Method lookup_allowed

django/contrib/admin/options.py:496–558

(self, lookup, value, request)

        )

    def lookup_allowed(self, lookup, value, request):
        from django.contrib.admin.filters import SimpleListFilter

        model = self.model
        # Check FKey lookups that are allowed, so that popups produced by
        # ForeignKeyRawIdWidget, on the basis of ForeignKey.limit_choices_to,
        # are allowed to work.
        for fk_lookup in model._meta.related_fkey_lookups:
            # As ``limit_choices_to`` can be a callable, invoke it here.
            if callable(fk_lookup):
                fk_lookup = fk_lookup()
            if (lookup, value) in widgets.url_params_from_lookup_dict(
                fk_lookup
            ).items():
                return True

        relation_parts = []
        prev_field = None
        parts = lookup.split(LOOKUP_SEP)
        for part in parts:
            try:
                field = model._meta.get_field(part)
            except FieldDoesNotExist:
                # Lookups on nonexistent fields are ok, since they're ignored
                # later.
                break
            if not prev_field or (
                prev_field.is_relation
                and field not in model._meta.parents.values()
                and field is not model._meta.auto_field
                and (
                    model._meta.auto_field is None
                    or part not in getattr(prev_field, "to_fields", [])
                )
                and (field.is_relation or not field.primary_key)
            ):
                relation_parts.append(part)
            if not getattr(field, "path_infos", None):
                # This is not a relational field, so further parts
                # must be transforms.
                break
            prev_field = field
            model = field.path_infos[-1].to_opts.model

        if len(relation_parts) <= 1:
            # Either a local field filter, or no fields at all.
            return True
        valid_lookups = {self.date_hierarchy}
        for filter_item in self.get_list_filter(request):
            if isinstance(filter_item, type) and issubclass(
                filter_item, SimpleListFilter
            ):
                valid_lookups.add(filter_item.parameter_name)
            elif isinstance(filter_item, (list, tuple)):
                valid_lookups.add(filter_item[0])
            else:
                valid_lookups.add(filter_item)