pass user instance to ModelForm

Using Django The Admin
1

I want to pass the user which is logged in to my form and save it automatically.
In addition I want the admin page to show an icon, I saved as base64 string on the admin page. I tried this, but it did not help me in the end.

models.py:

class Comment(Model):
    desc          = TextField(max_length=512)
    created       = DateTimeField(auto_now_add=True)
    updated       = DateTimeField(auto_now=True)
    user          = ForeignKey(User, on_delete=CASCADE)

    class Meta:
        abstract = True


class Screen(Comment):
    name             = CharField(unique=False, max_length=64)
    screen_type      = IntegerField()
    icon             = TextField(blank=True)

admin.py:

class ScreenAdminForm(forms.ModelForm):
    image_file = forms.ImageField(required = False, label = "Icon")
    
    class Meta:
        model           = Screen
        fields          = ["name", "screen_type", "image_file", "desc",]
        readonly_fields = ["user",]

    def __init__(self, *args, **kwargs):
        self.request = kwargs.pop('request')   # <--- KeyError
        super().__init__(*args, **kwargs)

    def clean_image_file(self):
        cleaned_data = super().clean()
        
        if "image_file" in self.changed_data:
            ...
        return cleaned_data

    def clean(self):
        """
        general clean method has to be used, because "icon" is not invoked in "fields" so, "clean_icon" would not be called otherwise.
        """
        cleaned_data = super().clean()
        if "image_file" in self.changed_data:
            self.instance.icon = self.cleaned_data["image"]
        return cleaned_data

@admin.register(Screen)
class ScreenAdmin(admin.ModelAdmin):
    form = ScreenAdminForm

    def get_form_kwargs(self):
        print("this method was called")  # <-- never called
        kwargs = super().get_form_kwargs()
        kwargs["request"] = self.request
        return kwargs

    def change_view(self, request, object_id, form_url = "", extra_context = None):
        """
        Adding the icon preview in the admin panel
        """
        
        print("change_view is called")
        extra_context = extra_context or {}
        try:
            img  = Screen.objects.get(pk = object_id).icon
            extra_context['icon'] = format_html(f"""<img src="{img}">""")
        except:
            pass
        return super().change_view(request, object_id, form_url, extra_context = extra_context)

First I tried to use get_form inside of ScreenAdmin but that resulted in the form being called twice, second time giving me a TypeError. Then I tried it with the get_form_kwargs() method and now I am out of ideas. What did I miss?

Goal: I want to save the user who edited the ScreenAdminForm automatically and make it non-editable even for the admin.
The “show icon” part is just mentioned because it makes use of the change_view() method, it is already implemented and working.

2

The ModelAdmin class is not a standard CBV - it doesn’t have the methods available to it that you would find with one of the Django-provided generic CBVs.

See the docs starting at ModelAdmin Options for all the details.

In this particular case, if you want to modify the model being saved by a form, see the save_model method. In fact, the example they provide in the docs at that point demonstrate exactly what you’re looking for.

3

Thanks for the super quick reply! I know I could use the save_model() method, but I was somehow convinced that there must be a way to do this the way I intended. Thanks for your time sir!