class TestQgsRelationEditWidget(unittest.TestCase):

    @classmethod
    def setUpClass(cls):
        """
        Setup the involved layers and relations for a n:m relation
        :return:
        """
        cls.mapCanvas = QgsMapCanvas()
        QgsGui.editorWidgetRegistry().initEditors(cls.mapCanvas)
        cls.dbconn = 'service=\'qgis_test\''
        if 'QGIS_PGTEST_DB' in os.environ:
            cls.dbconn = os.environ['QGIS_PGTEST_DB']
        # Create test layer
        cls.vl_b = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."books" sql=', 'books', 'postgres')
        cls.vl_a = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."authors" sql=', 'authors', 'postgres')
        cls.vl_link = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."books_authors" sql=', 'books_authors', 'postgres')

        QgsProject.instance().addMapLayer(cls.vl_b)
        QgsProject.instance().addMapLayer(cls.vl_a)
        QgsProject.instance().addMapLayer(cls.vl_link)

        cls.relMgr = QgsProject.instance().relationManager()

        cls.rel_a = QgsRelation()
        cls.rel_a.setReferencingLayer(cls.vl_link.id())
        cls.rel_a.setReferencedLayer(cls.vl_a.id())
        cls.rel_a.addFieldPair('fk_author', 'pk')
        cls.rel_a.setId('rel_a')
        assert(cls.rel_a.isValid())
        cls.relMgr.addRelation(cls.rel_a)

        cls.rel_b = QgsRelation()
        cls.rel_b.setReferencingLayer(cls.vl_link.id())
        cls.rel_b.setReferencedLayer(cls.vl_b.id())
        cls.rel_b.addFieldPair('fk_book', 'pk')
        cls.rel_b.setId('rel_b')
        assert(cls.rel_b.isValid())
        cls.relMgr.addRelation(cls.rel_b)

        # Our mock QgsVectorLayerTools, that allow injecting data where user input is expected
        cls.vltools = VlTools()

        assert(cls.vl_a.isValid())
        assert(cls.vl_b.isValid())
        assert(cls.vl_link.isValid())

    def setUp(self):
        self.startTransaction()

    def tearDown(self):
        self.rollbackTransaction()
        del self.transaction

    def test_delete_feature(self):
        """
        Check if a feature can be deleted properly
        """
        self.createWrapper(self.vl_a, '"name"=\'Erich Gamma\'')

        self.assertEqual(self.table_view.model().rowCount(), 1)

        self.assertEqual(1, len([f for f in self.vl_b.getFeatures()]))

        fid = next(self.vl_b.getFeatures(QgsFeatureRequest().setFilterExpression('"name"=\'Design Patterns. Elements of Reusable Object-Oriented Software\''))).id()

        self.widget.featureSelectionManager().select([fid])

        btn = self.widget.findChild(QToolButton, 'mDeleteFeatureButton')

        def clickOk():
            # Click the "Delete features" button on the confirmation message
            # box
            widget = self.widget.findChild(QMessageBox)
            buttonBox = widget.findChild(QDialogButtonBox)
            deleteButton = next((b for b in buttonBox.buttons() if buttonBox.buttonRole(b) == QDialogButtonBox.AcceptRole))
            deleteButton.click()

        QTimer.singleShot(1, clickOk)
        btn.click()

        # This is the important check that the feature is deleted
        self.assertEqual(0, len([f for f in self.vl_b.getFeatures()]))

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEqual(0, len([f for f in self.vl_link.getFeatures()]))

        self.assertEqual(self.table_view.model().rowCount(), 0)

    def test_list(self):
        """
        Simple check if several related items are shown
        """
        wrapper = self.createWrapper(self.vl_b)  # NOQA

        self.assertEqual(self.table_view.model().rowCount(), 4)

    @unittest.expectedFailure(os.environ.get('QT_VERSION', '5') == '4' and os.environ.get('TRAVIS_OS_NAME', '') == 'linux')  # It's probably not related to this variables at all, but that's the closest we can get to the real source of this problem at the moment...
    def test_add_feature(self):
        """
        Check if a new related feature is added
        """
        self.createWrapper(self.vl_a, '"name"=\'Douglas Adams\'')

        self.assertEqual(self.table_view.model().rowCount(), 0)

        self.vltools.setValues([None, 'The Hitchhiker\'s Guide to the Galaxy'])
        btn = self.widget.findChild(QToolButton, 'mAddFeatureButton')
        btn.click()

        # Book entry has been created
        self.assertEqual(2, len([f for f in self.vl_b.getFeatures()]))

        # Link entry has been created
        self.assertEqual(5, len([f for f in self.vl_link.getFeatures()]))

        self.assertEqual(self.table_view.model().rowCount(), 1)

    def test_link_feature(self):
        """
        Check if an existing feature can be linked
        """
        wrapper = self.createWrapper(self.vl_a, '"name"=\'Douglas Adams\'')  # NOQA

        f = QgsFeature(self.vl_b.fields())
        f.setAttributes([self.vl_b.dataProvider().defaultValueClause(0), 'The Hitchhiker\'s Guide to the Galaxy'])
        self.vl_b.addFeature(f)

        def choose_linked_feature():
            dlg = QApplication.activeModalWidget()
            dlg.setSelectedFeatures([f.id()])
            dlg.accept()

        btn = self.widget.findChild(QToolButton, 'mLinkFeatureButton')

        timer = QTimer()
        timer.setSingleShot(True)
        timer.setInterval(0)  # will run in the event loop as soon as it's processed when the dialog is opened
        timer.timeout.connect(choose_linked_feature)
        timer.start()

        btn.click()
        # magically the above code selects the feature here...

        link_feature = next(self.vl_link.getFeatures(QgsFeatureRequest().setFilterExpression('"fk_book"={}'.format(f[0]))))
        self.assertIsNotNone(link_feature[0])

        self.assertEqual(self.table_view.model().rowCount(), 1)

    def test_unlink_feature(self):
        """
        Check if a linked feature can be unlinked
        """
        wrapper = self.createWrapper(self.vl_b)   # NOQA

        # All authors are listed
        self.assertEqual(self.table_view.model().rowCount(), 4)

        it = self.vl_a.getFeatures(
            QgsFeatureRequest().setFilterExpression('"name" IN (\'Richard Helm\', \'Ralph Johnson\')'))

        self.widget.featureSelectionManager().select([f.id() for f in it])

        self.assertEqual(2, self.widget.featureSelectionManager().selectedFeatureCount())

        btn = self.widget.findChild(QToolButton, 'mUnlinkFeatureButton')
        btn.click()

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEqual(2, len([f for f in self.vl_link.getFeatures()]))

        self.assertEqual(2, self.table_view.model().rowCount())

    def test_discover_relations(self):
        """
        Test the automatic discovery of relations
        """
        relations = self.relMgr.discoverRelations([], [self.vl_a, self.vl_b, self.vl_link])
        relations = {r.name(): r for r in relations}
        self.assertEqual({'books_authors_fk_book_fkey', 'books_authors_fk_author_fkey'}, set(relations.keys()))

        ba2b = relations['books_authors_fk_book_fkey']
        self.assertTrue(ba2b.isValid())
        self.assertEqual('books_authors', ba2b.referencingLayer().name())
        self.assertEqual('books', ba2b.referencedLayer().name())
        self.assertEqual([0], ba2b.referencingFields())
        self.assertEqual([0], ba2b.referencedFields())

        ba2a = relations['books_authors_fk_author_fkey']
        self.assertTrue(ba2a.isValid())
        self.assertEqual('books_authors', ba2a.referencingLayer().name())
        self.assertEqual('authors', ba2a.referencedLayer().name())
        self.assertEqual([1], ba2a.referencingFields())
        self.assertEqual([0], ba2a.referencedFields())

        self.assertEqual([], self.relMgr.discoverRelations([self.rel_a, self.rel_b], [self.vl_a, self.vl_b, self.vl_link]))
        self.assertEqual(1, len(self.relMgr.discoverRelations([], [self.vl_a, self.vl_link])))

    def startTransaction(self):
        """
        Start a new transaction and set all layers into transaction mode.

        :return: None
        """
        lyrs = [self.vl_a, self.vl_b, self.vl_link]

        self.transaction = QgsTransaction.create(lyrs)
        self.transaction.begin()
        for l in lyrs:
            l.startEditing()

    def rollbackTransaction(self):
        """
        Rollback all changes done in this transaction.
        We always rollback and never commit to have the database in a pristine
        state at the end of each test.

        :return: None
        """
        lyrs = [self.vl_a, self.vl_b, self.vl_link]
        for l in lyrs:
            l.commitChanges()
        self.transaction.rollback()

    def createWrapper(self, layer, filter=None):
        """
        Basic setup of a relation widget wrapper.
        Will create a new wrapper and set its feature to the one and only book
        in the table.
        It will also assign some instance variables to help

         * self.widget The created widget
         * self.table_view The table view of the widget

        :return: The created wrapper
        """
        if layer == self.vl_b:
            relation = self.rel_b
            nmrel = self.rel_a
        else:
            relation = self.rel_a
            nmrel = self.rel_b

        self.wrapper = QgsRelationWidgetWrapper(layer, relation)
        self.wrapper.setConfig({'nm-rel': nmrel.id()})
        context = QgsAttributeEditorContext()
        context.setVectorLayerTools(self.vltools)
        self.wrapper.setContext(context)

        self.widget = self.wrapper.widget()
        self.widget.show()

        request = QgsFeatureRequest()
        if filter:
            request.setFilterExpression(filter)
        book = next(layer.getFeatures(request))
        self.wrapper.setFeature(book)

        self.table_view = self.widget.findChild(QTableView)
        return self.wrapper
Exemplo n.º 2
0
class TestQgsRelationEditWidget(unittest.TestCase):

    @classmethod
    def setUpClass(cls):
        """
        Setup the involved layers and relations for a n:m relation
        :return:
        """
        cls.mapCanvas = QgsMapCanvas()
        QgsGui.editorWidgetRegistry().initEditors(cls.mapCanvas)
        cls.dbconn = 'service=\'qgis_test\''
        if 'QGIS_PGTEST_DB' in os.environ:
            cls.dbconn = os.environ['QGIS_PGTEST_DB']
        # Create test layer
        cls.vl_b = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."books" sql=', 'books', 'postgres')
        cls.vl_a = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."authors" sql=', 'authors', 'postgres')
        cls.vl_link = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."books_authors" sql=', 'books_authors', 'postgres')

        QgsProject.instance().addMapLayer(cls.vl_b)
        QgsProject.instance().addMapLayer(cls.vl_a)
        QgsProject.instance().addMapLayer(cls.vl_link)

        cls.relMgr = QgsProject.instance().relationManager()

        cls.rel_a = QgsRelation()
        cls.rel_a.setReferencingLayer(cls.vl_link.id())
        cls.rel_a.setReferencedLayer(cls.vl_a.id())
        cls.rel_a.addFieldPair('fk_author', 'pk')
        cls.rel_a.setId('rel_a')
        assert(cls.rel_a.isValid())
        cls.relMgr.addRelation(cls.rel_a)

        cls.rel_b = QgsRelation()
        cls.rel_b.setReferencingLayer(cls.vl_link.id())
        cls.rel_b.setReferencedLayer(cls.vl_b.id())
        cls.rel_b.addFieldPair('fk_book', 'pk')
        cls.rel_b.setId('rel_b')
        assert(cls.rel_b.isValid())
        cls.relMgr.addRelation(cls.rel_b)

        # Our mock QgsVectorLayerTools, that allow injecting data where user input is expected
        cls.vltools = VlTools()

        assert(cls.vl_a.isValid())
        assert(cls.vl_b.isValid())
        assert(cls.vl_link.isValid())

    def setUp(self):
        self.startTransaction()

    def tearDown(self):
        self.rollbackTransaction()
        del self.transaction

    def test_delete_feature(self):
        """
        Check if a feature can be deleted properly
        """
        self.createWrapper(self.vl_a, '"name"=\'Erich Gamma\'')

        self.assertEqual(self.table_view.model().rowCount(), 1)

        self.assertEqual(1, len([f for f in self.vl_b.getFeatures()]))

        fid = next(self.vl_b.getFeatures(QgsFeatureRequest().setFilterExpression('"name"=\'Design Patterns. Elements of Reusable Object-Oriented Software\''))).id()

        self.widget.featureSelectionManager().select([fid])

        btn = self.widget.findChild(QToolButton, 'mDeleteFeatureButton')

        def clickOk():
            # Click the "Delete features" button on the confirmation message
            # box
            widget = self.widget.findChild(QMessageBox)
            buttonBox = widget.findChild(QDialogButtonBox)
            deleteButton = next((b for b in buttonBox.buttons() if buttonBox.buttonRole(b) == QDialogButtonBox.AcceptRole))
            deleteButton.click()

        QTimer.singleShot(1, clickOk)
        btn.click()

        # This is the important check that the feature is deleted
        self.assertEqual(0, len([f for f in self.vl_b.getFeatures()]))

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEqual(0, len([f for f in self.vl_link.getFeatures()]))

        self.assertEqual(self.table_view.model().rowCount(), 0)

    def test_list(self):
        """
        Simple check if several related items are shown
        """
        wrapper = self.createWrapper(self.vl_b)  # NOQA

        self.assertEqual(self.table_view.model().rowCount(), 4)

    @unittest.expectedFailure(os.environ.get('QT_VERSION', '5') == '4' and os.environ.get('TRAVIS_OS_NAME', '') == 'linux')  # It's probably not related to this variables at all, but that's the closest we can get to the real source of this problem at the moment...
    def test_add_feature(self):
        """
        Check if a new related feature is added
        """
        self.createWrapper(self.vl_a, '"name"=\'Douglas Adams\'')

        self.assertEqual(self.table_view.model().rowCount(), 0)

        self.vltools.setValues([None, 'The Hitchhiker\'s Guide to the Galaxy'])
        btn = self.widget.findChild(QToolButton, 'mAddFeatureButton')
        btn.click()

        # Book entry has been created
        self.assertEqual(2, len([f for f in self.vl_b.getFeatures()]))

        # Link entry has been created
        self.assertEqual(5, len([f for f in self.vl_link.getFeatures()]))

        self.assertEqual(self.table_view.model().rowCount(), 1)

    def test_link_feature(self):
        """
        Check if an existing feature can be linked
        """
        wrapper = self.createWrapper(self.vl_a, '"name"=\'Douglas Adams\'')  # NOQA

        f = QgsFeature(self.vl_b.fields())
        f.setAttributes([self.vl_b.dataProvider().defaultValueClause(0), 'The Hitchhiker\'s Guide to the Galaxy'])
        self.vl_b.addFeature(f)

        def choose_linked_feature():
            dlg = QApplication.activeModalWidget()
            dlg.setSelectedFeatures([f.id()])
            dlg.accept()

        btn = self.widget.findChild(QToolButton, 'mLinkFeatureButton')

        timer = QTimer()
        timer.setSingleShot(True)
        timer.setInterval(0)  # will run in the event loop as soon as it's processed when the dialog is opened
        timer.timeout.connect(choose_linked_feature)
        timer.start()

        btn.click()
        # magically the above code selects the feature here...

        link_feature = next(self.vl_link.getFeatures(QgsFeatureRequest().setFilterExpression('"fk_book"={}'.format(f[0]))))
        self.assertIsNotNone(link_feature[0])

        self.assertEqual(self.table_view.model().rowCount(), 1)

    def test_unlink_feature(self):
        """
        Check if a linked feature can be unlinked
        """
        wrapper = self.createWrapper(self.vl_b)   # NOQA

        # All authors are listed
        self.assertEqual(self.table_view.model().rowCount(), 4)

        it = self.vl_a.getFeatures(
            QgsFeatureRequest().setFilterExpression('"name" IN (\'Richard Helm\', \'Ralph Johnson\')'))

        self.widget.featureSelectionManager().select([f.id() for f in it])

        self.assertEqual(2, self.widget.featureSelectionManager().selectedFeatureCount())

        btn = self.widget.findChild(QToolButton, 'mUnlinkFeatureButton')
        btn.click()

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEqual(2, len([f for f in self.vl_link.getFeatures()]))

        self.assertEqual(2, self.table_view.model().rowCount())

    def test_discover_relations(self):
        """
        Test the automatic discovery of relations
        """
        relations = self.relMgr.discoverRelations([], [self.vl_a, self.vl_b, self.vl_link])
        relations = {r.name(): r for r in relations}
        self.assertEqual({'books_authors_fk_book_fkey', 'books_authors_fk_author_fkey'}, set(relations.keys()))

        ba2b = relations['books_authors_fk_book_fkey']
        self.assertTrue(ba2b.isValid())
        self.assertEqual('books_authors', ba2b.referencingLayer().name())
        self.assertEqual('books', ba2b.referencedLayer().name())
        self.assertEqual([0], ba2b.referencingFields())
        self.assertEqual([0], ba2b.referencedFields())

        ba2a = relations['books_authors_fk_author_fkey']
        self.assertTrue(ba2a.isValid())
        self.assertEqual('books_authors', ba2a.referencingLayer().name())
        self.assertEqual('authors', ba2a.referencedLayer().name())
        self.assertEqual([1], ba2a.referencingFields())
        self.assertEqual([0], ba2a.referencedFields())

        self.assertEqual([], self.relMgr.discoverRelations([self.rel_a, self.rel_b], [self.vl_a, self.vl_b, self.vl_link]))
        self.assertEqual(1, len(self.relMgr.discoverRelations([], [self.vl_a, self.vl_link])))

    def startTransaction(self):
        """
        Start a new transaction and set all layers into transaction mode.

        :return: None
        """
        lyrs = [self.vl_a, self.vl_b, self.vl_link]

        self.transaction = QgsTransaction.create(lyrs)
        self.transaction.begin()
        for l in lyrs:
            l.startEditing()

    def rollbackTransaction(self):
        """
        Rollback all changes done in this transaction.
        We always rollback and never commit to have the database in a pristine
        state at the end of each test.

        :return: None
        """
        lyrs = [self.vl_a, self.vl_b, self.vl_link]
        for l in lyrs:
            l.commitChanges()
        self.transaction.rollback()

    def createWrapper(self, layer, filter=None):
        """
        Basic setup of a relation widget wrapper.
        Will create a new wrapper and set its feature to the one and only book
        in the table.
        It will also assign some instance variables to help

         * self.widget The created widget
         * self.table_view The table view of the widget

        :return: The created wrapper
        """
        if layer == self.vl_b:
            relation = self.rel_b
            nmrel = self.rel_a
        else:
            relation = self.rel_a
            nmrel = self.rel_b

        self.wrapper = QgsRelationWidgetWrapper(layer, relation)
        self.wrapper.setConfig({'nm-rel': nmrel.id()})
        context = QgsAttributeEditorContext()
        context.setVectorLayerTools(self.vltools)
        self.wrapper.setContext(context)

        self.widget = self.wrapper.widget()
        self.widget.show()

        request = QgsFeatureRequest()
        if filter:
            request.setFilterExpression(filter)
        book = next(layer.getFeatures(request))
        self.wrapper.setFeature(book)

        self.table_view = self.widget.findChild(QTableView)
        return self.wrapper
Exemplo n.º 3
0
class TestQgsRelationEditWidget(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        """
        Setup the involved layers and relations for a n:m relation
        :return:
        """
        cls.mapCanvas = QgsMapCanvas()
        QgsGui.editorWidgetRegistry().initEditors(cls.mapCanvas)
        cls.dbconn = 'service=\'qgis_test\''
        if 'QGIS_PGTEST_DB' in os.environ:
            cls.dbconn = os.environ['QGIS_PGTEST_DB']
        # Create test layer
        cls.vl_books = QgsVectorLayer(
            cls.dbconn +
            ' sslmode=disable key=\'pk\' table="qgis_test"."books" sql=',
            'books', 'postgres')
        cls.vl_authors = QgsVectorLayer(
            cls.dbconn +
            ' sslmode=disable key=\'pk\' table="qgis_test"."authors" sql=',
            'authors', 'postgres')
        cls.vl_editors = QgsVectorLayer(
            cls.dbconn +
            ' sslmode=disable key=\'fk_book,fk_author\' table="qgis_test"."editors" sql=',
            'editors', 'postgres')
        cls.vl_link_books_authors = QgsVectorLayer(
            cls.dbconn +
            ' sslmode=disable key=\'pk\' table="qgis_test"."books_authors" sql=',
            'books_authors', 'postgres')

        QgsProject.instance().addMapLayer(cls.vl_books)
        QgsProject.instance().addMapLayer(cls.vl_authors)
        QgsProject.instance().addMapLayer(cls.vl_editors)
        QgsProject.instance().addMapLayer(cls.vl_link_books_authors)

        cls.relMgr = QgsProject.instance().relationManager()

        cls.rel_a = QgsRelation()
        cls.rel_a.setReferencingLayer(cls.vl_link_books_authors.id())
        cls.rel_a.setReferencedLayer(cls.vl_authors.id())
        cls.rel_a.addFieldPair('fk_author', 'pk')
        cls.rel_a.setId('rel_a')
        assert (cls.rel_a.isValid())
        cls.relMgr.addRelation(cls.rel_a)

        cls.rel_b = QgsRelation()
        cls.rel_b.setReferencingLayer(cls.vl_link_books_authors.id())
        cls.rel_b.setReferencedLayer(cls.vl_books.id())
        cls.rel_b.addFieldPair('fk_book', 'pk')
        cls.rel_b.setId('rel_b')
        assert (cls.rel_b.isValid())
        cls.relMgr.addRelation(cls.rel_b)

        # Our mock QgsVectorLayerTools, that allow injecting data where user input is expected
        cls.vltools = VlTools()

        assert (cls.vl_authors.isValid())
        assert (cls.vl_books.isValid())
        assert (cls.vl_editors.isValid())
        assert (cls.vl_link_books_authors.isValid())

    def setUp(self):
        self.startTransaction()

    def tearDown(self):
        self.rollbackTransaction()
        del self.transaction

    def test_delete_feature(self):
        """
        Check if a feature can be deleted properly
        """
        self.createWrapper(self.vl_authors, '"name"=\'Erich Gamma\'')

        self.assertEqual(self.table_view.model().rowCount(), 1)

        self.assertEqual(1, len([f for f in self.vl_books.getFeatures()]))

        fid = next(
            self.vl_books.getFeatures(QgsFeatureRequest().setFilterExpression(
                '"name"=\'Design Patterns. Elements of Reusable Object-Oriented Software\''
            ))).id()

        self.widget.featureSelectionManager().select([fid])

        btn = self.widget.findChild(QToolButton, 'mDeleteFeatureButton')

        def clickOk():
            # Click the "Delete features" button on the confirmation message
            # box
            widget = self.widget.findChild(QMessageBox)
            buttonBox = widget.findChild(QDialogButtonBox)
            deleteButton = next(
                (b for b in buttonBox.buttons()
                 if buttonBox.buttonRole(b) == QDialogButtonBox.AcceptRole))
            deleteButton.click()

        QTimer.singleShot(1, clickOk)
        btn.click()

        # This is the important check that the feature is deleted
        self.assertEqual(0, len([f for f in self.vl_books.getFeatures()]))

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEqual(
            0, len([f for f in self.vl_link_books_authors.getFeatures()]))

        self.assertEqual(self.table_view.model().rowCount(), 0)

    def test_list(self):
        """
        Simple check if several related items are shown
        """
        wrapper = self.createWrapper(self.vl_books)  # NOQA

        self.assertEqual(self.table_view.model().rowCount(), 4)

    def test_add_feature(self):
        """
        Check if a new related feature is added
        """
        self.createWrapper(self.vl_authors, '"name"=\'Douglas Adams\'')

        self.assertEqual(self.table_view.model().rowCount(), 0)

        self.vltools.setValues([
            None, 'The Hitchhiker\'s Guide to the Galaxy', 'Sputnik Editions',
            1961
        ])
        btn = self.widget.findChild(QToolButton, 'mAddFeatureButton')
        btn.click()

        # Book entry has been created
        self.assertEqual(2, len([f for f in self.vl_books.getFeatures()]))

        # Link entry has been created
        self.assertEqual(
            5, len([f for f in self.vl_link_books_authors.getFeatures()]))

        self.assertEqual(self.table_view.model().rowCount(), 1)

    def test_link_feature(self):
        """
        Check if an existing feature can be linked
        """
        wrapper = self.createWrapper(self.vl_authors,
                                     '"name"=\'Douglas Adams\'')  # NOQA

        f = QgsFeature(self.vl_books.fields())
        f.setAttributes([
            self.vl_books.dataProvider().defaultValueClause(0),
            'The Hitchhiker\'s Guide to the Galaxy', 'Sputnik Editions', 1961
        ])
        self.vl_books.addFeature(f)

        btn = self.widget.findChild(QToolButton, 'mLinkFeatureButton')
        btn.click()

        dlg = self.widget.findChild(QDialog)
        dlg.setSelectedFeatures([f.id()])
        dlg.accept()

        # magically the above code selects the feature here...
        link_feature = next(
            self.vl_link_books_authors.getFeatures(
                QgsFeatureRequest().setFilterExpression('"fk_book"={}'.format(
                    f[0]))))
        self.assertIsNotNone(link_feature[0])

        self.assertEqual(self.table_view.model().rowCount(), 1)

    def test_unlink_feature(self):
        """
        Check if a linked feature can be unlinked
        """
        wrapper = self.createWrapper(self.vl_books)  # NOQA

        # All authors are listed
        self.assertEqual(self.table_view.model().rowCount(), 4)

        it = self.vl_authors.getFeatures(
            QgsFeatureRequest().setFilterExpression(
                '"name" IN (\'Richard Helm\', \'Ralph Johnson\')'))

        self.widget.featureSelectionManager().select([f.id() for f in it])

        self.assertEqual(
            2,
            self.widget.featureSelectionManager().selectedFeatureCount())

        btn = self.widget.findChild(QToolButton, 'mUnlinkFeatureButton')
        btn.click()

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEqual(
            2, len([f for f in self.vl_link_books_authors.getFeatures()]))

        self.assertEqual(2, self.table_view.model().rowCount())

    def test_discover_relations(self):
        """
        Test the automatic discovery of relations
        """
        relations = self.relMgr.discoverRelations(
            [], [self.vl_authors, self.vl_books, self.vl_link_books_authors])
        relations = {r.name(): r for r in relations}
        self.assertEqual(
            {'books_authors_fk_book_fkey', 'books_authors_fk_author_fkey'},
            set(relations.keys()))

        ba2b = relations['books_authors_fk_book_fkey']
        self.assertTrue(ba2b.isValid())
        self.assertEqual('books_authors', ba2b.referencingLayer().name())
        self.assertEqual('books', ba2b.referencedLayer().name())
        self.assertEqual([0], ba2b.referencingFields())
        self.assertEqual([0], ba2b.referencedFields())

        ba2a = relations['books_authors_fk_author_fkey']
        self.assertTrue(ba2a.isValid())
        self.assertEqual('books_authors', ba2a.referencingLayer().name())
        self.assertEqual('authors', ba2a.referencedLayer().name())
        self.assertEqual([1], ba2a.referencingFields())
        self.assertEqual([0], ba2a.referencedFields())

        self.assertEqual(
            [],
            self.relMgr.discoverRelations(
                [self.rel_a, self.rel_b],
                [self.vl_authors, self.vl_books, self.vl_link_books_authors]))
        self.assertEqual(
            1,
            len(
                self.relMgr.discoverRelations(
                    [], [self.vl_authors, self.vl_link_books_authors])))

        # composite keys relation
        relations = self.relMgr.discoverRelations(
            [], [self.vl_books, self.vl_editors])
        self.assertEqual(len(relations), 1)
        relation = relations[0]
        self.assertEqual('books_fk_editor_fkey', relation.name())
        self.assertTrue(relation.isValid())
        self.assertEqual('books', relation.referencingLayer().name())
        self.assertEqual('editors', relation.referencedLayer().name())
        self.assertEqual([2, 3], relation.referencingFields())
        self.assertEqual([0, 1], relation.referencedFields())

    def test_selection(self):

        fbook = QgsFeature(self.vl_books.fields())
        fbook.setAttributes([
            self.vl_books.dataProvider().defaultValueClause(0),
            'The Hitchhiker\'s Guide to the Galaxy', 'Sputnik Editions', 1961
        ])
        self.vl_books.addFeature(fbook)

        flink = QgsFeature(self.vl_link_books_authors.fields())
        flink.setAttributes([fbook.id(), 5])
        self.vl_link_books_authors.addFeature(flink)

        self.createWrapper(self.vl_authors, '"name"=\'Douglas Adams\'')

        self.zoomToButton = self.widget.findChild(QToolButton,
                                                  "mDeleteFeatureButton")
        self.assertTrue(self.zoomToButton)
        self.assertTrue(not self.zoomToButton.isEnabled())

        selectionMgr = self.widget.featureSelectionManager()
        self.assertTrue(selectionMgr)

        self.vl_books.select(fbook.id())
        self.assertEqual([fbook.id()], selectionMgr.selectedFeatureIds())
        self.assertTrue(self.zoomToButton.isEnabled())

        selectionMgr.deselect([fbook.id()])
        self.assertEqual([], selectionMgr.selectedFeatureIds())
        self.assertTrue(not self.zoomToButton.isEnabled())

        self.vl_books.select([1, fbook.id()])
        self.assertEqual([fbook.id()], selectionMgr.selectedFeatureIds())
        self.assertTrue(self.zoomToButton.isEnabled())

    def test_add_feature_geometry(self):
        """
        Test to add a feature with a geometry
        """
        vl_pipes = QgsVectorLayer(
            self.dbconn +
            ' sslmode=disable key=\'pk\' table="qgis_test"."pipes" (geom) sql=',
            'pipes', 'postgres')
        vl_leaks = QgsVectorLayer(
            self.dbconn +
            ' sslmode=disable key=\'pk\' table="qgis_test"."leaks" (geom) sql=',
            'leaks', 'postgres')
        vl_leaks.startEditing()

        QgsProject.instance().addMapLayer(vl_pipes)
        QgsProject.instance().addMapLayer(vl_leaks)

        self.assertEqual(vl_pipes.featureCount(), 2)
        self.assertEqual(vl_leaks.featureCount(), 3)

        rel = QgsRelation()
        rel.setReferencingLayer(vl_leaks.id())
        rel.setReferencedLayer(vl_pipes.id())
        rel.addFieldPair('pipe', 'id')
        rel.setId('rel_pipe_leak')
        self.assertTrue(rel.isValid())
        self.relMgr.addRelation(rel)

        # Mock vector layer tool to just set default value on created feature
        class DummyVlTools(QgsVectorLayerTools):
            def addFeature(self, layer, defaultValues, defaultGeometry):
                f = QgsFeature(layer.fields())
                for idx, value in defaultValues.items():
                    f.setAttribute(idx, value)
                f.setGeometry(defaultGeometry)
                ok = layer.addFeature(f)

                return ok, f

        wrapper = QgsRelationWidgetWrapper(vl_leaks, rel)
        context = QgsAttributeEditorContext()
        vltool = DummyVlTools()
        context.setVectorLayerTools(vltool)
        context.setMapCanvas(self.mapCanvas)
        cadDockWidget = QgsAdvancedDigitizingDockWidget(self.mapCanvas)
        context.setCadDockWidget(cadDockWidget)
        wrapper.setContext(context)
        widget = wrapper.widget()
        widget.show()
        pipe = next(vl_pipes.getFeatures())
        self.assertEqual(pipe.id(), 1)
        wrapper.setFeature(pipe)
        table_view = widget.findChild(QTableView)
        self.assertEqual(table_view.model().rowCount(), 1)

        btn = widget.findChild(QToolButton, 'mAddFeatureGeometryButton')
        self.assertTrue(btn.isVisible())
        self.assertTrue(btn.isEnabled())
        btn.click()
        self.assertTrue(self.mapCanvas.mapTool())
        feature = QgsFeature(vl_leaks.fields())
        feature.setGeometry(QgsGeometry.fromWkt('POINT(0 0.8)'))
        self.mapCanvas.mapTool().digitizingCompleted.emit(feature)
        self.assertEqual(table_view.model().rowCount(), 2)
        self.assertEqual(vl_leaks.featureCount(), 4)
        request = QgsFeatureRequest()
        request.addOrderBy("id", False)

        # get new created feature
        feat = next(vl_leaks.getFeatures('"id" is NULL'))
        self.assertTrue(feat.isValid())
        self.assertTrue(feat.geometry().equals(
            QgsGeometry.fromWkt('POINT(0 0.8)')))

        vl_leaks.rollBack()

    def startTransaction(self):
        """
        Start a new transaction and set all layers into transaction mode.

        :return: None
        """
        lyrs = [self.vl_authors, self.vl_books, self.vl_link_books_authors]

        self.transaction = QgsTransaction.create(lyrs)
        self.transaction.begin()
        for l in lyrs:
            l.startEditing()

    def rollbackTransaction(self):
        """
        Rollback all changes done in this transaction.
        We always rollback and never commit to have the database in a pristine
        state at the end of each test.

        :return: None
        """
        lyrs = [self.vl_authors, self.vl_books, self.vl_link_books_authors]
        for l in lyrs:
            l.commitChanges()
        self.transaction.rollback()

    def createWrapper(self, layer, filter=None):
        """
        Basic setup of a relation widget wrapper.
        Will create a new wrapper and set its feature to the one and only book
        in the table.
        It will also assign some instance variables to help

         * self.widget The created widget
         * self.table_view The table view of the widget

        :return: The created wrapper
        """
        if layer == self.vl_books:
            relation = self.rel_b
            nmrel = self.rel_a
        else:
            relation = self.rel_a
            nmrel = self.rel_b

        self.wrapper = QgsRelationWidgetWrapper(layer, relation)
        self.wrapper.setConfig({'nm-rel': nmrel.id()})
        context = QgsAttributeEditorContext()
        context.setMapCanvas(self.mapCanvas)
        context.setVectorLayerTools(self.vltools)
        self.wrapper.setContext(context)

        self.widget = self.wrapper.widget()
        self.widget.show()

        request = QgsFeatureRequest()
        if filter:
            request.setFilterExpression(filter)
        book = next(layer.getFeatures(request))
        self.wrapper.setFeature(book)

        self.table_view = self.widget.findChild(QTableView)
        return self.wrapper
Exemplo n.º 4
0
    def test_add_feature_geometry(self):
        """
        Test to add a feature with a geometry
        """
        vl_pipes = QgsVectorLayer(
            self.dbconn +
            ' sslmode=disable key=\'pk\' table="qgis_test"."pipes" (geom) sql=',
            'pipes', 'postgres')
        vl_leaks = QgsVectorLayer(
            self.dbconn +
            ' sslmode=disable key=\'pk\' table="qgis_test"."leaks" (geom) sql=',
            'leaks', 'postgres')
        vl_leaks.startEditing()

        QgsProject.instance().addMapLayer(vl_pipes)
        QgsProject.instance().addMapLayer(vl_leaks)

        self.assertEqual(vl_pipes.featureCount(), 2)
        self.assertEqual(vl_leaks.featureCount(), 3)

        rel = QgsRelation()
        rel.setReferencingLayer(vl_leaks.id())
        rel.setReferencedLayer(vl_pipes.id())
        rel.addFieldPair('pipe', 'id')
        rel.setId('rel_pipe_leak')
        self.assertTrue(rel.isValid())
        self.relMgr.addRelation(rel)

        # Mock vector layer tool to just set default value on created feature
        class DummyVlTools(QgsVectorLayerTools):
            def addFeature(self, layer, defaultValues, defaultGeometry):
                f = QgsFeature(layer.fields())
                for idx, value in defaultValues.items():
                    f.setAttribute(idx, value)
                f.setGeometry(defaultGeometry)
                ok = layer.addFeature(f)

                return ok, f

        wrapper = QgsRelationWidgetWrapper(vl_leaks, rel)
        context = QgsAttributeEditorContext()
        vltool = DummyVlTools()
        context.setVectorLayerTools(vltool)
        context.setMapCanvas(self.mapCanvas)
        cadDockWidget = QgsAdvancedDigitizingDockWidget(self.mapCanvas)
        context.setCadDockWidget(cadDockWidget)
        wrapper.setContext(context)
        widget = wrapper.widget()
        widget.show()
        pipe = next(vl_pipes.getFeatures())
        self.assertEqual(pipe.id(), 1)
        wrapper.setFeature(pipe)
        table_view = widget.findChild(QTableView)
        self.assertEqual(table_view.model().rowCount(), 1)

        btn = widget.findChild(QToolButton, 'mAddFeatureGeometryButton')
        self.assertTrue(btn.isVisible())
        self.assertTrue(btn.isEnabled())
        btn.click()
        self.assertTrue(self.mapCanvas.mapTool())
        feature = QgsFeature(vl_leaks.fields())
        feature.setGeometry(QgsGeometry.fromWkt('POINT(0 0.8)'))
        self.mapCanvas.mapTool().digitizingCompleted.emit(feature)
        self.assertEqual(table_view.model().rowCount(), 2)
        self.assertEqual(vl_leaks.featureCount(), 4)
        request = QgsFeatureRequest()
        request.addOrderBy("id", False)

        # get new created feature
        feat = next(vl_leaks.getFeatures('"id" is NULL'))
        self.assertTrue(feat.isValid())
        self.assertTrue(feat.geometry().equals(
            QgsGeometry.fromWkt('POINT(0 0.8)')))

        vl_leaks.rollBack()
Exemplo n.º 5
0
class TestQgsRelationEditWidget(TestCase):

    @classmethod
    def setUpClass(cls):
        """
        Setup the involved layers and relations for a n:m relation
        :return:
        """
        QgsEditorWidgetRegistry.initEditors()
        cls.dbconn = u'dbname=\'qgis_test\' host=localhost port=5432 user=\'postgres\' password=\'postgres\''
        if 'QGIS_PGTEST_DB' in os.environ:
            cls.dbconn = os.environ['QGIS_PGTEST_DB']
        # Create test layer
        cls.vl_b = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."books" sql=', 'test', 'postgres')
        cls.vl_a = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."authors" sql=', 'test', 'postgres')
        cls.vl_link = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."books_authors" sql=', 'test', 'postgres')

        QgsMapLayerRegistry.instance().addMapLayer(cls.vl_b)
        QgsMapLayerRegistry.instance().addMapLayer(cls.vl_a)
        QgsMapLayerRegistry.instance().addMapLayer(cls.vl_link)

        relMgr = QgsProject.instance().relationManager()

        cls.rel_a = QgsRelation()
        cls.rel_a.setReferencingLayer(cls.vl_link.id())
        cls.rel_a.setReferencedLayer(cls.vl_a.id())
        cls.rel_a.addFieldPair('fk_author', 'pk')
        cls.rel_a.setRelationId('rel_a')
        assert(cls.rel_a.isValid())
        relMgr.addRelation(cls.rel_a)

        cls.rel_b = QgsRelation()
        cls.rel_b.setReferencingLayer(cls.vl_link.id())
        cls.rel_b.setReferencedLayer(cls.vl_b.id())
        cls.rel_b.addFieldPair('fk_book', 'pk')
        cls.rel_b.setRelationId('rel_b')
        assert(cls.rel_b.isValid())
        relMgr.addRelation(cls.rel_b)

        # Our mock QgsVectorLayerTools, that allow to inject data where user input is expected
        cls.vltools = VlTools()

        assert(cls.vl_a.isValid())
        assert(cls.vl_b.isValid())
        assert(cls.vl_link.isValid())

    def setUp(self):
        self.startTransaction()

    def tearDown(self):
        self.rollbackTransaction()

    def test_delete_feature(self):
        """
        Check if a feature can be deleted properly
        """
        self.createWrapper(self.vl_a, '"name"=\'Erich Gamma\'')

        self.assertEquals(self.table_view.model().rowCount(), 1)

        self.assertEquals(1, len([f for f in self.vl_b.getFeatures()]))

        fid = self.vl_b.getFeatures(QgsFeatureRequest().setFilterExpression('"name"=\'Design Patterns. Elements of Reusable Object-Oriented Software\'')).next().id()

        self.widget.featureSelectionManager().select([fid])

        btn = self.widget.findChild(QToolButton, 'mDeleteFeatureButton')
        btn.click()

        # This is the important check that the feature is deleted
        self.assertEquals(0, len([f for f in self.vl_b.getFeatures()]))

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEquals(0, len([f for f in self.vl_link.getFeatures()]))

        self.assertEquals(self.table_view.model().rowCount(), 0)

    def test_list(self):
        """
        Simple check if several related items are shown
        """
        wrapper = self.createWrapper(self.vl_b)

        self.assertEquals(self.table_view.model().rowCount(), 4)

    @expectedFailure
    def test_add_feature(self):
        """
        Check if a new related feature is added
        """
        self.createWrapper(self.vl_a, '"name"=\'Douglas Adams\'')

        self.assertEquals(self.table_view.model().rowCount(), 0)

        self.vltools.setValues([None, 'The Hitchhiker\'s Guide to the Galaxy'])
        btn = self.widget.findChild(QToolButton, 'mAddFeatureButton')
        btn.click()

        # Book entry has been created
        self.assertEquals(2, len([f for f in self.vl_b.getFeatures()]))

        # Link entry has been created
        self.assertEquals(5, len([f for f in self.vl_link.getFeatures()]))

        self.assertEquals(self.table_view.model().rowCount(), 1)

    def test_link_feature(self):
        """
        Check if an existing feature can be linked
        """
        wrapper = self.createWrapper(self.vl_a, '"name"=\'Douglas Adams\'')

        f = QgsFeature(self.vl_b.fields())
        f.setAttributes([self.vl_b.dataProvider().defaultValue(0), 'The Hitchhiker\'s Guide to the Galaxy'])
        self.vl_b.addFeature(f)

        def choose_linked_feature():
            dlg = QApplication.activeModalWidget()
            dlg.setSelectedFeatures([f.id()])
            dlg.accept()

        btn = self.widget.findChild(QToolButton, 'mLinkFeatureButton')

        timer = QTimer()
        timer.setSingleShot(True)
        timer.setInterval(0) # will run in the event loop as soon as it's processed when the dialog is opened
        timer.timeout.connect(choose_linked_feature)
        timer.start()

        btn.click()
        # magically the above code selects the feature here...

        link_feature = self.vl_link.getFeatures(QgsFeatureRequest().setFilterExpression('"fk_book"={}'.format(f[0]))).next()
        self.assertIsNotNone(link_feature[0])

        self.assertEquals(self.table_view.model().rowCount(), 1)

    @expectedFailure
    def test_unlink_feature(self):
        """
        Check if a linked feature can be unlinked
        """
        wrapper = self.createWrapper(self.vl_b)
        wdg = wrapper.widget()

        # All authors are listed
        self.assertEquals(self.table_view.model().rowCount(), 4)

        it = self.vl_a.getFeatures(
            QgsFeatureRequest().setFilterExpression('"name" IN (\'Richard Helm\', \'Ralph Johnson\')'))

        self.widget.featureSelectionManager().select([f.id() for f in it])

        btn = self.widget.findChild(QToolButton, 'mUnlinkFeatureButton')
        btn.click()

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEquals(2, len([f for f in self.vl_link.getFeatures()]))

        self.assertEquals(2, self.table_view.model().rowCount())

    def startTransaction(self):
        """
        Start a new transaction and set all layers into transaction mode.

        :return: None
        """
        lyrs = [self.vl_a, self.vl_b, self.vl_link]

        self.transaction = QgsTransaction.create([l.id() for l in lyrs])
        self.transaction.begin()
        for l in lyrs:
            l.startEditing()

    def rollbackTransaction(self):
        """
        Rollback all changes done in this transaction.
        We always rollback and never commit to have the database in a pristine
        state at the end of each test.

        :return: None
        """
        lyrs = [self.vl_a, self.vl_b, self.vl_link]
        for l in lyrs:
            l.commitChanges()
        self.transaction.rollback()

    def createWrapper(self, layer, filter=None):
        """
        Basic setup of a relation widget wrapper.
        Will create a new wrapper and set its feature to the one and only book
        in the table.
        It will also assign some instance variables to help

         * self.widget The created widget
         * self.table_view The table view of the widget

        :return: The created wrapper
        """
        if layer == self.vl_b:
            relation = self.rel_b
            nmrel = self.rel_a
        else:
            relation = self.rel_a
            nmrel = self.rel_b

        parent = QWidget()
        self.wrapper = QgsRelationWidgetWrapper(layer, relation)
        self.wrapper.setConfig({'nm-rel': nmrel.id()})
        context = QgsAttributeEditorContext()
        context.setVectorLayerTools(self.vltools)
        self.wrapper.setContext(context)

        self.widget = self.wrapper.widget()
        self.widget.show()

        request = QgsFeatureRequest()
        if filter:
            request.setFilterExpression(filter)
        book = layer.getFeatures(request).next()
        self.wrapper.setFeature(book)

        self.table_view = self.widget.findChild(QTableView)
        return self.wrapper
class TestQgsRelationEditWidget(TestCase):

    @classmethod
    def setUpClass(cls):
        """
        Setup the involved layers and relations for a n:m relation
        :return:
        """
        QgsEditorWidgetRegistry.initEditors()
        cls.dbconn = u'dbname=\'qgis_test\' host=localhost port=5432 user=\'postgres\' password=\'postgres\''
        if 'QGIS_PGTEST_DB' in os.environ:
            cls.dbconn = os.environ['QGIS_PGTEST_DB']
        # Create test layer
        cls.vl_b = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."books" sql=', 'test', 'postgres')
        cls.vl_a = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."authors" sql=', 'test', 'postgres')
        cls.vl_link = QgsVectorLayer(cls.dbconn + ' sslmode=disable key=\'pk\' table="qgis_test"."books_authors" sql=', 'test', 'postgres')

        QgsMapLayerRegistry.instance().addMapLayer(cls.vl_b)
        QgsMapLayerRegistry.instance().addMapLayer(cls.vl_a)
        QgsMapLayerRegistry.instance().addMapLayer(cls.vl_link)

        relMgr = QgsProject.instance().relationManager()

        cls.rel_a = QgsRelation()
        cls.rel_a.setReferencingLayer(cls.vl_link.id())
        cls.rel_a.setReferencedLayer(cls.vl_a.id())
        cls.rel_a.addFieldPair('fk_author', 'pk')
        cls.rel_a.setRelationId('rel_a')
        assert(cls.rel_a.isValid())
        relMgr.addRelation(cls.rel_a)

        cls.rel_b = QgsRelation()
        cls.rel_b.setReferencingLayer(cls.vl_link.id())
        cls.rel_b.setReferencedLayer(cls.vl_b.id())
        cls.rel_b.addFieldPair('fk_book', 'pk')
        cls.rel_b.setRelationId('rel_b')
        assert(cls.rel_b.isValid())
        relMgr.addRelation(cls.rel_b)

        # Our mock QgsVectorLayerTools, that allow injecting data where user input is expected
        cls.vltools = VlTools()

        assert(cls.vl_a.isValid())
        assert(cls.vl_b.isValid())
        assert(cls.vl_link.isValid())

    def setUp(self):
        self.startTransaction()

    def tearDown(self):
        self.rollbackTransaction()

    def test_delete_feature(self):
        """
        Check if a feature can be deleted properly
        """
        self.createWrapper(self.vl_a, '"name"=\'Erich Gamma\'')

        self.assertEquals(self.table_view.model().rowCount(), 1)

        self.assertEquals(1, len([f for f in self.vl_b.getFeatures()]))

        fid = self.vl_b.getFeatures(QgsFeatureRequest().setFilterExpression('"name"=\'Design Patterns. Elements of Reusable Object-Oriented Software\'')).next().id()

        self.widget.featureSelectionManager().select([fid])

        btn = self.widget.findChild(QToolButton, 'mDeleteFeatureButton')
        btn.click()

        # This is the important check that the feature is deleted
        self.assertEquals(0, len([f for f in self.vl_b.getFeatures()]))

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEquals(0, len([f for f in self.vl_link.getFeatures()]))

        self.assertEquals(self.table_view.model().rowCount(), 0)

    def test_list(self):
        """
        Simple check if several related items are shown
        """
        wrapper = self.createWrapper(self.vl_b)

        self.assertEquals(self.table_view.model().rowCount(), 4)

    @expectedFailure
    def test_add_feature(self):
        """
        Check if a new related feature is added
        """
        self.createWrapper(self.vl_a, '"name"=\'Douglas Adams\'')

        self.assertEquals(self.table_view.model().rowCount(), 0)

        self.vltools.setValues([None, 'The Hitchhiker\'s Guide to the Galaxy'])
        btn = self.widget.findChild(QToolButton, 'mAddFeatureButton')
        btn.click()

        # Book entry has been created
        self.assertEquals(2, len([f for f in self.vl_b.getFeatures()]))

        # Link entry has been created
        self.assertEquals(5, len([f for f in self.vl_link.getFeatures()]))

        self.assertEquals(self.table_view.model().rowCount(), 1)

    def test_link_feature(self):
        """
        Check if an existing feature can be linked
        """
        wrapper = self.createWrapper(self.vl_a, '"name"=\'Douglas Adams\'')

        f = QgsFeature(self.vl_b.fields())
        f.setAttributes([self.vl_b.dataProvider().defaultValue(0), 'The Hitchhiker\'s Guide to the Galaxy'])
        self.vl_b.addFeature(f)

        def choose_linked_feature():
            dlg = QApplication.activeModalWidget()
            dlg.setSelectedFeatures([f.id()])
            dlg.accept()

        btn = self.widget.findChild(QToolButton, 'mLinkFeatureButton')

        timer = QTimer()
        timer.setSingleShot(True)
        timer.setInterval(0) # will run in the event loop as soon as it's processed when the dialog is opened
        timer.timeout.connect(choose_linked_feature)
        timer.start()

        btn.click()
        # magically the above code selects the feature here...

        link_feature = self.vl_link.getFeatures(QgsFeatureRequest().setFilterExpression('"fk_book"={}'.format(f[0]))).next()
        self.assertIsNotNone(link_feature[0])

        self.assertEquals(self.table_view.model().rowCount(), 1)

    @expectedFailure
    def test_unlink_feature(self):
        """
        Check if a linked feature can be unlinked
        """
        wrapper = self.createWrapper(self.vl_b)
        wdg = wrapper.widget()

        # All authors are listed
        self.assertEquals(self.table_view.model().rowCount(), 4)

        it = self.vl_a.getFeatures(
            QgsFeatureRequest().setFilterExpression('"name" IN (\'Richard Helm\', \'Ralph Johnson\')'))

        self.widget.featureSelectionManager().select([f.id() for f in it])

        btn = self.widget.findChild(QToolButton, 'mUnlinkFeatureButton')
        btn.click()

        # This is actually more checking that the database on delete action is properly set on the relation
        self.assertEquals(2, len([f for f in self.vl_link.getFeatures()]))

        self.assertEquals(2, self.table_view.model().rowCount())

    def startTransaction(self):
        """
        Start a new transaction and set all layers into transaction mode.

        :return: None
        """
        lyrs = [self.vl_a, self.vl_b, self.vl_link]

        self.transaction = QgsTransaction.create([l.id() for l in lyrs])
        self.transaction.begin()
        for l in lyrs:
            l.startEditing()

    def rollbackTransaction(self):
        """
        Rollback all changes done in this transaction.
        We always rollback and never commit to have the database in a pristine
        state at the end of each test.

        :return: None
        """
        lyrs = [self.vl_a, self.vl_b, self.vl_link]
        for l in lyrs:
            l.commitChanges()
        self.transaction.rollback()

    def createWrapper(self, layer, filter=None):
        """
        Basic setup of a relation widget wrapper.
        Will create a new wrapper and set its feature to the one and only book
        in the table.
        It will also assign some instance variables to help

         * self.widget The created widget
         * self.table_view The table view of the widget

        :return: The created wrapper
        """
        if layer == self.vl_b:
            relation = self.rel_b
            nmrel = self.rel_a
        else:
            relation = self.rel_a
            nmrel = self.rel_b

        parent = QWidget()
        self.wrapper = QgsRelationWidgetWrapper(layer, relation)
        self.wrapper.setConfig({'nm-rel': nmrel.id()})
        context = QgsAttributeEditorContext()
        context.setVectorLayerTools(self.vltools)
        self.wrapper.setContext(context)

        self.widget = self.wrapper.widget()
        self.widget.show()

        request = QgsFeatureRequest()
        if filter:
            request.setFilterExpression(filter)
        book = layer.getFeatures(request).next()
        self.wrapper.setFeature(book)

        self.table_view = self.widget.findChild(QTableView)
        return self.wrapper