands, if this happens with a content object, it's impossible to reach the edit form and fix the value! Martin -- Author of `Professional Plone Development`, a book for developers who want to work with Plone. See http://martinaspeli.net/plone-book ___ Zope3-users mailing list Zope3-users@zope.org http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] z3c.form: LookupErrors
Hi Martin -Ursprüngliche Nachricht- Von: zope3-users-boun...@zope.org [mailto:zope3-users-boun...@zope.org] Im Auftrag von Martin Aspeli Gesendet: Dienstag, 7. April 2009 16:17 An: zope3-users@zope.org Betreff: [Zope3-Users] z3c.form: LookupErrors Hi, In z3c.form (at least with 1.9.0), if you have a Choice field and the vocabulary changes so that an existing value (or the default value on an add form) is no longer valid, you get a LookupError: Module z3c.form.form, line 126, in updateWidgets Module z3c.form.field, line 259, in update Module z3c.form.browser.select, line 51, in update Module z3c.form.browser.widget, line 61, in update Module z3c.form.widget, line 182, in update Module z3c.form.widget, line 120, in update Module z3c.form.converter, line 258, in toWidgetValue Module z3c.form.term, line 31, in getTerm Module zope.schema.vocabulary, line 124, in getTerm It'd be nicer if z3c.form would catch the error and return field.missing_value or something like that. As it stands, if this happens with a content object, it's impossible to reach the edit form and fix the value! This is a legacy data problem. Such data need to get migrated by a generation if a value is no longer valid. Otherwise the wrong (not valid) value is still used in the app. It doesn't make sense to just skip invalid values and fallback to missing_value in the vocabulary widget since this value get used by everthing else then the widget. But probably if legacy data are not a problem in some apps, we should implement a vocabulary and widget which can handle such legacy data problems or make it a configurable option. I also was thinking about a widget which allows to define depreated values which are valid but not shown for selecting. this whould allow to skip values fer a future selection. Probably this whould require a enhanced vocabulary implementation which offers a deprecated value list or something like that. What do you think? Whould this fit for you? Regards Roger Ineichen Martin -- Author of `Professional Plone Development`, a book for developers who want to work with Plone. See http://martinaspeli.net/plone-book ___ Zope3-users mailing list Zope3-users@zope.org http://mail.zope.org/mailman/listinfo/zope3-users ___ Zope3-users mailing list Zope3-users@zope.org http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] z3c.form: LookupErrors
On Tuesday 07 April 2009, Roger Ineichen wrote: It'd be nicer if z3c.form would catch the error and return field.missing_value or something like that. As it stands, if this happens with a content object, it's impossible to reach the edit form and fix the value! This is a legacy data problem. Such data need to get migrated by a generation if a value is no longer valid. No, it is not. The legacy data problem is a special case. What if your list of choices depends on constantly changing data? For example, a widget allows you to select a user from a userfolder. Later the user gets deleted. Just because you selected the user before, the form should not fail. I totally agree with Martin that we should use missing_value in those cases. I think this could actually be considered a fairly serious bug. Regards, Stephan -- Stephan Richter Web Software Design, Development and Training Google me. Zope Stephan Richter ___ Zope3-users mailing list Zope3-users@zope.org http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] z3c.form: LookupErrors
Hi Stephan -Ursprüngliche Nachricht- Von: Stephan Richter [mailto:srich...@cosmos.phy.tufts.edu] Gesendet: Dienstag, 7. April 2009 19:30 An: zope3-users@zope.org; d...@projekt01.ch Cc: 'Martin Aspeli' Betreff: Re: [Zope3-Users] z3c.form: LookupErrors On Tuesday 07 April 2009, Roger Ineichen wrote: It'd be nicer if z3c.form would catch the error and return field.missing_value or something like that. As it stands, if this happens with a content object, it's impossible to reach the edit form and fix the value! This is a legacy data problem. Such data need to get migrated by a generation if a value is no longer valid. No, it is not. The legacy data problem is a special case. What if your list of choices depends on constantly changing data? For example, a widget allows you to select a user from a userfolder. Later the user gets deleted. pang, legacy data created Just because you selected the user before, the form should not fail. and the question is, do you cleanup legacy data or not I totally agree with Martin that we should use missing_value in those cases. Defently not. Such forms will show you a default value and you think this is Ok. But the object devliers still the old stored value. Pang, pang and you will be surprised till you will start debugging and see the real value decorated within the missing_value. That's a horrible scenario! I think this could actually be considered a fairly serious bug. No, defently not, the Choice field defines what are valid values and the widget only handels that. There is no reason why a widget should do more then that. If you remove valid values for a field, you also have to make sure that the system doesn't use them. Doesn't matter if a system can work with different/legacy data or not. I think you are right that a valid missing_value should get used, but that must be implemented at the field level. The field has to return that missing_value. This will make sure that objects value returns the same as the widget does. But that's a kind of auto-mirgation for legacy data. And I'm not sure if this is a good idea. Regards Roger Ineichen Regards, Stephan -- Stephan Richter Web Software Design, Development and Training Google me. Zope Stephan Richter ___ Zope3-users mailing list Zope3-users@zope.org http://mail.zope.org/mailman/listinfo/zope3-users
