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
35696	ModelAdmin is overruling the fields of ModelForm	Jurrian Tromp		"It seems that in ModelForm both `field_order` and `Meta.fields` ordering is being overruled by the admin change view. When rendering, the `form` object initially has the correct order, but when `admin_form` (django.contrib.admin.options:1826) is created, the `fieldsets` (django.contrib.admin.options:1781) coming from `get_fieldsets()` overrides the correct order in `form.fields`.

Something similar in #19514 has been reported before, more or less saying that ModelAdmin order should be leading. The problem with this however is that the reason you have a ModelForm here this way is because you try to do something more specialized. Consider this:

{{{
class Message(models.Model):
    some_readonly = models.CharField(...)
    overruled_model_m2m_field = models.ManyToManyField(through=SomeModel, ...)

class MessageForm(forms.ModelForm):
    some_form_field = forms.CharField()
    overruled_model_m2m_field = forms.CharField()

    field_order = ['some_form_field', 'overruled_model_m2m_field']

    class Meta:
        model = Message
        fields = ['some_form_field', 'overruled_model_m2m_field']
        exclude = ['some_readonly']

class MessageAdmin(admin.ModelAdmin):
    readonly_fields = ['some_readonly']
    form = MessageForm
}}}

**Resulting in the following unexpected behavior:**
1. For the fields MessageForm is ignored for the most part, MessageAdmin.get_fields() is de-facto shown.
 a. ModelAdmin `readonly_fields` are shown, even when they are excluded in the ModelForm.
 b. `MessageForm.field_order` has no effect when used in an admin view.
2. When a model field has `through`, it is not shown, as it should be an inline. Although it will be added to the fields again in the form (`MessageForm.overruled_model_m2m_field`)
 a. This makes it appear ""randomly"" in the ordering as it is updated to the end of base_fields (django.forms.models:324)

**Expected behavior:**
1. `MessageForm` takes precedence over `MessageAdmin`. 
  a. Excluded fields are not shown
  b. `ModelForm.Meta.fields` and `ModelForm.field_order` are used in favor of `ModelAdmin.get_fields()`
2. a. Fields with a through that are also specified in the form itself are ordered correctly according to 1b.

There are workarounds to get both the field order and readonly fields right, which comes down to defining `MessageAdmin.get_fields()` and/or `MessageAdmin.get_readonly_fields()`, to take full control. However, IMHO this should not be the default.
"	Bug	closed	Forms	4.2	Normal	invalid			Unreviewed	0	0	0	0	0	0