예제 #1
0
    def test_field_editability_depends_on_feature(self):
        """
        Test QgsVectorLayerUtils.fieldEditabilityDependsOnFeature
        """
        layer = createLayerWithOnePoint()

        # not joined fields, so answer should be False
        self.assertFalse(
            QgsVectorLayerUtils.fieldEditabilityDependsOnFeature(layer, 0))
        self.assertFalse(
            QgsVectorLayerUtils.fieldEditabilityDependsOnFeature(layer, 1))

        # joined field
        layer2 = QgsVectorLayer(
            "Point?field=fldtxt2:string&field=fldint:integer", "addfeat",
            "memory")
        join_info = QgsVectorLayerJoinInfo()
        join_info.setJoinLayer(layer2)
        join_info.setJoinFieldName('fldint')
        join_info.setTargetFieldName('fldint')
        join_info.setUsingMemoryCache(True)
        layer.addJoin(join_info)
        layer.updateFields()

        self.assertEqual([f.name() for f in layer.fields()],
                         ['fldtxt', 'fldint', 'addfeat_fldtxt2'])
        self.assertFalse(
            QgsVectorLayerUtils.fieldEditabilityDependsOnFeature(layer, 0))
        self.assertFalse(
            QgsVectorLayerUtils.fieldEditabilityDependsOnFeature(layer, 1))
        # join layer is not editable => regardless of the feature, the field will always be read-only
        self.assertFalse(
            QgsVectorLayerUtils.fieldEditabilityDependsOnFeature(layer, 2))

        # make join editable
        layer.removeJoin(layer2.id())
        join_info.setEditable(True)
        join_info.setUpsertOnEdit(True)
        layer.addJoin(join_info)
        layer.updateFields()
        self.assertEqual([f.name() for f in layer.fields()],
                         ['fldtxt', 'fldint', 'addfeat_fldtxt2'])

        # has upsert on edit => regardless of feature, we can create the join target to make the field editable
        self.assertFalse(
            QgsVectorLayerUtils.fieldEditabilityDependsOnFeature(layer, 2))

        layer.removeJoin(layer2.id())
        join_info.setEditable(True)
        join_info.setUpsertOnEdit(False)
        layer.addJoin(join_info)
        layer.updateFields()
        self.assertEqual([f.name() for f in layer.fields()],
                         ['fldtxt', 'fldint', 'addfeat_fldtxt2'])

        # No upsert on edit => depending on feature, we either can edit the field or not, depending on whether
        # the join target feature already exists or not
        self.assertTrue(
            QgsVectorLayerUtils.fieldEditabilityDependsOnFeature(layer, 2))
예제 #2
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 def buildJoin(self, originalLyr, originalLyrFieldName, joinnedLyr,
               joinLyrFieldName):
     """
     Builds a join bewteen lyr and joinnedLyr.
     :param originalLyr: QgsVectorLayer original layer;
     :param originalLyrFieldName: (str) name of the field;
     :param joinnedLyr: QgsVectorLayer lyr to be joinned to originalLayer;
     :param joinLyrFieldName: (str) name of the join field name (usually primary key of joinnedLyr)
     """
     joinObject = QgsVectorLayerJoinInfo()
     joinObject.setJoinFieldName(joinLyrFieldName)
     joinObject.setTargetFieldName(originalLyrFieldName)
     joinObject.setJoinLayer(joinnedLyr)
     joinObject.setJoinFieldNamesSubset()
     joinObject.upsertOnEdit(True)  #set to enable edit on original lyr
     joinObject.setCascadedDelete(True)
     joinObject.setDynamicFormEnabled(True)
     joinObject.setEditable(True)
     joinObject.setUsingMemoryCache(True)
     originalLyr.addJoin(joinObject)
예제 #3
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 def joinTables(self):
     d, f = self.lyrPair()
     for k, v in d.items():
         target = QgsProject.instance().mapLayer(k)
         layerToJoin = QgsProject.instance().mapLayer(v)
         fieldToJoin = QgsProject.instance()
         symb = QgsVectorLayerJoinInfo()
         symb.setJoinFieldName('id_feature')
         symb.setTargetFieldName('id')
         symb.setJoinLayerId(layerToJoin.id())
         symb.setUsingMemoryCache(True)
         symb.setEditable(True)
         symb.setDynamicFormEnabled(True)
         symb.setUpsertOnEdit(True)
         symb.setPrefix('')
         symb.setJoinFieldNamesSubset([
             'ocultar', 'legenda', 'tamanhotxt', 'justtxt', 'orient_txt',
             'orient_simb', 'offset_txt', 'offset_simb', 'prioridade',
             'offset_txt_x', 'offset_txt_y'
         ])
         symb.setJoinLayer(layerToJoin)
         target.addJoin(symb)
예제 #4
0
 def joinTables(self):
     d, f = self.lyrPair()
     for k, v in d.items():
         target = QgsProject.instance().mapLayer(k)
         layerToJoin = QgsProject.instance().mapLayer(v)
         """  # tests for previous joined layers - under research
         i = QgsProject.instance().mapLayers().values()
         for layer in i:
             fh_lyr = layer
             joinsInfo = fh_lyr.vectorJoins()
             
             if joinsInfo != 0:
                 QMessageBox.critical(iface.mainWindow(), "Error",
                                     "Previously Joins already exists! Please remove joins and try again.")
                 break  # ask for remove previous joins. use removeJoinTables()
             else:
         """
         # target.removeJoin(layerToJoin.id())
         fieldToJoin = QgsProject.instance()
         symb = QgsVectorLayerJoinInfo()
         symb.setJoinFieldName('id_feature')
         symb.setTargetFieldName('id')
         symb.setJoinLayerId(layerToJoin.id())
         symb.setUsingMemoryCache(True)
         symb.setEditable(True)
         symb.setDynamicFormEnabled(True)
         symb.setUpsertOnEdit(True)
         symb.setPrefix('')
         symb.setJoinFieldNamesSubset([
             'ocultar', 'legenda', 'tamanhotxt', 'justtxt', 'orient_txt',
             'orient_simb', 'offset_txt', 'offset_simb', 'prioridade',
             'offset_txt_x', 'offset_txt_y'
         ])
         symb.setJoinLayer(layerToJoin)
         target.addJoin(symb)
         layerToJoin.startEditing()
         target.triggerRepaint()
    def processAlgorithm(self, parameters, context, feedback):

        t_file = self.parameterAsVectorLayer(
            parameters,
            self.FILE_TABLE,
            context
        )
        t_troncon = self.parameterAsVectorLayer(
            parameters,
            self.SEGMENTS_TABLE,
            context
        )
        t_obs = self.parameterAsVectorLayer(
            parameters,
            self.OBSERVATIONS_TABLE,
            context
        )
        t_regard = self.parameterAsVectorLayer(
            parameters,
            self.MANHOLES_TABLE,
            context
        )

        g_regard = self.parameterAsVectorLayer(
            parameters,
            self.GEOM_MANHOLES,
            context
        )
        g_troncon = self.parameterAsVectorLayer(
            parameters,
            self.GEOM_SEGMENT,
            context
        )
        g_obs = self.parameterAsVectorLayer(
            parameters,
            self.GEOM_OBSERVATION,
            context
        )

        v_regard = self.parameterAsVectorLayer(
            parameters,
            self.VIEW_MANHOLES_GEOLOCALIZED,
            context
        )

        # define variables
        variables = context.project().customVariables()
        variables['itv_rerau_t_file'] = t_file.id()
        variables['itv_rerau_t_troncon'] = t_troncon.id()
        variables['itv_rerau_t_obs'] = t_obs.id()
        variables['itv_rerau_t_regard'] = t_regard.id()

        variables['itv_rerau_g_regard'] = g_regard.id()
        variables['itv_rerau_g_troncon'] = g_troncon.id()
        variables['itv_rerau_g_obs'] = g_obs.id()

        context.project().setCustomVariables(variables)

        # define relations
        relations = [
            {
                'id': 'fk_obs_id_file',
                'name': tr('Link File - Observation'),
                'referencingLayer': t_obs.id(),
                'referencingField': 'id_file',
                'referencedLayer': t_file.id(),
                'referencedField': 'id'
            }, {
                'id': 'fk_regard_id_file',
                'name': tr('Link File - Manhole'),
                'referencingLayer': t_regard.id(),
                'referencingField': 'id_file',
                'referencedLayer': t_file.id(),
                'referencedField': 'id'
            }, {
                'id': 'fk_troncon_id_file',
                'name': tr('Link File - Pipe segment'),
                'referencingLayer': t_troncon.id(),
                'referencingField': 'id_file',
                'referencedLayer': t_file.id(),
                'referencedField': 'id'
            }, {
                'id': 'fk_obs_id_troncon',
                'name': tr('Link Pipe segment - Observation'),
                'referencingLayer': t_obs.id(),
                'referencingField': 'id_troncon',
                'referencedLayer': t_troncon.id(),
                'referencedField': 'id'
            }, {
                'id': 'fk_regard_id_geom_regard',
                'name': tr('Link Manhole inspection - Reference'),
                'referencingLayer': t_regard.id(),
                'referencingField': 'id_geom_regard',
                'referencedLayer': g_regard.id(),
                'referencedField': 'id'
            }, {
                'id': 'fk_troncon_id_geom_trononc',
                'name': tr('Link Pipe segment inspection - Reference'),
                'referencingLayer': t_troncon.id(),
                'referencingField': 'id_geom_troncon',
                'referencedLayer': g_troncon.id(),
                'referencedField': 'id'
            }
        ]

        relation_manager = context.project().relationManager()
        for rel_def in relations:
            feedback.pushInfo(
                'Link: {}'.format(rel_def['name'])
            )
            rel = QgsRelation()
            rel.setId(rel_def['id'])
            rel.setName(rel_def['name'])
            rel.setReferencingLayer(rel_def['referencingLayer'])
            rel.setReferencedLayer(rel_def['referencedLayer'])
            rel.addFieldPair(
                rel_def['referencingField'],
                rel_def['referencedField']
            )
            rel.setStrength(QgsRelation.Association)
            relation_manager.addRelation(rel)
            feedback.pushInfo(
                'Count relations {}'.format(
                    len(relation_manager.relations())
                )
            )

        joins = [
            {
                'layer': t_obs,
                'targetField': 'id_troncon',
                'joinLayer': t_troncon,
                'joinField': 'id',
                'fieldNamesSubset': ['ack']
            }, {
                'layer': g_obs,
                'targetField': 'id',
                'joinLayer': t_obs,
                'joinField': 'id',
                'fieldNamesSubset': []
            }
        ]
        for j_def in joins:
            layer = j_def['layer']

            join = QgsVectorLayerJoinInfo()
            join.setJoinFieldName(j_def['joinField'])
            join.setJoinLayerId(j_def['joinLayer'].id())
            join.setTargetFieldName(j_def['targetField'])

            if j_def['fieldNamesSubset']:
                join.setJoinFieldNamesSubset(j_def['fieldNamesSubset'])

            join.setUsingMemoryCache(False)
            join.setPrefix('')
            join.setEditable(False)
            join.setCascadedDelete(False)

            join.setJoinLayer(j_def['joinLayer'])

            layer.addJoin(join)
            layer.updateFields()

        # load styles
        styles = [
            {
                'layer': t_file,
                'namedStyles': [
                    {
                        'file': 'itv_file_fields.qml',
                        'type': QgsMapLayer.Fields
                    }, {
                        'file': 'itv_file_actions.qml',
                        'type': QgsMapLayer.Actions
                    }
                ]
            }, {
                'layer': t_troncon,
                'namedStyles': [
                    {
                        'file': 'itv_troncon_fields.qml',
                        'type': QgsMapLayer.Fields
                    }, {
                        'file': 'itv_troncon_table.qml',
                        'type': QgsMapLayer.AttributeTable
                    }
                ]
            }, {
                'layer': t_obs,
                'namedStyles': [
                    {
                        'file': 'itv_obs_fields.qml',
                        'type': QgsMapLayer.Fields
                    }, {
                        'file': 'itv_obs_table.qml',
                        'type': QgsMapLayer.AttributeTable
                    }
                ]
            }, {
                'layer': t_regard,
                'namedStyles': [
                    {
                        'file': 'itv_regard_fields.qml',
                        'type': QgsMapLayer.Fields
                    }, {
                        'file': 'itv_regard_forms.qml',
                        'type': QgsMapLayer.Forms
                    }, {
                        'file': 'itv_regard_table.qml',
                        'type': QgsMapLayer.AttributeTable
                    }
                ]
            }, {
                'layer': g_regard,
                'namedStyles': [
                    {
                        'file': 'itv_geom_regard_fields.qml',
                        'type': QgsMapLayer.Fields
                    }, {
                        'file': 'itv_geom_regard_symbology.qml',
                        'type': QgsMapLayer.Symbology
                    }
                ]
            }, {
                'layer': g_troncon,
                'namedStyles': [
                    {
                        'file': 'itv_geom_troncon_fields.qml',
                        'type': QgsMapLayer.Fields
                    }, {
                        'file': 'itv_geom_troncon_symbology.qml',
                        'type': QgsMapLayer.Symbology
                    }, {
                        'file': 'itv_geom_troncon_actions.qml',
                        'type': QgsMapLayer.Actions
                    }
                ]
            }, {
                'layer': g_obs,
                'namedStyles': [
                    {
                        'file': 'itv_geom_obs_fields.qml',
                        'type': QgsMapLayer.Fields
                    }, {
                        'file': 'itv_geom_obs_symbology.qml',
                        'type': QgsMapLayer.Symbology
                    }
                ]
            }, {
                'layer': v_regard,
                'namedStyles': [
                    {
                        'file': 'itv_view_regard_fields.qml',
                        'type': QgsMapLayer.Fields
                    }, {
                        'file': 'itv_view_regard_symbology.qml',
                        'type': QgsMapLayer.Symbology
                    }, {
                        'file': 'itv_view_regard_labeling.qml',
                        'type': QgsMapLayer.Labeling
                    }
                ]
            }
        ]
        for style in styles:
            layer = style['layer']
            for n_style in style['namedStyles']:
                layer.loadNamedStyle(
                    resources_path('styles', n_style['file']),
                    categories=n_style['type']
                )
                # layer.saveStyleToDatabase('style', 'default style', True, '')
                layer.triggerRepaint()

        # Creation de la symbologie g_obs
        g_obs_rules = (
            'BAA', 'BAB', 'BAC', 'BAD', 'BAE', 'BAF', 'BAG', 'BAH',
            'BAI', 'BAJ', 'BAK', 'BAL', 'BAM', 'BAN', 'BAO', 'BAP',
            'BBA', 'BBB', 'BBC', 'BBD', 'BBE', 'BBF', 'BBG', 'BBH',
            'BCA', 'BCB', 'BCC', 'BDA', 'BDB', 'BDC', 'BDD', 'BDE',
            'BDF', 'BDG'
        )
        g_obs_rule_descs = {
            'BAA': 'Déformation',
            'BAB': 'Fissure',
            'BAC': 'Rupture/Effondrement',
            'BAD': 'Elt maçonnerie',
            'BAE': 'Mortier manquant',
            'BAF': 'Dégradation de surface',
            'BAG': 'Branchement pénétrant',
            'BAH': 'Raccordement défectueux',
            'BAI': 'Joint étanchéité apparent',
            'BAJ': 'Déplacement d\'assemblage',
            'BAK': 'Défaut de révêtement',
            'BAL': 'Réparation défectueuse',
            'BAM': 'Défaut soudure',
            'BAN': 'Conduite poreuse',
            'BAO': 'Sol visible',
            'BAP': 'Trou visible',
            'BBA': 'Racines',
            'BBB': 'Dépots Adhérents',
            'BBC': 'Dépôts',
            'BBD': 'Entrée de terre',
            'BBE': 'Autres obstacles',
            'BBF': 'Infiltration',
            'BBG': 'Exfiltration',
            'BBH': 'Vermine',
            'BCA': 'Raccordement',
            'BCB': 'Réparation',
            'BCC': 'Courbure de collecteur',
            'BDA': 'Photographie générale',
            'BDB': 'Remarque générale',
            'BDC': 'Inspection abandonnée',
            'BDD': 'Niveau d\'eau',
            'BDE': 'Ecoulement dans une canlisation entrante',
            'BDF': 'Atmosphère canalisation',
            'BDG': 'Perte de visibilité'
        }
        g_obs_rootrule = QgsRuleBasedRenderer.Rule(None)
        rendering_pass_idx = len(g_obs_rules)
        for rule in g_obs_rules:
            # get svg path
            svg_path = resources_path('styles', 'img_obs', rule + '.svg')
            # create svg symbol layer
            svg_symbol_layer = QgsSvgMarkerSymbolLayer(svg_path)
            svg_symbol_layer.setRenderingPass(rendering_pass_idx)
            # create white square symbol layer for the backend
            simple_symbol_layer = QgsSimpleMarkerSymbolLayer(
                shape=QgsSimpleMarkerSymbolLayerBase.Circle,
                size=svg_symbol_layer.size(),
                color=QColor('white'),
                strokeColor=QColor('white')
            )
            simple_symbol_layer.setRenderingPass(rendering_pass_idx)
            # create marker
            svg_marker = QgsMarkerSymbol()
            # set the backend symbol layer
            svg_marker.changeSymbolLayer(0, simple_symbol_layer)
            # add svg symbol layer
            svg_marker.appendSymbolLayer(svg_symbol_layer)
            # create rule
            svg_rule = QgsRuleBasedRenderer.Rule(
                svg_marker, 0, 10000,
                QgsExpression.createFieldEqualityExpression('a', rule),
                rule
            )
            if rule in g_obs_rule_descs:
                svg_rule.setLabel(g_obs_rule_descs[rule])
                svg_rule.setDescription('{}: {}'.format(
                    rule,
                    g_obs_rule_descs[rule]
                ))
            # add rule
            g_obs_rootrule.appendChild(svg_rule)
            rendering_pass_idx -= 1
        g_obs_rootrule.appendChild(
            QgsRuleBasedRenderer.Rule(
                QgsMarkerSymbol.createSimple(
                    {
                        'name': 'circle',
                        'color': '#0000b2',
                        'outline_color': '#0000b2',
                        'size': '1'
                    }
                ),
                0, 10000, 'ELSE', 'Autres'
            )
        )
        g_obs.setRenderer(QgsRuleBasedRenderer(g_obs_rootrule))
        feedback.pushInfo('Project has been setup')
        return {}
예제 #6
0
    def test_field_is_read_only(self):
        """
        Test fieldIsReadOnly
        """
        layer = createLayerWithOnePoint()
        # layer is not editable => all fields are read only
        self.assertTrue(QgsVectorLayerUtils.fieldIsReadOnly(layer, 0))
        self.assertTrue(QgsVectorLayerUtils.fieldIsReadOnly(layer, 1))

        layer.startEditing()
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 0))
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 1))

        field = QgsField('test', QVariant.String)
        layer.addAttribute(field)
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 0))
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 1))
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 2))

        # simulate read-only field from provider
        field = QgsField('test2', QVariant.String)
        field.setReadOnly(True)
        layer.addAttribute(field)
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 0))
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 1))
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 2))
        self.assertTrue(QgsVectorLayerUtils.fieldIsReadOnly(layer, 3))

        layer.rollBack()
        layer.startEditing()

        # edit form config specifies read only
        form_config = layer.editFormConfig()
        form_config.setReadOnly(1, True)
        layer.setEditFormConfig(form_config)
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 0))
        self.assertTrue(QgsVectorLayerUtils.fieldIsReadOnly(layer, 1))
        form_config.setReadOnly(1, False)
        layer.setEditFormConfig(form_config)
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 0))
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 1))

        # joined field
        layer2 = QgsVectorLayer(
            "Point?field=fldtxt2:string&field=fldint:integer", "addfeat",
            "memory")
        join_info = QgsVectorLayerJoinInfo()
        join_info.setJoinLayer(layer2)
        join_info.setJoinFieldName('fldint')
        join_info.setTargetFieldName('fldint')
        join_info.setUsingMemoryCache(True)
        layer.addJoin(join_info)
        layer.updateFields()

        self.assertEqual([f.name() for f in layer.fields()],
                         ['fldtxt', 'fldint', 'addfeat_fldtxt2'])
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 0))
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 1))
        # join layer is not editable
        self.assertTrue(QgsVectorLayerUtils.fieldIsReadOnly(layer, 2))

        # make join editable
        layer.removeJoin(layer2.id())
        join_info.setEditable(True)
        layer.addJoin(join_info)
        layer.updateFields()
        self.assertEqual([f.name() for f in layer.fields()],
                         ['fldtxt', 'fldint', 'addfeat_fldtxt2'])

        # should still be read only -- the join layer itself is not editable
        self.assertTrue(QgsVectorLayerUtils.fieldIsReadOnly(layer, 2))

        layer2.startEditing()
        self.assertFalse(QgsVectorLayerUtils.fieldIsReadOnly(layer, 2))

        # but now we set a property on the join layer which blocks editing for the feature...
        form_config = layer2.editFormConfig()
        form_config.setReadOnly(0, True)
        layer2.setEditFormConfig(form_config)
        # should now be read only -- the joined layer edit form config prohibits edits
        self.assertTrue(QgsVectorLayerUtils.fieldIsReadOnly(layer, 2))
예제 #7
0
    def testJoinedFieldIsEditableRole(self):
        layer = QgsVectorLayer("Point?field=id_a:integer", "addfeat", "memory")
        layer2 = QgsVectorLayer("Point?field=id_b:integer&field=value_b",
                                "addfeat", "memory")
        QgsProject.instance().addMapLayers([layer, layer2])

        # editable join
        join_info = QgsVectorLayerJoinInfo()
        join_info.setTargetFieldName("id_a")
        join_info.setJoinLayer(layer2)
        join_info.setJoinFieldName("id_b")
        join_info.setPrefix("B_")
        join_info.setEditable(True)
        join_info.setUpsertOnEdit(True)
        layer.addJoin(join_info)

        m = QgsFieldModel()
        m.setLayer(layer)

        self.assertIsNone(
            m.data(m.indexFromName('id_a'),
                   QgsFieldModel.JoinedFieldIsEditable))
        self.assertTrue(
            m.data(m.indexFromName('B_value_b'),
                   QgsFieldModel.JoinedFieldIsEditable))
        self.assertIsNone(
            m.data(m.indexFromName('an expression'),
                   QgsFieldModel.JoinedFieldIsEditable))
        self.assertIsNone(
            m.data(m.indexFromName(None), QgsFieldModel.JoinedFieldIsEditable))
        m.setAllowExpression(True)
        m.setExpression('an expression')
        self.assertIsNone(
            m.data(m.indexFromName('an expression'),
                   QgsFieldModel.JoinedFieldIsEditable))
        m.setAllowEmptyFieldName(True)
        self.assertIsNone(
            m.data(m.indexFromName(None), QgsFieldModel.JoinedFieldIsEditable))

        proxy_m = QgsFieldProxyModel()
        proxy_m.setFilters(QgsFieldProxyModel.AllTypes
                           | QgsFieldProxyModel.HideReadOnly)
        proxy_m.sourceFieldModel().setLayer(layer)
        self.assertEqual(proxy_m.rowCount(), 2)
        self.assertEqual(proxy_m.data(proxy_m.index(0, 0)), 'id_a')
        self.assertEqual(proxy_m.data(proxy_m.index(1, 0)), 'B_value_b')

        # not editable join
        layer3 = QgsVectorLayer("Point?field=id_a:integer", "addfeat",
                                "memory")
        QgsProject.instance().addMapLayers([layer3])
        join_info = QgsVectorLayerJoinInfo()
        join_info.setTargetFieldName("id_a")
        join_info.setJoinLayer(layer2)
        join_info.setJoinFieldName("id_b")
        join_info.setPrefix("B_")
        join_info.setEditable(False)

        layer3.addJoin(join_info)
        m = QgsFieldModel()
        m.setLayer(layer3)

        self.assertIsNone(
            m.data(m.indexFromName('id_a'),
                   QgsFieldModel.JoinedFieldIsEditable))
        self.assertFalse(
            m.data(m.indexFromName('B_value_b'),
                   QgsFieldModel.JoinedFieldIsEditable))
        self.assertIsNone(
            m.data(m.indexFromName('an expression'),
                   QgsFieldModel.JoinedFieldIsEditable))
        self.assertIsNone(
            m.data(m.indexFromName(None), QgsFieldModel.JoinedFieldIsEditable))
        m.setAllowExpression(True)
        m.setExpression('an expression')
        self.assertIsNone(
            m.data(m.indexFromName('an expression'),
                   QgsFieldModel.JoinedFieldIsEditable))
        m.setAllowEmptyFieldName(True)
        self.assertIsNone(
            m.data(m.indexFromName(None), QgsFieldModel.JoinedFieldIsEditable))

        proxy_m = QgsFieldProxyModel()
        proxy_m.sourceFieldModel().setLayer(layer3)
        proxy_m.setFilters(QgsFieldProxyModel.AllTypes
                           | QgsFieldProxyModel.HideReadOnly)
        self.assertEqual(proxy_m.rowCount(), 1)
        self.assertEqual(proxy_m.data(proxy_m.index(0, 0)), 'id_a')