Merge pull request #4509 from nyalldawson/exporter

API Cleanups (and rename) for QgsVectorLayerImport, background export of layers when dropping to browser

doc/api_break.dox

@@ -186,6 +186,7 @@ Renamed Classes        {#qgis_api_break_3_0_renamed_classes}
 <tr><td>QgsVectorGradientColorRampV2DialogBase<td>QgsGradientColorRampDialogBase
 <tr><td>QgsVectorGradientRampV2<td>QgsVectorGradientRamp
 <tr><td>QgsVectorJoinInfo<td>QgsVectorLayerJoinInfo
+<tr><td>QgsVectorLayerImport<td>QgsVectorLayerExporter
 <tr><td>QgsVectorLayersetRendererV2<td>QgsVectorLayersetRenderer
 <tr><td>QgsVectorRandomColorRampV2<td>QgsLimitedRandomColorRamp
 <tr><td>QgsVectorRandomColorRampV2Dialog<td>QgsLimitedRandomColorRampDialog
@@ -2180,15 +2181,21 @@ QgsVectorLayerEditUtils        {#qgis_api_break_3_0_QgsVectorLayerEditUtils}
 - cache() has been removed.
 
 
-QgsVectorLayerImport        {#qgis_api_break_3_0_QgsVectorLayerImport}
+QgsVectorLayerExporter (renamed from QgsVectorLayerImport) {#qgis_api_break_3_0_QgsVectorLayerExporter}
 --------------------
 
-- QgsVectorLayerImport now takes references instead of pointers to QgsCoordinateReferenceSystem objects. Since
+- QgsVectorLayerExporter now takes references instead of pointers to QgsCoordinateReferenceSystem objects. Since
 QgsCoordinateReferenceSystem is now implicitly shared, using references to QgsCoordinateReferenceSystem rather than
 pointers makes for more robust, safer code. Use an invalid (default constructed) QgsCoordinateReferenceSystem
 in code which previously passed a null pointer to QgsVectorLayerImport.
-- The unused QProgressBar argument in the QgsVectorLayerImport was removed
-- ErrUserCancelled (ImportError enum value) has been renamed to ErrUserCanceled  <!--#spellok-->
+- importLayer was renamed to exportLayer
+- The unused skipAttributeCreation in exportLayer() was removed
+- The QProgressDialog argument in exportLayer() was changed to a QgsFeedback object.
+- The unused QProgressDialog argument in the QgsVectorLayerImport was removed
+- ImportError was renamed to ExportError
+- The unused enum value ErrDriverNotFound was removed
+- hasError() was renamed to errorCode()
+- ErrUserCancelled (ExportError enum value) has been renamed to ErrUserCanceled  <!--#spellok-->
 
 
 QgsVectorLayerJoinBuffer        {#qgis_api_break_3_0_QgsVectorLayerJoinBuffer}

python/core/core.sip

@@ -165,8 +165,8 @@
 %Include qgsvectorlayercache.sip
 %Include qgsvectorlayereditbuffer.sip
 %Include qgsvectorlayereditpassthrough.sip
+%Include qgsvectorlayerexporter.sip
 %Include qgsvectorlayerfeaturecounter.sip
-%Include qgsvectorlayerimport.sip
 %Include qgsvectorlayerjoinbuffer.sip
 %Include qgsvectorlayerjoininfo.sip
 %Include qgsvectorlayertools.sip

python/core/qgsvectorlayerexporter.sip

@@ -0,0 +1,200 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsvectorlayerexporter.h                                    *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+class QgsVectorLayerExporter : QgsFeatureSink
+{
+%Docstring
+ A convenience class for exporting vector layers to a destination data provider.
+
+ QgsVectorLayerExporter can be used in two ways:
+
+ 1. Using a static call to QgsVectorLayerExporter.exportLayer(...) which exports the
+ entire layer to the destination provider.
+
+ 2. Create an instance of the class and issue calls to addFeature(...)
+
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerexporter.h"
+%End
+  public:
+
+    enum ExportError
+    {
+      NoError,
+      ErrCreateDataSource,
+      ErrCreateLayer,
+      ErrAttributeTypeUnsupported,
+      ErrAttributeCreationFailed,
+      ErrProjection,
+      ErrFeatureWriteFailed,
+      ErrInvalidLayer,
+      ErrInvalidProvider,
+      ErrProviderUnsupportedFeature,
+      ErrConnectionFailed,
+      ErrUserCanceled,
+    };
+
+    static ExportError exportLayer( QgsVectorLayer *layer,
+                                    const QString &uri,
+                                    const QString &providerKey,
+                                    const QgsCoordinateReferenceSystem &destCRS,
+                                    bool onlySelected = false,
+                                    QString *errorMessage /Out/ = 0,
+                                    QMap<QString, QVariant> *options = 0,
+                                    QgsFeedback *feedback = 0
+                                  );
+%Docstring
+ Writes the contents of vector layer to a different datasource.
+ \param layer source layer
+ \param uri URI for destination data source
+ \param providerKey string key for destination data provider
+ \param destCRS destination CRS, or an invalid (default constructed) CRS if
+ not available
+ \param onlySelected set to true to export only selected features
+ \param errorMessage if non-null, will be set to any error messages
+ \param options optional provider dataset options
+ \param feedback optional feedback object to show progress and cancelation of export
+ :return: NoError for a successful export, or encountered error
+ :rtype: ExportError
+%End
+
+    QgsVectorLayerExporter( const QString &uri,
+                            const QString &provider,
+                            const QgsFields &fields,
+                            QgsWkbTypes::Type geometryType,
+                            const QgsCoordinateReferenceSystem &crs,
+                            bool overwrite = false,
+                            const QMap<QString, QVariant> *options = 0 );
+%Docstring
+ Constructor for QgsVectorLayerExporter.
+ \param uri URI for destination data source
+ \param provider string key for destination data provider
+ \param fields fields to include in created layer
+ \param geometryType destination geometry type
+ \param crs desired CRS, or an invalid (default constructed) CRS if
+ not available
+ \param overwrite set to true to overwrite any existing data source
+ \param options optional provider dataset options
+%End
+
+
+    ExportError errorCode() const;
+%Docstring
+ Returns any encountered error code, or false if no error was encountered.
+.. seealso:: errorMessage()
+.. seealso:: errorCount()
+ :rtype: ExportError
+%End
+
+    QString errorMessage() const;
+%Docstring
+ Returns any error message encountered during the export.
+.. seealso:: errorCount()
+.. seealso:: errorCode()
+ :rtype: str
+%End
+
+    int errorCount() const;
+%Docstring
+ Returns the number of error messages encountered during the export.
+.. seealso:: errorMessage()
+.. seealso:: errorCode()
+ :rtype: int
+%End
+
+    virtual bool addFeatures( QgsFeatureList &features );
+
+    virtual bool addFeature( QgsFeature &feature );
+
+
+    ~QgsVectorLayerExporter();
+%Docstring
+ Finalizes the export and closes the new created layer.
+%End
+
+  private:
+    QgsVectorLayerExporter( const QgsVectorLayerExporter &rh );
+};
+
+
+class QgsVectorLayerExporterTask : QgsTask
+{
+%Docstring
+ QgsTask task which performs a QgsVectorLayerExporter layer export operation as a background
+ task. This can be used to export a vector layer out to a provider without blocking the
+ QGIS interface.
+.. versionadded:: 3.0
+.. seealso:: QgsVectorFileWriterTask
+.. seealso:: QgsRasterFileWriterTask
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerexporter.h"
+%End
+  public:
+
+    QgsVectorLayerExporterTask( QgsVectorLayer *layer,
+                                const QString &uri,
+                                const QString &providerKey,
+                                const QgsCoordinateReferenceSystem &destinationCrs,
+                                QMap<QString, QVariant> *options = 0 );
+%Docstring
+ Constructor for QgsVectorLayerExporterTask. Takes a source ``layer``, destination ``uri``
+ and ``providerKey``, and various export related parameters such as destination CRS
+ and export ``options``.
+%End
+
+    static QgsVectorLayerExporterTask *withLayerOwnership( QgsVectorLayer *layer /Transfer/,
+        const QString &uri,
+        const QString &providerKey,
+        const QgsCoordinateReferenceSystem &destinationCrs,
+        QMap<QString, QVariant> *options = 0 ) /Factory/;
+%Docstring
+ Creates a new QgsVectorLayerExporterTask which has ownership over a source ``layer``.
+ When the export task has completed (successfully or otherwise) ``layer`` will be
+ deleted. The destination ``uri`` and ``providerKey``, and various export related parameters such as destination CRS
+ and export ``options`` must be specified.
+ :rtype: QgsVectorLayerExporterTask
+%End
+
+    virtual void cancel();
+
+  signals:
+
+    void exportComplete();
+%Docstring
+ Emitted when exporting the layer is successfully completed.
+%End
+
+    void errorOccurred( int error, const QString &errorMessage );
+%Docstring
+ Emitted when an error occurs which prevented the layer being exported (or if
+ the task is canceled). The export ``error`` and ``errorMessage`` will be reported.
+%End
+
+  protected:
+
+    virtual bool run();
+    virtual void finished( bool result );
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsvectorlayerexporter.h                                    *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

python/core/raster/qgsrasterfilewritertask.sip

@@ -16,6 +16,7 @@ class QgsRasterFileWriterTask : QgsTask
  task. This can be used to save a raster layer out to a file without blocking the
  QGIS interface.
 .. seealso:: QgsVectorFileWriterTask
+.. seealso:: QgsVectorFileExporterTask
 .. versionadded:: 3.0
 %End
 

python/plugins/db_manager/db_model.py

@@ -36,7 +36,7 @@
 from . import resources_rc  # NOQA
 
 try:
-    from qgis.core import QgsVectorLayerImport  # NOQA
+    from qgis.core import QgsVectorLayerExporter  # NOQA
     isImportVectorAvail = True
 except:
     isImportVectorAvail = False