On Jul 31, 7:37 pm, Malcolm Tredinnick <[email protected]> wrote: > On Fri, 2009-07-31 at 16:31 -0700,mviamariwrote: > > Hello, > > > I'm trying to make a form for data entry into my database that uses > > ChoiceFields for foreign keys. Obviously, the ideal choice would be > > ModelChoiceField, however I'm not using the django ORM, so I've > > assumed that's not going to work (I'm using Elixir/SQLAlchemy). > > > I originally set the choices parameter in the ChoiceField declaration > > to be derived from a query result from SQLAlchemy (returned as an > > array of tuples). The problem is that the choices don't update when > > the database changes. They are fixed to whatever was present when the > > server is initialized (or at least it appears to be). > > If you have specified the choices field as a parameter to a Field > subclass in a Form class, then it will be evaluated whenever that Form > class is parsed (probably at import time). That's normal Python > behaviour. > > > I'm looking for suggestions/advice on to get the ChoiceField choices > > to update when the form is the used. > > "Used" is probably a bit ambiguous here. It's probably easier to think > in terms of "when an instance of the form class is created." The > solution is to update the choices attribute on the appropriate field in > the Form subclass's __init__() method. For example > > class MyForm(forms.Form): > options = forms.ChoiceField() > > def __init__(self, *args, **kwargs): > super(MyForm, self).__init__(*args, **kwargs) > choices = ... # <-- create a sequence of 2-tuples > self.fields["options"].choices = choices > > You can do whatever you like to populate the "choices" variable in the > above fragment. The only requirement is that you end up with a sequence > of pairs which are the submitted form value and the human readable text > for the form element. > > Regards, > Malcolm
Thanks Malcom. That appears to have worked. Mike --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
