Merge pull request #7012 from elpaso/python-provider

Python provider QEP 122

Author: elpaso

python/core/auto_generated/qgsfeatureiterator.sip.in

@@ -223,11 +223,15 @@ Wrapper for iterator of features from vector data provider or vector layer
 
     QgsFeatureIterator();
 %Docstring
-construct invalid iterator
+Construct invalid iterator
+%End
+    QgsFeatureIterator( QgsAbstractFeatureIterator *iter /Transfer/ );
+%Docstring
+Construct a valid iterator
 %End
     QgsFeatureIterator( const QgsFeatureIterator &fi );
 %Docstring
-copy constructor copies the iterator, increases ref.count
+Copy constructor copies the iterator, increases ref.count
 %End
     ~QgsFeatureIterator();
 

python/core/auto_generated/qgsprovidermetadata.sip.in

@@ -36,6 +36,51 @@ library object.
 
     QgsProviderMetadata( const QString &_key, const QString &_description, const QString &_library );
 
+    QgsProviderMetadata( const QString &key, const QString &description, SIP_PYCALLABLE / AllowNone / );
+%Docstring
+Metadata for provider with direct provider creation function pointer, where
+no library is involved.
+
+.. versionadded:: 3.0
+%End
+%MethodCode
+
+    // Make sure the callable doesn't get garbage collected, this is needed because refcount for a2 is 0
+    // and the creation function pointer is passed to the metadata and it needs to be kept in memory.
+    Py_INCREF( a2 );
+
+    Py_BEGIN_ALLOW_THREADS
+
+    sipCpp = new QgsProviderMetadata( *a0, *a1, [a2]( const QString &dataSource, const QgsDataProvider::ProviderOptions &providerOptions ) -> QgsDataProvider*
+    {
+      QgsDataProvider *provider;
+      provider = nullptr;
+      PyObject *sipResObj;
+      SIP_BLOCK_THREADS
+
+      sipResObj = sipCallMethod( nullptr, a2, "DD", new QString( dataSource ), sipType_QString, nullptr, new QgsDataProvider::ProviderOptions( providerOptions ), sipType_QgsDataProvider_ProviderOptions, NULL );
+
+      if ( sipResObj )
+      {
+        if ( sipCanConvertToType( sipResObj, sipType_QgsDataProvider, SIP_NOT_NONE ) )
+        {
+          int state0;
+          int sipIsErr = 0;
+          provider = reinterpret_cast<QgsDataProvider *>( sipConvertToType( sipResObj, sipType_QgsDataProvider, nullptr, SIP_NOT_NONE, &state0, &sipIsErr ) );
+          if ( sipIsErr != 0 )
+          {
+            sipReleaseType( provider, sipType_QgsDataProvider, state0 );
+            provider = nullptr;
+          }
+        }
+      }
+      SIP_UNBLOCK_THREADS
+      return provider;
+    } );
+
+    Py_END_ALLOW_THREADS
+
+%End
 
     QString key() const;
 %Docstring

python/core/auto_generated/qgsproviderregistry.sip.in

@@ -180,6 +180,19 @@ Returns a string containing the available protocol drivers
 
     void registerGuis( QWidget *widget );
 
+    bool registerProvider( QgsProviderMetadata *providerMetadata /Transfer/ );
+%Docstring
+register a new vector data provider from its ``providerMetadata``
+
+:return: true on success, false if a provider with the same key was already registered
+
+.. note::
+
+   ownership of the QgsProviderMetadata instance is transferred to the registry
+
+.. versionadded:: 3.2
+%End
+
 
 
   private:

src/core/qgsfeatureiterator.h

@@ -286,15 +286,13 @@ class CORE_EXPORT QgsFeatureIterator
     % End
 #endif
 
-    //! construct invalid iterator
+    //! Construct invalid iterator
     QgsFeatureIterator() = default;
-#ifndef SIP_RUN
-    //! construct a valid iterator
-    QgsFeatureIterator( QgsAbstractFeatureIterator *iter );
-#endif
-    //! copy constructor copies the iterator, increases ref.count
+    //! Construct a valid iterator
+    QgsFeatureIterator( QgsAbstractFeatureIterator *iter SIP_TRANSFER );
+    //! Copy constructor copies the iterator, increases ref.count
     QgsFeatureIterator( const QgsFeatureIterator &fi );
-    //! destructor deletes the iterator if it has no more references
+    //! Destructor deletes the iterator if it has no more references
     ~QgsFeatureIterator();
 
     QgsFeatureIterator &operator=( const QgsFeatureIterator &other );

src/core/qgsmaplayer.cpp

@@ -912,7 +912,7 @@ QString QgsMapLayer::loadNamedProperty( const QString &uri, QgsMapLayer::Propert
   QFile myFile( uri );
   if ( myFile.open( QFile::ReadOnly ) )
   {
-    QgsDebugMsg( QString( "file found %1" ).arg( uri ) );
+    QgsDebugMsgLevel( QString( "file found %1" ).arg( uri ), 2 );
     // read file
     resultFlag = myDocument.setContent( &myFile, &myErrorMessage, &line, &column );
     if ( !resultFlag )

src/core/qgsprovidermetadata.h

@@ -58,10 +58,51 @@ class CORE_EXPORT QgsProviderMetadata
     /**
      * Metadata for provider with direct provider creation function pointer, where
      * no library is involved.
-     * \note not available in Python bindings
      * \since QGIS 3.0
      */
-    SIP_SKIP QgsProviderMetadata( const QString &key, const QString &description, const QgsProviderMetadata::CreateDataProviderFunction &createFunc );
+#ifndef SIP_RUN
+    QgsProviderMetadata( const QString &key, const QString &description, const QgsProviderMetadata::CreateDataProviderFunction &createFunc );
+#else
+    QgsProviderMetadata( const QString &key, const QString &description, SIP_PYCALLABLE / AllowNone / );
+    % MethodCode
+
+    // Make sure the callable doesn't get garbage collected, this is needed because refcount for a2 is 0
+    // and the creation function pointer is passed to the metadata and it needs to be kept in memory.
+    Py_INCREF( a2 );
+
+    Py_BEGIN_ALLOW_THREADS
+
+    sipCpp = new QgsProviderMetadata( *a0, *a1, [a2]( const QString &dataSource, const QgsDataProvider::ProviderOptions &providerOptions ) -> QgsDataProvider*
+    {
+      QgsDataProvider *provider;
+      provider = nullptr;
+      PyObject *sipResObj;
+      SIP_BLOCK_THREADS
+
+      sipResObj = sipCallMethod( nullptr, a2, "DD", new QString( dataSource ), sipType_QString, nullptr, new QgsDataProvider::ProviderOptions( providerOptions ), sipType_QgsDataProvider_ProviderOptions, NULL );
+
+      if ( sipResObj )
+      {
+        if ( sipCanConvertToType( sipResObj, sipType_QgsDataProvider, SIP_NOT_NONE ) )
+        {
+          int state0;
+          int sipIsErr = 0;
+          provider = reinterpret_cast<QgsDataProvider *>( sipConvertToType( sipResObj, sipType_QgsDataProvider, nullptr, SIP_NOT_NONE, &state0, &sipIsErr ) );
+          if ( sipIsErr != 0 )
+          {
+            sipReleaseType( provider, sipType_QgsDataProvider, state0 );
+            provider = nullptr;
+          }
+        }
+      }
+      SIP_UNBLOCK_THREADS
+      return provider;
+    } );
+
+    Py_END_ALLOW_THREADS
+
+    % End
+#endif
 
     /**
      * This returns the unique key associated with the provider

src/core/qgsproviderregistry.cpp

@@ -525,6 +525,27 @@ void QgsProviderRegistry::registerGuis( QWidget *parent )
   }
 }
 
+bool QgsProviderRegistry::registerProvider( QgsProviderMetadata *providerMetadata )
+{
+  if ( providerMetadata )
+  {
+    if ( mProviders.find( providerMetadata->key() ) == mProviders.end() )
+    {
+      mProviders[ providerMetadata->key() ] = providerMetadata;
+      return true;
+    }
+    else
+    {
+      QgsDebugMsgLevel( QStringLiteral( "Cannot register provider metadata: a provider with the same key (%1) was already registered!" ).arg( providerMetadata->key() ), 2 );
+    }
+  }
+  else
+  {
+    QgsDebugMsgLevel( QStringLiteral( "Trying to register a null metadata provider!" ), 2 );
+  }
+  return false;
+}
+
 QString QgsProviderRegistry::fileVectorFilters() const
 {
   return mVectorFileFilters;

src/core/qgsproviderregistry.h

@@ -179,6 +179,14 @@ class CORE_EXPORT QgsProviderRegistry
 
     void registerGuis( QWidget *widget );
 
+    /**
+     * \brief register a new vector data provider from its \a providerMetadata
+     * \return true on success, false if a provider with the same key was already registered
+     * \note ownership of the QgsProviderMetadata instance is transferred to the registry
+     * \since QGIS 3.2
+     */
+    bool registerProvider( QgsProviderMetadata *providerMetadata SIP_TRANSFER );
+
     /**
      * Open the given vector data source
      *

src/core/qgsvectordataprovider.cpp

@@ -408,6 +408,12 @@ QVariant QgsVectorDataProvider::maximumValue( int index ) const
 
 QStringList QgsVectorDataProvider::uniqueStringsMatching( int index, const QString &substring, int limit, QgsFeedback *feedback ) const
 {
+  QStringList results;
+
+  // Safety belt
+  if ( index < 0 || index >= fields().count() )
+    return results;
+
   QgsFeature f;
   QgsAttributeList keys;
   keys.append( index );
@@ -420,7 +426,6 @@ QStringList QgsVectorDataProvider::uniqueStringsMatching( int index, const QStri
   QgsFeatureIterator fi = getFeatures( request );
 
   QSet<QString> set;
-  QStringList results;
 
   while ( fi.nextFeature( f ) )
   {

tests/src/python/CMakeLists.txt

@@ -11,6 +11,7 @@ ENDIF (WITH_SERVER)
 ADD_PYTHON_TEST(PyCoreAdittions test_core_additions.py)
 ADD_PYTHON_TEST(PyQgsActionManager test_qgsactionmanager.py)
 ADD_PYTHON_TEST(PyQgsAFSProvider test_provider_afs.py)
+ADD_PYTHON_TEST(PyQgsPythonProvider test_provider_python.py)
 ADD_PYTHON_TEST(PyQgsAggregateCalculator test_qgsaggregatecalculator.py)
 ADD_PYTHON_TEST(PyQgsAnnotation test_qgsannotation.py)
 ADD_PYTHON_TEST(PyQgsApplication test_qgsapplication.py)