✨ Add backend filter for "Value Relation" widget type (key-value fields)

g3w-admin/core/api/filters.py

@@ -22,6 +22,7 @@
 )
 from rest_framework.exceptions import ParseError
 from urllib.parse import unquote
+from core.utils.qgisapi import get_qgis_layer, get_qgis_features
 from qdjango.models import Layer
 
 class BaseFilterBackend():
@@ -246,7 +247,8 @@ class FieldFilterBackend(BaseFilterBackend):
         'gte': '>=',
         'lte': '<=',
         'like': 'LIKE',
-        'ilike': 'ILIKE'
+        'ilike': 'ILIKE',
+        'in': 'IN'
     }
 
     def apply_filter(self, request, metadata_layer, qgis_feature_request, view):
@@ -296,11 +298,51 @@ def apply_filter(self, request, metadata_layer, qgis_feature_request, view):
 
                     pre_post_operator = '%' if field_operator in (
                         'like', 'ilike') else ''
+
+                    if "formatter" in request.query_params:
+                        formatter = request.query_params.get("formatter")
+                        if (
+                            formatter.isnumeric()
+                            and int(formatter) == 1
+                            and view.layer.has_value_relation_widget(field_name)
+                        ):
+                            config = qgis_layer.editorWidgetSetup(
+                                qgis_layer.fields().indexFromName(field_name)
+                            ).config()
+                            relation_qgs_layer = get_qgis_layer(
+                                view.layer.project.layer_set.get(qgs_layer_id=config["Layer"])
+                            )
+
+                            qfr = QgsFeatureRequest()
+                            pre_post_operator = "%" if field_operator in ("like", "ilike") else ""
+                            vr_single_search_expression = (
+                                "{field_name} {field_operator} {field_value}".format(
+                                    field_name=self._quote_identifier(config["Value"]),
+                                    field_operator=self.COMPARATORS_MAP[field_operator],
+                                    field_value=self._quote_value(
+                                        f"{pre_post_operator}{unquote(field_value)}{pre_post_operator}"
+                                    ),
+                                )
+                            )
+                            qfr.combineFilterExpression(vr_single_search_expression)
+                            features = get_qgis_features(relation_qgs_layer, qfr)
+
+                            if len(features) > 0:
+                                field_operator = "in"
+                                in_content = ",".join(["'" + str(f[config["Key"]]) + "'" for f in features])
+                                field_value = f"({in_content})"
+
+                    pre_post_operator = "%" if field_operator in ("like", "ilike") else ""
+                    if field_operator != 'in':
+                        quoted_field_value = self._quote_value(
+                            f'{pre_post_operator}{unquote(field_value)}{pre_post_operator}')
+                    else:
+                        quoted_field_value = field_value
+
                     single_search_expression = '{field_name} {field_operator} {field_value}'.format(
                         field_name=self._quote_identifier(field_name),
                         field_operator=self.COMPARATORS_MAP[field_operator],
-                        field_value=self._quote_value(
-                            f'{pre_post_operator}{unquote(field_value)}{pre_post_operator}')
+                        field_value=quoted_field_value
                     )
 
                     search_expression = f'{search_expression} {single_search_expression}'

g3w-admin/qdjango/models/projects.py

@@ -862,6 +862,14 @@ def add_style(self, style, qml):
 
         return result
 
+    def has_value_relation_widget(self, field_name: str) -> bool:
+        """
+        Check if a field_name has a QGIS Form ValueRelation Widget
+        """
+
+        edittypes = eval(self.edittypes)
+        return edittypes[field_name]["widgetv2type"] == "ValueRelation"
+
     @property
     def extent_rect(self):
         """Return dict of coordinates extension string

g3w-admin/qdjango/tests/base.py

@@ -38,6 +38,7 @@
 QGS328_FILE = 'gruppo-1_un-progetto_qgis328.qgs'
 QGS322_INITEXTENT_GEOCONSTRAINT_FILE = 'test_initextent_by_geoconstraint.qgs'
 QGS322_FORMATTING_DATE = 'Testing_Date_and_Datetime_formatting_322.qgs'
+QGS328_VALUE_RELATION = 'value_relation_qgis328.qgs'
 
 
 @override_settings(