Re: [Zope-dev] z3c.form: data manager for PersistentDict/PersistentMapping
Am 13.07.2009 um 16:49 schrieb Stephan Richter: > On Saturday 11 July 2009, Michael Howitz wrote: >> z3c.form.datamanager.DictionaryField is a data manager which is >> registered for fields on a dict. In its __init__ it checks whether >> the >> data object is an instance of dict. So this data manager does neither >> work for UserDict nor PersistentDict/PersistentMapping. >> I'd like to change this but there are two possibilities and I'm not >> sure which is the best one: >> >> 1.) Add a subclasses of DictionaryField which is registered for >> UserDict and which checks whether the data object is an instance of >> UserDict. >> (PersistentDict and PersistentMapping are subclasses of >> UserDict.) >> >> 2.) Register DictionaryField for >> zope.interface.common.mapping.IMapping. This might have a problem as >> neither UserDict nor PersistentDict/PersistentMapping seem to provide >> this interface. (Why?) > > I looked at this recently and the reason is that for containers we > did not > usually want the dictionary field data manager, because we usually > want the > regular instance based one. > > I am okay to add PersistentDict and PersistentMapping to the list. I > am > already feeling unsure about UserDict, because people might want the > instance > version instead. It is better to register the adapter for the > specific cases of > your application. I'm fine with that, so I'm going to allow PersistentDict and PersistentMapping in the constructor of DictionaryField and I'll add an note why the adapter is only registered for dict and not for the other possible data storages. Yours sincerely, -- Michael Howitz · m...@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 ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] z3c.form: data manager for PersistentDict/PersistentMapping
On Saturday 11 July 2009, Michael Howitz wrote: > z3c.form.datamanager.DictionaryField is a data manager which is > registered for fields on a dict. In its __init__ it checks whether the > data object is an instance of dict. So this data manager does neither > work for UserDict nor PersistentDict/PersistentMapping. > I'd like to change this but there are two possibilities and I'm not > sure which is the best one: > > 1.) Add a subclasses of DictionaryField which is registered for > UserDict and which checks whether the data object is an instance of > UserDict. > (PersistentDict and PersistentMapping are subclasses of UserDict.) > > 2.) Register DictionaryField for > zope.interface.common.mapping.IMapping. This might have a problem as > neither UserDict nor PersistentDict/PersistentMapping seem to provide > this interface. (Why?) I looked at this recently and the reason is that for containers we did not usually want the dictionary field data manager, because we usually want the regular instance based one. I am okay to add PersistentDict and PersistentMapping to the list. I am already feeling unsure about UserDict, because people might want the instance version instead. It is better to register the adapter for the specific cases of your application. Regards, Stephan -- Entrepreneur and Software Geek Google me. "Zope Stephan Richter" ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] z3c.form: data manager for PersistentDict/PersistentMapping
Am 11.07.2009 um 17:43 schrieb Michael Howitz: > Hello, > > z3c.form.datamanager.DictionaryField is a data manager which is > registered for fields on a dict. In its __init__ it checks whether the > data object is an instance of dict. So this data manager does neither > work for UserDict nor PersistentDict/PersistentMapping. > I'd like to change this but there are two possibilities and I'm not > sure which is the best one: > > 1.) Add a subclasses of DictionaryField which is registered for > UserDict and which checks whether the data object is an instance of > UserDict. > (PersistentDict and PersistentMapping are subclasses of UserDict.) > > 2.) Register DictionaryField for > zope.interface.common.mapping.IMapping. This might have a problem as > neither UserDict nor PersistentDict/PersistentMapping seem to provide > this interface. (Why?) Replying to myself, as I saw on the z3c.form trunk that DictionaryField already allows providers of zope.interface.common.mapping.IMapping additionally to dict instances as the storage object. The existing solution uses the second of my possibilities, but this is not the one which I'd like to prefer, as it does not work with PersistentMapping out of the box. The idea behind this change on the trunk seems to be: to allow SessionPkgData as storage. I currently do not use it directly but use a PersistentMapping inside SessionPkgData. But maybe this is a sufficient solution for now. Yours sincerely, -- Michael Howitz · m...@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 ___ Zope-Dev maillist - Zope-Dev@zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )