Am 18.08.2011 um 09:59 schrieb Joshua Immanuel: > Hello all, > > I use the zope.schema field's constraint parameter to check for the > uniqueness of a particular field like this > > class IMyObject(Interface): > > def check_for_uniqueness(value): > cat = getUtility(ICatalog) > results = cat.searchResults(object_name=value) > for rslt in results: > if rslt.name.lower() == value.lower(): > raise NameAlreadyExists(value) > return True > > name = TextLine(title=u'Name', required=True, > constraint=check_for_uniqueness) > ... > > This goes well with the zope.formlib's AddForm.
As the value does not exist yet. > But in edit form if I > modify any other field other than the 'name' field I get the > 'NameAlreadyExists' error. As you find the object which you are editing in the catalog. > Worse case scenario is where I have a cancel > action button which just redirects to another page, that too screams for > the NameAlreadyExists error. > > Is there a way to disable the constraint check in the EditForm if the > 'name' field isn't modified? Make sure your catalog search does not return the object you are currently editing. > What is the preferred way of doing these kind of checks? Some time a ago I wrote a blog post about objects with attributes which are unique in their container [1]. Besides it is written in German you might get the clue from the code examples. [1] http://blog.gocept.com/zope3-objekte-mit-eindeutigen-titeln-innerhalb-eines-ordners Mit freundlichen Grüßen -- Michael Howitz · m...@gocept.com · Softwareentwickler gocept gmbh & co. kg · Forsterstraße 29 · 06112 Halle (Saale) · Deutschland http://gocept.com · Tel +49 345 1229889 8 · Fax +49 345 1229889 1 Zope- und Plone-Beratung und -Entwicklung _______________________________________________ Zope-Dev maillist - Zope-Dev@zope.org https://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - https://mail.zope.org/mailman/listinfo/zope-announce https://mail.zope.org/mailman/listinfo/zope )
