admin.py

from django.contrib import admin


class ContentManageableAdmin:
    """
    Base ModelAdmin class for any model that uses ContentManageable.
    """

    def save_model(self, request, obj, form, change):
        """
        Automatically set obj.creator = request.user when the model's created.
        """
        if not change:
            obj.creator = request.user
        else:
            obj.last_modified_by = request.user

        return super().save_model(request, obj, form, change)

    #
    # Automatically insert created/updated/creator into various places in the
    # admin options -- readonly fields, list_filter, etc. This is a bit extra-
    # clever to make it easier for subclasses to just say `readonly_fields =
    # ['foo']` and not worry about the superclass stuff.
    #

    def get_readonly_fields(self, request, obj=None):
        fields = list(super().get_readonly_fields(request, obj))
        return fields + ['created', 'updated', 'creator', 'last_modified_by']

    def get_list_filter(self, request):
        fields = list(super().get_list_filter(request))
        return fields + ['created', 'updated']

    def get_list_display(self, request):
        fields = list(super().get_list_display(request))
        return fields + ['created', 'updated']

    def get_fieldsets(self, request, obj=None):
        """
        Move the created/updated/creator fields to a fieldset of its own,
        at the end, and collapsed.
        """
        # Remove created/updated/creator from any existing fieldsets. They'll
        # be there if the child class didn't manually declare fieldsets.
        fieldsets = super().get_fieldsets(request, obj)
        for name, fieldset in fieldsets:
            for f in ('created', 'updated', 'creator', 'last_modified_by'):
                if f in fieldset['fields']:
                    fieldset['fields'].remove(f)

        # Now add these fields to a collapsed fieldset at the end.
        # FIXME: better name than "CMS metadata", that sucks.
        return fieldsets + [("CMS metadata", {
            'fields': [('creator', 'created'), ('last_modified_by', 'updated')],
            'classes': ('collapse',),
        })]


class ContentManageableModelAdmin(ContentManageableAdmin, admin.ModelAdmin):
    pass


class ContentManageableStackedInline(ContentManageableAdmin, admin.StackedInline):
    pass


class ContentManageableTabularInline(ContentManageableAdmin, admin.TabularInline):
    pass


class NameSlugAdmin(admin.ModelAdmin):
    prepopulated_fields = {"slug": ("name",)}