Add a model for schemas from a database connection

python/core/auto_generated/qgsdatabaseschemamodel.sip.in

@@ -0,0 +1,69 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsdatabaseschemamodel.h                                    *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+class QgsDatabaseSchemaModel : QAbstractItemModel
+{
+%Docstring
+A model containing schemas from a database connection.
+
+This class does not automatically subscribe to database updates. Schemas are queried
+from the database initially upon model construction. In order
+to update the listed schemas, QgsDatabaseSchemaModel.refresh() must be manually
+called.
+
+.. versionadded:: 3.14
+%End
+
+%TypeHeaderCode
+#include "qgsdatabaseschemamodel.h"
+%End
+  public:
+
+    explicit QgsDatabaseSchemaModel( const QString &provider, const QString &connection, QObject *parent /TransferThis/ = 0 );
+%Docstring
+Constructor for QgsDatabaseSchemaModel, for the specified ``provider`` and ``connection`` name.
+
+.. warning::
+
+   The ``provider`` must support the connection API methods in its QgsProviderMetadata implementation
+   in order for the model to work correctly.
+%End
+
+    explicit QgsDatabaseSchemaModel( QgsAbstractDatabaseProviderConnection *connection /Transfer/, QObject *parent /TransferThis/ = 0 );
+
+    virtual QModelIndex parent( const QModelIndex &child ) const;
+
+    virtual int rowCount( const QModelIndex &parent = QModelIndex() ) const;
+
+    virtual int columnCount( const QModelIndex &parent = QModelIndex() ) const;
+
+    virtual QVariant data( const QModelIndex &index, int role = Qt::DisplayRole ) const;
+
+    virtual QModelIndex index( int row, int column, const QModelIndex &parent ) const;
+
+
+  public slots:
+
+    void refresh();
+%Docstring
+Refreshes the schema list by querying the underlying connection.
+%End
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsdatabaseschemamodel.h                                    *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

python/core/core_auto.sip

@@ -36,6 +36,7 @@
 %Include auto_generated/qgscoordinatetransformcontext.sip
 %Include auto_generated/qgscredentials.sip
 %Include auto_generated/qgsdartmeasurement.sip
+%Include auto_generated/qgsdatabaseschemamodel.sip
 %Include auto_generated/qgsdatadefinedsizelegend.sip
 %Include auto_generated/qgsdataitem.sip
 %Include auto_generated/qgsdataitemprovider.sip

src/core/CMakeLists.txt

@@ -227,6 +227,7 @@ SET(QGIS_CORE_SRCS
   qgscoordinateutils.cpp
   qgscredentials.cpp
   qgsdartmeasurement.cpp
+  qgsdatabaseschemamodel.cpp
   qgsdatadefinedsizelegend.cpp
   qgsdataitem.cpp
   qgsdataitemprovider.cpp
@@ -727,6 +728,7 @@ SET(QGIS_CORE_HDRS
   qgscoordinateutils.h
   qgscredentials.h
   qgsdartmeasurement.h
+  qgsdatabaseschemamodel.h
   qgsdatadefinedsizelegend.h
   qgsdataitem.h
   qgsdataitemprovider.h

src/core/qgsdatabaseschemamodel.cpp

@@ -0,0 +1,120 @@
+/***************************************************************************
+   qgsdatabaseschemamodel.cpp
+    --------------------------------------
+   Date                 : March 2020
+   Copyright            : (C) 2020 Nyall Dawson
+   Email                : nyall dot dawson at gmail dot com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************/
+#include "qgsdatabaseschemamodel.h"
+#include "qgsproviderregistry.h"
+#include "qgsprovidermetadata.h"
+#include "qgsabstractdatabaseproviderconnection.h"
+
+QgsDatabaseSchemaModel::QgsDatabaseSchemaModel( const QString &provider, const QString &connection, QObject *parent )
+  : QAbstractItemModel( parent )
+{
+  QgsProviderMetadata *metadata = QgsProviderRegistry::instance()->providerMetadata( provider );
+  Q_ASSERT( metadata );
+
+  mConnection.reset( dynamic_cast<QgsAbstractDatabaseProviderConnection *>( metadata->createConnection( connection ) ) );
+  Q_ASSERT( mConnection );
+  init();
+}
+
+QgsDatabaseSchemaModel::QgsDatabaseSchemaModel( QgsAbstractDatabaseProviderConnection *connection, QObject *parent )
+  : QAbstractItemModel( parent )
+  , mConnection( connection )
+{
+  Q_ASSERT( mConnection );
+  init();
+}
+
+void QgsDatabaseSchemaModel::init()
+{
+  Q_ASSERT( mConnection->capabilities() & QgsAbstractDatabaseProviderConnection::Capability::Schemas );
+  mSchemas = mConnection->schemas();
+}
+
+QModelIndex QgsDatabaseSchemaModel::parent( const QModelIndex &child ) const
+{
+  Q_UNUSED( child )
+  return QModelIndex();
+}
+
+
+int QgsDatabaseSchemaModel::rowCount( const QModelIndex &parent ) const
+{
+  if ( parent.isValid() )
+    return 0;
+
+  return mSchemas.count();
+}
+
+int QgsDatabaseSchemaModel::columnCount( const QModelIndex &parent ) const
+{
+  Q_UNUSED( parent )
+  return 1;
+}
+
+
+QVariant QgsDatabaseSchemaModel::data( const QModelIndex &index, int role ) const
+{
+  if ( !index.isValid() )
+    return QVariant();
+
+  const QString schemaName = mSchemas.value( index.row() );
+  switch ( role )
+  {
+    case Qt::DisplayRole:
+    case Qt::ToolTipRole:
+    {
+      return schemaName;
+    }
+  }
+
+  return QVariant();
+}
+
+QModelIndex QgsDatabaseSchemaModel::index( int row, int column, const QModelIndex &parent ) const
+{
+  if ( hasIndex( row, column, parent ) )
+  {
+    return createIndex( row, column, row );
+  }
+
+  return QModelIndex();
+}
+
+void QgsDatabaseSchemaModel::refresh()
+{
+  const QStringList newSchemas = mConnection->schemas();
+  const QStringList oldSchemas = mSchemas;
+
+  for ( const QString &oldSchema : oldSchemas )
+  {
+    if ( !newSchemas.contains( oldSchema ) )
+    {
+      int r = mSchemas.indexOf( oldSchema );
+      beginRemoveRows( QModelIndex(), r, r );
+      mSchemas.removeAt( r );
+      endRemoveRows();
+    }
+  }
+
+  for ( const QString &newSchema : newSchemas )
+  {
+    if ( !mSchemas.contains( newSchema ) )
+    {
+      beginInsertRows( QModelIndex(), mSchemas.count(), mSchemas.count() );
+      mSchemas.append( newSchema );
+      endInsertRows();
+    }
+  }
+}

src/core/qgsdatabaseschemamodel.h

@@ -0,0 +1,78 @@
+/***************************************************************************
+   qgsdatabaseschemamodel.h
+    --------------------------------------
+   Date                 : March 2020
+   Copyright            : (C) 2020 Nyall Dawson
+   Email                : nyall dot dawson at gmail dot com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************/
+
+#ifndef QGSDATABASESCHEMAMODEL_H
+#define QGSDATABASESCHEMAMODEL_H
+
+#include <QAbstractItemModel>
+#include <QSortFilterProxyModel>
+#include <QStringList>
+#include <memory>
+
+#include "qgis_core.h"
+#include "qgis_sip.h"
+
+class QgsProviderMetadata;
+class QgsAbstractDatabaseProviderConnection;
+
+/**
+ * \ingroup core
+ * \class QgsDatabaseSchemaModel
+ * \brief A model containing schemas from a database connection.
+ *
+ * This class does not automatically subscribe to database updates. Schemas are queried
+ * from the database initially upon model construction. In order
+ * to update the listed schemas, QgsDatabaseSchemaModel::refresh() must be manually
+ * called.
+ *
+ * \since QGIS 3.14
+ */
+class CORE_EXPORT QgsDatabaseSchemaModel : public QAbstractItemModel
+{
+    Q_OBJECT
+
+  public:
+
+    /**
+     * Constructor for QgsDatabaseSchemaModel, for the specified \a provider and \a connection name.
+     *
+     * \warning The \a provider must support the connection API methods in its QgsProviderMetadata implementation
+     * in order for the model to work correctly.
+     */
+    explicit QgsDatabaseSchemaModel( const QString &provider, const QString &connection, QObject *parent SIP_TRANSFERTHIS = nullptr );
+
+    explicit QgsDatabaseSchemaModel( QgsAbstractDatabaseProviderConnection *connection SIP_TRANSFER, QObject *parent SIP_TRANSFERTHIS = nullptr );
+
+    // QAbstractItemModel interface
+    QModelIndex parent( const QModelIndex &child ) const override;
+    int rowCount( const QModelIndex &parent = QModelIndex() ) const override;
+    int columnCount( const QModelIndex &parent = QModelIndex() ) const override;
+    QVariant data( const QModelIndex &index, int role = Qt::DisplayRole ) const override;
+    QModelIndex index( int row, int column, const QModelIndex &parent ) const override;
+
+  public slots:
+
+    /**
+     * Refreshes the schema list by querying the underlying connection.
+     */
+    void refresh();
+
+  private:
+    void init();
+    std::unique_ptr< QgsAbstractDatabaseProviderConnection > mConnection;
+    QStringList mSchemas;
+};
+
+#endif // QGSDATABASESCHEMAMODEL_H

tests/src/python/CMakeLists.txt

@@ -186,7 +186,6 @@ ADD_PYTHON_TEST(PyQgsProjectionSelectionWidgets test_qgsprojectionselectionwidge
 ADD_PYTHON_TEST(PyQgsProjectMetadata test_qgsprojectmetadata.py)
 ADD_PYTHON_TEST(PyQgsPropertyOverrideButton test_qgspropertyoverridebutton.py)
 ADD_PYTHON_TEST(PyQgsProviderConnectionModel test_qgsproviderconnectionmodel.py)
-ADD_PYTHON_TEST(PyQgsProviderConnectionPostgres test_qgsproviderconnection_postgres.py)
 ADD_PYTHON_TEST(PyQgsProviderConnectionGpkg test_qgsproviderconnection_ogr_gpkg.py)
 ADD_PYTHON_TEST(TestQgsRandomMarkerSymbolLayer test_qgsrandommarkersymbollayer.py)
 ADD_PYTHON_TEST(PyQgsRange test_qgsrange.py)
@@ -304,6 +303,8 @@ IF (ENABLE_PGTEST)
   ADD_PYTHON_TEST(PyQgsAuthManagerPasswordPostgresTest test_authmanager_password_postgres.py)
   ADD_PYTHON_TEST(PyQgsAuthManagerOgrPostgresTest test_authmanager_ogr_postgres.py)
   ADD_PYTHON_TEST(PyQgsDbManagerPostgis test_db_manager_postgis.py)
+  ADD_PYTHON_TEST(PyQgsDatabaseSchemaModel test_qgsdatabaseschemamodel.py)
+  ADD_PYTHON_TEST(PyQgsProviderConnectionPostgres test_qgsproviderconnection_postgres.py)
 ENDIF (ENABLE_PGTEST)
 
 IF (ENABLE_MSSQLTEST)

tests/src/python/test_qgsdatabaseschemamodel.py

@@ -0,0 +1,115 @@
+# -*- coding: utf-8 -*-
+"""QGIS Unit tests for QgsDatabaseSchemaModel
+
+.. note:: This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+"""
+__author__ = 'Nyall Dawson'
+__date__ = '07/03/2020'
+__copyright__ = 'Copyright 2020, The QGIS Project'
+# This will get replaced with a git SHA1 when you do a git archive
+__revision__ = '$Format:%H$'
+
+import os
+from qgis.core import (
+    QgsDatabaseSchemaModel,
+    QgsProviderRegistry,
+)
+from qgis.PyQt.QtCore import (
+    QCoreApplication,
+    QModelIndex,
+    Qt
+)
+from qgis.testing import unittest, start_app
+
+
+class TestPyQgsDatabaseSchemaModel(unittest.TestCase):
+
+    # Provider test cases must define the string URI for the test
+    uri = ''
+    # Provider test cases must define the provider name (e.g. "postgres" or "ogr")
+    providerKey = 'postgres'
+
+    @classmethod
+    def setUpClass(cls):
+        """Run before all tests"""
+
+        QCoreApplication.setOrganizationName("QGIS_Test")
+        QCoreApplication.setOrganizationDomain(cls.__name__)
+        QCoreApplication.setApplicationName(cls.__name__)
+        start_app()
+        cls.postgres_conn = "service='qgis_test'"
+        if 'QGIS_PGTEST_DB' in os.environ:
+            cls.postgres_conn = os.environ['QGIS_PGTEST_DB']
+        cls.uri = cls.postgres_conn + ' sslmode=disable'
+
+    def testModel(self):
+        conn = QgsProviderRegistry.instance().providerMetadata('postgres').createConnection(self.uri, {})
+        self.assertTrue(conn)
+        model = QgsDatabaseSchemaModel(conn)
+        self.assertGreaterEqual(model.rowCount(), 3)
+        old_count = model.rowCount()
+        self.assertEqual(model.columnCount(), 1)
+        schemas = [model.data(model.index(r, 0, QModelIndex()), Qt.DisplayRole) for r in range(model.rowCount())]
+        self.assertIn('public', schemas)
+        self.assertIn('CamelCaseSchema', schemas)
+        self.assertIn('qgis_test', schemas)
+        self.assertEqual(model.data(model.index(schemas.index('qgis_test'), 0, QModelIndex()), Qt.ToolTipRole), 'qgis_test')
+        self.assertIsNone(model.data(model.index(model.rowCount(), 0, QModelIndex()), Qt.DisplayRole))
+
+        model.refresh()
+        self.assertEqual(model.rowCount(), old_count)
+
+        conn.createSchema('myNewSchema')
+        self.assertEqual(model.rowCount(), old_count)
+        model.refresh()
+        self.assertEqual(model.rowCount(), old_count + 1)
+        schemas = [model.data(model.index(r, 0, QModelIndex()), Qt.DisplayRole) for r in range(model.rowCount())]
+        self.assertIn('public', schemas)
+        self.assertIn('CamelCaseSchema', schemas)
+        self.assertIn('qgis_test', schemas)
+        self.assertIn('myNewSchema', schemas)
+
+        conn.createSchema('myNewSchema2')
+        conn.createSchema('myNewSchema3')
+        model.refresh()
+        self.assertEqual(model.rowCount(), old_count + 3)
+        schemas = [model.data(model.index(r, 0, QModelIndex()), Qt.DisplayRole) for r in range(model.rowCount())]
+        self.assertIn('public', schemas)
+        self.assertIn('CamelCaseSchema', schemas)
+        self.assertIn('qgis_test', schemas)
+        self.assertIn('myNewSchema', schemas)
+        self.assertIn('myNewSchema2', schemas)
+        self.assertIn('myNewSchema3', schemas)
+
+        conn.createSchema('myNewSchema4')
+        conn.dropSchema('myNewSchema2')
+        conn.dropSchema('myNewSchema')
+        model.refresh()
+        self.assertEqual(model.rowCount(), old_count + 2)
+        schemas = [model.data(model.index(r, 0, QModelIndex()), Qt.DisplayRole) for r in range(model.rowCount())]
+        self.assertIn('public', schemas)
+        self.assertIn('CamelCaseSchema', schemas)
+        self.assertIn('qgis_test', schemas)
+        self.assertNotIn('myNewSchema', schemas)
+        self.assertNotIn('myNewSchema2', schemas)
+        self.assertIn('myNewSchema3', schemas)
+        self.assertIn('myNewSchema4', schemas)
+
+        conn.dropSchema('myNewSchema3')
+        conn.dropSchema('myNewSchema4')
+        model.refresh()
+        self.assertEqual(model.rowCount(), old_count)
+        schemas = [model.data(model.index(r, 0, QModelIndex()), Qt.DisplayRole) for r in range(model.rowCount())]
+        self.assertIn('public', schemas)
+        self.assertIn('CamelCaseSchema', schemas)
+        self.assertIn('qgis_test', schemas)
+        self.assertNotIn('myNewSchema3', schemas)
+        self.assertNotIn('myNewSchema4', schemas)
+
+
+if __name__ == '__main__':
+    unittest.main()