id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
27240	Docs - Passing custom parameters to formset forms in admin	Alexey Rogachev	nobody	"I have `Enterprise` model and related model `Attachment`. Attachments are managed using formsets in both frontend and backend.

I use custom form to handle attachments, and it uses additional `user` kwarg:

{{{#!python
def __init__(self, *args, **kwargs):
    self.user = kwargs.pop('user', None)
    super(AttachmentForm, self).__init__(*args, **kwargs)
}}}

I need to fill this parameter with `request.user` value. In frontend I use the method recommended in [https://docs.djangoproject.com/en/1.9/topics/forms/formsets/#passing-custom-parameters-to-formset-forms docs] (code omitted for brevity).

{{{#!python
enterprise = Enterprise()
AttachmentFormSet = generic_inlineformset_factory(Attachment, form=AttachmentForm, max_num=3, validate_max=True)
if request.method == 'POST':
    attachment_formset = AttachmentFormSet(request.POST, request.FILES, instance=enterprise, form_kwargs = {'user': request.user})
else:
    attachment_formset = AttachmentFormSet(instance=enterprise, form_kwargs = {'user': request.user})
}}}

But docs do not cover how achieve the same thing in backend using Django Admin.

In admin I have:

{{{#!python
class AttachmentInline(GenericTabularInline):
    model = Attachment
    form = AttachmentForm
    readonly_fields = ('is_image', 'user', 'created_at')
    max_num = 3

class EnterpriseAdmin(MyCompareVersionAdmin):
    inlines = [AttachmentInline]
   # ...
}}}

It's unclear where and how we need to grab and pass `request.user` parameter to `AttachmentForm`. After some trial and error, I ended up with this workaround:

{{{#!python
class EnterpriseAdmin(MyCompareVersionAdmin):
    inlines = [AttachmentInline]

    def save_related(self, request, form, formsets, change):
        AttachmentForm.user = request.user
        super(MyCompareVersionAdmin, self).save_related(request, form, formsets, change)
}}}

Related modifications in `AttachmentForm`:

{{{#!python
user = None

def __init__(self, *args, **kwargs):
    user = kwargs.pop('user', None)
    if user:
        self.user = user
        super(AttachmentForm, self).__init__(*args, **kwargs)
}}}

So I turned `user` to class attribute and set it from kwargs only if it's passed and it's not `None`.

It works, but I don't like this approach and It looks like a hack for me.

I think the solution on how to properly do it should be added to the docs in the same section along with frontend solution."	Uncategorized	new	contrib.admin	1.10	Normal		admin, form, formset, parameter		Unreviewed	0	0	0	0	0	0