ModelAdmin ignores dynamic fields of ModelForm

[anonymous]

If a ModelForm is created and then modified to programatically add fields (say, in __init__), ModelAdmin ignores these fields when rendering the form. If one of these fields is added to the ModelForm's Meta, the field shows up just fine.

I would expect the field to display without the coaxing in Meta.fields.

1. Create a ModelForm
2. Add it to ModelAdmin
3. View Form
4. Update ModelForm's __init__ to include self.fields['xyz'] = forms.CharField(max_length=255, initial='keke')
5. View Form (note no change)
6. Update ModelForm's Meta.fields to include "xyz"
7. View Form (note the change)

[anonymous]

I've solved this in the meantime by updating contrib/admin/options.py in:

    def get_fieldsets(self, request, obj=None):
        "Hook for specifying fieldsets for the add form."
        if self.declared_fieldsets:
            return self.declared_fieldsets
        #form = self.get_form(request, obj)
        #return [(None, {'fields': form.base_fields.keys()})]
        form = self.get_form(request, obj)(instance=obj)
        return [(None, {'fields': form.fields.keys()})]

Seems to be a harmless fix, possible to get this applied upstream?

[Ramiro Morales]

(reformat description, also it hasn't a patch until it has a patch)

[Batiste Bieler]

I think the declared_fieldsets too satic too. Why not using a callable that people can override?

I can provide a patch if needed.

[Batiste Bieler]

Attempt to use dynamic fieldsets generation

[Batiste Bieler]

The patch I sent seems to work quite oki, but if I add a field dynamicaly, even if it's in the form object, the new value is not saved:

    def dynamic_fieldsets(self, request, obj=None, **kwargs):

        general_fields = list(self.general_fields)
        perms = PagePermission(request.user)

        if perms.check('freeze'):
            general_fields.append('freeze_date')

        return [
            [_('General'), {
                'fields': general_fields,
                'classes': ('module-general',),
            }],
            (_('Options'), {
                'fields': self.normal_fields,
                'classes': ('module-options',),
            }),
        ]

My freeze field is added properly in the admin interface, but the value is not saved. But in the other hand if I do things like that:

    def get_fieldsets(self, request, obj=None):
        """
        Add fieldsets of placeholders to the list of already
        existing fieldsets.
        """
        general_fields = list(self.general_fields)
        perms = PagePermission(request.user)

        # some ugly business to remove freeze_date
        # from the field list
        general_module = {
            'fields': list(self.general_fields),
            'classes': ('module-general',),
        }

        default_fieldsets = list(self.fieldsets)
        if not perms.check('freeze'):
            general_module['fields'].remove('freeze_date')

        default_fieldsets[0][1] = general_module

The latest version works, but it feels like a very hackish way to do things.

Can somebody explain me what's wrong here? Does Django have a more elegant way to do this?

[anonymous]

@anonymous 6.Update ModelForm's Meta.fields to include "xyz" - howto? my Meta has no attr 'fields' while runtime in init
I have the same problem - trying to add dynamic field to ModelForm

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[François Freitag]

6. Update ModelForm's Meta.fields to include "xyz"

This step leaves the Meta.fields modified, because the Meta is only instantiated when the ModelForm class is constructed. Thus, on the next request, "xyz" will still be part of the Meta.fields. In my use case, the field was added conditionally, and was unexpectedly present in the Meta.fields on the next request.

This might be a pitfall for others.