Add API to QgsProjectStorage to determine matching project storage

implementation from a file path
qgis · Jul 15, 2021 · 1f31a38 · 1f31a38
1 parent dc33847
commit 1f31a38
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diff --git a/python/core/auto_generated/project/qgsprojectstorage.sip.in b/python/core/auto_generated/project/qgsprojectstorage.sip.in
@@ -47,6 +47,19 @@ Metadata associated with a project
 %Docstring
 Unique identifier of the project storage type. If :py:func:`~QgsProjectStorage.type` returns "memory", all project file names
 starting with "memory:" will have read/write redirected through that storage implementation.
+%End
+
+    virtual bool isSupportedUri( const QString &uri ) const;
+%Docstring
+Returns ``True`` if the specified ``uri`` is supported by the storage provider.
+
+.. note::
+
+   This method does not actually test whether the ``uri`` contains projects, but
+   rather it is a quick test to determine if it is possible that the uri may
+   contain projects.
+
+.. versionadded:: 3.22
 %End
 
     virtual QStringList listProjects( const QString &uri ) = 0;

diff --git a/src/core/project/qgsprojectstorage.cpp b/src/core/project/qgsprojectstorage.cpp
@@ -15,6 +15,11 @@
 
 #include "qgsprojectstorage.h"
 
+bool QgsProjectStorage::isSupportedUri( const QString & ) const
+{
+  return false;
+}
+
 QString QgsProjectStorage::filePath( const QString &uri )
 {
   Q_UNUSED( uri );

diff --git a/src/core/project/qgsprojectstorage.h b/src/core/project/qgsprojectstorage.h
@@ -59,6 +59,17 @@ class CORE_EXPORT QgsProjectStorage
      */
     virtual QString type() = 0;
 
+    /**
+     * Returns TRUE if the specified \a uri is supported by the storage provider.
+     *
+     * \note This method does not actually test whether the \a uri contains projects, but
+     * rather it is a quick test to determine if it is possible that the uri may
+     * contain projects.
+     *
+     * \since QGIS 3.22
+     */
+    virtual bool isSupportedUri( const QString &uri ) const;
+
     //! Returns list of all projects for given URI (specific to each storage backend)
     virtual QStringList listProjects( const QString &uri ) = 0;
 

diff --git a/src/core/project/qgsprojectstorageregistry.cpp b/src/core/project/qgsprojectstorageregistry.cpp
@@ -37,6 +37,14 @@ QgsProjectStorage *QgsProjectStorageRegistry::projectStorageFromUri( const QStri
     if ( uri.startsWith( scheme ) )
       return storage;
   }
+
+  // second chance -- use isSupportedUri to determine if a uri is supported by a backend
+  for ( auto it = mBackends.constBegin(); it != mBackends.constEnd(); ++it )
+  {
+    QgsProjectStorage *storage = it.value();
+    if ( storage->isSupportedUri( uri ) )
+      return storage;
+  }
   return nullptr;
 }
 

diff --git a/src/core/providers/ogr/qgsgeopackageprojectstorage.cpp b/src/core/providers/ogr/qgsgeopackageprojectstorage.cpp
@@ -97,6 +97,12 @@ static bool _projectsTableExists( const QString &database )
   return ok;
 }
 
+bool QgsGeoPackageProjectStorage::isSupportedUri( const QString &uri ) const
+{
+  const QFileInfo fi( uri );
+  return fi.isFile() && fi.suffix().compare( QLatin1String( "gpkg" ), Qt::CaseInsensitive ) == 0;
+}
+
 QStringList QgsGeoPackageProjectStorage::listProjects( const QString &uri )
 {
   QStringList lst;

diff --git a/src/core/providers/ogr/qgsgeopackageprojectstorage.h b/src/core/providers/ogr/qgsgeopackageprojectstorage.h
@@ -41,6 +41,7 @@ class CORE_EXPORT QgsGeoPackageProjectStorage : public QgsProjectStorage
     // QgsProjectStorage interface
   public:
     QString type() override { return QStringLiteral( "geopackage" ); }
+    bool isSupportedUri( const QString &uri ) const override;
     QStringList listProjects( const QString &uri ) override;
     bool readProject( const QString &uri, QIODevice *device, QgsReadWriteContext &context ) override;
     bool writeProject( const QString &uri, QIODevice *device, QgsReadWriteContext &context ) override;

diff --git a/tests/src/core/testqgsprojectstorage.cpp b/tests/src/core/testqgsprojectstorage.cpp
@@ -34,6 +34,7 @@ class TestQgsProjectStorage : public QObject
     void cleanup();// will be called after every testfunction.
 
     void testMemoryStorage();
+    void testSupportedUri();
 };
 
 void TestQgsProjectStorage::init()
@@ -241,6 +242,17 @@ void TestQgsProjectStorage::testMemoryStorage()
   QgsApplication::projectStorageRegistry()->unregisterProjectStorage( memStorage );
 }
 
+void TestQgsProjectStorage::testSupportedUri()
+{
+  QgsProjectStorage *gpkgStorage = QgsApplication::projectStorageRegistry()->projectStorageFromType( QStringLiteral( "geopackage" ) );
+  QVERIFY( gpkgStorage );
+
+  QVERIFY( gpkgStorage->isSupportedUri( QStringLiteral( "%1/mixed_layers.gpkg" ).arg( TEST_DATA_DIR ) ) );
+  QVERIFY( !gpkgStorage->isSupportedUri( QStringLiteral( "%1/mixed_types.TAB" ).arg( TEST_DATA_DIR ) ) );
+
+  QCOMPARE( QgsApplication::projectStorageRegistry()->projectStorageFromUri( QStringLiteral( "%1/mixed_layers.gpkg" ).arg( TEST_DATA_DIR ) )->type(), QStringLiteral( "geopackage" ) );
+}
+
 
 QGSTEST_MAIN( TestQgsProjectStorage )
 #include "testqgsprojectstorage.moc"