django - Whole model as read-only

Question

Is there a way to make a model read-only in the django admin? but I mean the whole model. So, no adding, no deleting, no changing, just see the objects and the fields, everything as read-only?

Answer 1

ModelAdmin provides the hook get_readonly_fields() - the following is untested, my idea being to determine all fields the way ModelAdmin does it, without running into a recursion with the readonly fields themselves:

from django.contrib.admin.util import flatten_fieldsets

class ReadOnlyAdmin(ModelAdmin):
    def get_readonly_fields(self, request, obj=None):
        if self.declared_fieldsets:
            fields = flatten_fieldsets(self.declared_fieldsets)
        else:
            form = self.get_formset(request, obj).form
            fields = form.base_fields.keys()
        return fields

then subclass/mixin this admin whereever it should be a read-only admin.

For add/delete, and to make their buttons disappear, you'll probably also want to add

    def has_add_permission(self, request):
        # Nobody is allowed to add
        return False
    def has_delete_permission(self, request, obj=None):
        # Nobody is allowed to delete
        return False

P.S.: In ModelAdmin, if has_change_permission (lookup or your override) returns False, you don't get to the change view of an object - and the link to it won't even be shown. It would actually be cool if it did, and the default get_readonly_fields() checked the change permission and set all fields to readonly in that case, like above. That way non-changers could at least browse the data... given that the current admin structure assumes view=edit, as jathanism points out, this would probably require the introduction of a "view" permission on top of add/change/delete...

EDIT: regarding setting all fields readonly, also untested but looking promising:

readonly_fields = MyModel._meta.get_all_field_names()

EDIT: Here's another one

if self.declared_fieldsets:
    return flatten_fieldsets(self.declared_fieldsets)
else:
    return list(set(
        [field.name for field in self.opts.local_fields] +
        [field.name for field in self.opts.local_many_to_many]
    ))