Admin list_editable and ForeignKeys: Applying widget attributes with specific forms lead to strange off-by-one effects

[Amir Hadi]

We want to make some foreign key fields in the Admin list_editable. Also we want to add some widget attributes to the field, i.e. the instance PK for each row, a disabled tag and so on.

When we use the following code snippet, we see that the first row does not get the widget attributes applied. Strangely the second row contains the instance PK of the first row, the third row contains the PK of the second and so on. The effects on the interface can be seen here ​http://s22.postimg.org/lk8kxa4ch/Screen_Shot_2016_02_12_at_10_25_25.png

class LeadAdminForm(forms.ModelForm):
    class Meta:
        model = Lead
        fields = ['user_reference', 'state']

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['user_reference'].widget.attrs['data-lead-id'] = self.instance.pk
        self.fields['state'].widget.attrs['data-lead-id'] = self.instance.pk
        self.fields['user_reference'].widget.attrs['disabled'] = 'disabled'
        self.fields['state'].widget.attrs['disabled'] = 'disabled'


class LeadAdmin(admin.ModelAdmin):
    list_display = ['id', 'user_reference', 'state']
    list_editable = ['user_reference', 'state']
    list_per_page = 3

    def get_changelist_form(self, request, **kwargs):
        return LeadAdminForm

    def changelist_view(self, request, extra_context=None):
        extra_context = extra_context or {}
        #extra_context['params'] = get_connection_parameters(request.user)
        return super().changelist_view(request, extra_context)

We tested this with Django 1.8.9 and Django 1.9.2. I have also attached a demo project. Unfortunately we could not find the issue in the code.

[Amir Hadi]

Demo Project to show the issue

[Tim Graham]

Thanks for the sample project. It looks to me like you need to target the inner widget of RelatedFieldWidgetWrapper, e.g. self.fields['user_reference'].widget.widget.attrs['disabled'] = 'disabled'. The fact that the original line works (except in the first row) appears to be a manifestation of #12134. With the patch from that ticket, the original line won't work at all.

[Amir Hadi]

Replying to timgraham:

Thanks for the sample project. It looks to me like you need to target the inner widget of RelatedFieldWidgetWrapper, e.g. self.fields['user_reference'].widget.widget.attrs['disabled'] = 'disabled'. The fact that the original line works (except in the first row) appears to be a manifestation of #12134. With the patch from that ticket, the original line won't work at all.

Okay that seems to work. Thank you very much.