Hi Matthias , Thank you, I went for option 1 and it works perfectly!
Funny, the add_to_class function basically does "setattr(cls, name, value)". So I had the right solution, only you have to do this after class creation, not inside its __init__ function. Good to know, will blog about this :) Again, thank you very much. Cheers, Kevin On Nov 26, 10:14 am, Matthias Kestenholz <matthias.kestenh...@gmail.com> wrote: > On Thu, Nov 26, 2009 at 9:56 AM, Kevin Renskers <i...@bolhoed.net> wrote: > > Just a small update: the DynamicModels way as described on the wiki > > doesn't work (it also says that it only works in Django 0.96, so > > yeah..). > > > If anyone has any idea how to do this, I would be very thankful! > > > On Nov 24, 2:35 pm, Kevin Renskers <i...@bolhoed.net> wrote: > >> Hi all, > > >> In my Django project I want to have a model that is dynamically > >> created. I tried using the __init__ function for this, something like > >> so: > > >> fields = ['field_a', 'field_b', 'field_c'] > > >> class MyModel(models.Model): > >> def __init__(self, *args, **kwargs): > >> for field in fields: > >> setattr(self, field, models.DecimalField(decimal_places=4, > >> max_digits=10)) > > >> Sadly, this doesn't work. The columns don't get created when you run > >> the syncdb command, and even something like > >> MyModel._meta.get_all_field_names() doesn't return the dynamic fields. > > >> So, is there a way I can create a "dynamic" model? I did come > >> acrosshttp://code.djangoproject.com/wiki/DynamicModelsbutI don't really > >> get that. It looks so much different then normal models, it seems like > >> I would loose a lot of functionality or would have to change a lot of > >> code somewhere else in my application? > > >> Hopefully there is an easy way to do this :) > > I can see two ways to achieve what you seem to want: > > 1. Add fields after the model has been created > > This method uses an only unofficially documented feature[1] of > Django's model field classes. > > class MyModel(models.Model): > # a few fields > > for field in fields: > MyModel.add_to_class(field, models.DecimalField(decimal_places=4, > max_digits=10)) > > 2. Construct a new type dynamically > > class Meta: > verbose_name = _('my model') > > attrs = { > '__module__': 'mymodule', > 'Meta': Meta, > 'method1': method1, > # ... more fields and methods > > } > > for field in fields: > attrs[field] = models.DecimalField(...) > > MyModel = type('MyModel', (models.Model,), attrs) > > Of course, the usual caveats apply. It might make your code harder to > read and understand, and harder to debug too, because it is not clear > what model fields exist by simply looking at the model code (that > applies especially to method 1) > > Matthias > > [1]: It's documented in Marty Alchin's excellent Pro Django book. I > think we can assume that this method won't go away without very good > reasons(tm). -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-us...@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
