Deprecate GeoModelAdmin and OSMGeoAdmin

[Claude Paroz]

The geometry fields now have default map widgets, so the need of gis-specific ModelAdmin classes is therefore less relevant.

However, the fact that ModelAdmin.formfield_for_dbfield is not documented does not help, so I'd suggest to document it first.

[Tim Graham]

Could you describe the relevance of formfield_for_dbfield in a bit more detail?

[Claude Paroz]

Sure. The typical example is to be sure all geometry widgets use a specific map widget, or specific map widget attributes.
With formfield_overrides, you'd have to specify all field types:

class MyModelAdmin(admin.ModelAdmin):
    formfield_overrides = {
        models.PointField: {'widget': MyCustomMapWidget},
        models.PolygonField: {'widget': MyCustomMapWidget},
        models.LineField: {'widget': MyCustomMapWidget},
        models.MultiPointField: {'widget': MyCustomMapWidget},
        ...
    }

which is not nice if you have many geometry field types in your project. I think it's a case where formfield_for_dbfield is handy:

class MyModelAdmin(admin.ModelAdmin):
    def formfield_for_dbfield(self, db_field, request, **kwargs):
        if isinstance(db_field, models.GeometryField) and db_field.dim < 3:
            kwargs['widget'] = OSMWidget(default_lon=151, default_lat=-33)
            return db_field.formfield(**kwargs)
        else:
            return super(GeoModelAdmin, self).formfield_for_dbfield(db_field, request, **kwargs)

An alternative would be to still provide a GIS admin utility (subclass or mixin) which sets the same map widget for all geometry fields, like the current GeoModelAdmin.get_map_widget(). Basically the current code without all the boiler plate code copying class attributes to widget attributes.

[Tim Graham]

Another idea: I like to see this sort of issue solved at the form level, if possible, to allow reusing the solution outside the admin.

[Giannis Adamopoulos]

​Submitted PR

[Mariusz Felisiak <felisiak.mariusz@…>]

In 4555aa0a:

Fixed #27674 -- Deprecated GeoModelAdmin and OSMGeoAdmin.

Co-authored-by: Mariusz Felisiak <felisiak.mariusz@…>

[Nick Pope]

While looking into #33372 I noticed that there are two OpenLayersWidget classes:

• django.contrib.gis.admin.widgets.OpenLayersWidget - this is used by the deprecated GeoModelAdmin class and targets OpenLayers 2.x
• django.contrib.gis.forms.widgets.OpenLayersWidget - this is used as a parent to OSMWidget (used by the new GISModelAdmin) and targets OpenLayers 3.x

Deprecation warnings were added for GeoModelAdmin and OSMGeoAdmin as part of this ticket but .admin.widgets.OpenLayersWidget has no warning. Do we need to add one?

Do we also need to warn about gis/admin/openlayers.html and gis/admin/osm.html templates going away? (Not sure whether we add a documentation note?)

[Mariusz Felisiak]

Replying to Nick Pope:

While looking into #33372 I noticed that there are two OpenLayersWidget classes:

• django.contrib.gis.admin.widgets.OpenLayersWidget - this is used by the deprecated GeoModelAdmin class and targets OpenLayers 2.x
• django.contrib.gis.forms.widgets.OpenLayersWidget - this is used as a parent to OSMWidget (used by the new GISModelAdmin) and targets OpenLayers 3.x

Deprecation warnings were added for GeoModelAdmin and OSMGeoAdmin as part of this ticket but .admin.widgets.OpenLayersWidget has no warning. Do we need to add one?

Agreed, we can deprecate django.contrib.gis.admin.widgets.OpenLayersWidget in Django 4.1 and remove it in 5.0. Let's reopen.

Do we also need to warn about gis/admin/openlayers.html and gis/admin/osm.html templates going away? (Not sure whether we add a documentation note?)

As far as I'm concerned, it is not needed.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 44814509:

Refs #27674 -- Added tests for GISModelAdmin.gis_widget_kwargs.

[Mariusz Felisiak]

​PR

[GitHub <noreply@…>]

In eeb0bb6:

Refs #27674 --- Deprecated django.contrib.gis.admin.OpenLayersWidget.

[Mariusz Felisiak <felisiak.mariusz@…>]

In 4982958:

Refs #27674 -- Removed GeoModelAdmin and OSMGeoAdmin per deprecation timeline.

[Mariusz Felisiak <felisiak.mariusz@…>]

In ce7b4f3:

Refs #27674 -- Removed django.contrib.gis.admin.OpenLayersWidget per deprecation timeline.