[EMAIL PROTECTED] wrote on 31/10/2005 06.12.43:
> Just added this to FAQ (http://zissue.berlios.de/z3/z3faq.html). > I expects more contribution in coming months. > > > How to validate two or more fields simultaneously? > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Use `invariants` to control more fields. > > Look at zope.interface/README.txt for details. > > Let's consider this more specific question asked to list: > > How do I implement a validation rule that says either email or phone > have to exist, but not necissarily both. > > Using the buddy demo as an example, with the following interface:: > > class IBuddy(zope.interface.Interface): > """Provides access to basic buddy information""" > > fullname = TextLine(title=_("Name")) > email = TextLine(title=_("Email Address")) > phone = TextLine(title=_("Phone Contact")) > > First we have to make a callable object, either a simple function or > callable instance of a class:: > > def contacts_invariant(obj): > if not (obj.email or obj.phone): > raise Exception("At least one contact info is rquired") > > Now use `validateInvariants` method of the interface to validate:: > > buddy = Buddy() > buddy.email = u"[EMAIL PROTECTED]" > IBuddy.validateInvariants(buddy) What I would want to be further explained is: When should I call validateInvariants? Of course I would call it when I'm creating or editing the object. Then, frequently, just after an add or edit form. More: can I then use auto generated forms (by using events after the form, but how?), or I just have do define a custom form? And then: what do I do if the validation falils? How do I return the form, possibly with an error message? I feel these are genuine FAQs, and I still don't have answers for many of them. Working through them at a steday pace, though ;) Thanks for all your help, really. ciao Guido _______________________________________________ Zope3-users mailing list Zope3-users@zope.org http://mail.zope.org/mailman/listinfo/zope3-users
