Moved python provider to separate file

Also cloned other memory layer methods

tests/src/python/provider_python.py

@@ -0,0 +1,297 @@
+# -*- coding: utf-8 -*-
+"""QGIS test python layer provider.
+
+.. 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__ = 'Alessandro Pasotti'
+__date__ = '2018-03-18'
+__copyright__ = 'Copyright 2018, The QGIS Project'
+# This will get replaced with a git SHA1 when you do a git archive
+__revision__ = '$Format:%H$'
+
+
+from qgis.core import (
+    QgsField,
+    QgsFields,
+    QgsLayerDefinition,
+    QgsPointXY,
+    QgsReadWriteContext,
+    QgsVectorLayer,
+    QgsFeatureRequest,
+    QgsFeature,
+    QgsGeometry,
+    QgsWkbTypes,
+    NULL,
+    QgsMemoryProviderUtils,
+    QgsCoordinateReferenceSystem,
+    QgsRectangle,
+    QgsTestUtils,
+    QgsVectorDataProvider,
+    QgsAbstractFeatureSource,
+    QgsAbstractFeatureIterator,
+    QgsFeatureIterator,
+    QgsApplication,
+    QgsProviderRegistry,
+    QgsProviderMetadata,
+)
+
+from qgis.PyQt.QtCore import QVariant
+
+
+class PyFeatureIterator(QgsFeatureIterator):
+
+    def __init__(self, source, request):
+        super(PyFeatureIterator, self).__init__()
+        self._request = request
+        self._index = 0
+        self._source = source
+
+    def nextFeature(self, f):
+        """fetch next feature, return true on success"""
+        #virtual bool nextFeature( QgsFeature &f );
+        try:
+            _f = self._source._features[self._index]
+            self._index += 1
+            f.setAttributes(_f.attributes())
+            f.setGeometry(_f.geometry())
+            f.setValid(_f.isValid())
+            return True
+        except Exception as e:
+            f.setValid(False)
+            return False
+
+    def __iter__(self):
+        'Returns itself as an iterator object'
+        return self
+
+    def __next__(self):
+        'Returns the next value till current is lower than high'
+        f = QgsFeature()
+        if not self.nextFeature(f):
+            raise StopIteration
+        else:
+            return f
+
+    def rewind(self):
+        """reset the iterator to the starting position"""
+        #virtual bool rewind() = 0;
+        self._index = 0
+
+    def close(self):
+        """end of iterating: free the resources / lock"""
+        #virtual bool close() = 0;
+        self._index = 0
+        return True
+
+
+class PyFeatureSource(QgsAbstractFeatureSource):
+
+    def __init__(self, provider):
+        super(PyFeatureSource, self).__init__()
+        self._provider = provider
+        self._features = provider._features
+
+    def getFeatures(self, request):
+        # QgsFeatureIterator getFeatures( const QgsFeatureRequest &request ) override;
+        # NOTE: this is the same as PyProvider.getFeatures
+        return PyFeatureIterator(self, request)
+
+class PyProvider(QgsVectorDataProvider):
+
+    next_feature_id = 1
+
+    @classmethod
+    def providerKey(cls):
+        """Returns the memory provider key"""
+        #static QString providerKey();
+        return 'pythonprovider'
+
+    @classmethod
+    def description(cls):
+        """Returns the memory provider description"""
+        #static QString providerDescription();
+        return 'Python Test Provider'
+
+    @classmethod
+    def createProvider(cls, uri):
+        #static QgsMemoryProvider *createProvider( const QString &uri );
+        return PyProvider(uri)
+
+    # Implementation of functions from QgsVectorDataProvider
+
+    def __init__(self, uri=''):
+        super(PyProvider, self).__init__(uri)
+        # Use the memory layer to parse the uri
+        mlayer = QgsVectorLayer(uri, 'ml', 'memory')
+        self._uri = uri
+        self._fields = mlayer.fields()
+        self._wkbType = mlayer.wkbType()
+        self._features = {}
+        self._extent = QgsRectangle()
+        self._extent.setMinimal()
+        self._subset_string = ''
+
+    def featureSource(self):
+        return PyFeatureSource(self)
+
+    def dataSourceUri(self, expandAuthConfig=True):
+        #QString dataSourceUri( bool expandAuthConfig = true ) const override;
+        return self._uri
+
+    def storageType(self):
+        #QString storageType() const override;
+        return "Python test memory storage"
+
+    def getFeatures(self, request=None):
+        #QgsFeatureIterator getFeatures( const QgsFeatureRequest &request ) const override;
+        return PyFeatureIterator(PyFeatureSource(self), request)
+
+    def wkbType(self):
+        #QgsWkbTypes::Type wkbType() const override;
+        return self._wkbType
+
+    def featureCount(self):
+        # TODO: get from source
+        # long featureCount() const override;
+        return len(self._features)
+
+    def fields(self):
+        #QgsFields fields() const override;
+        return self._fields
+
+    def addFeatures(self, flist, flags=None):
+        # bool addFeatures( QgsFeatureList &flist, QgsFeatureSink::Flags flags = nullptr ) override;
+        result = False
+        for f in flist:
+            f.setId(self.next_feature_id)
+            self._features[self.next_feature_id] = f
+            self.next_feature_id += 1
+            result = True
+        return result
+
+    def deleteFeatures(self, ids):
+        #bool deleteFeatures( const QgsFeatureIds &id ) override;
+        removed = False
+        for id in ids:
+            if id in self._features:
+                del self._features[id]
+                removed = True
+        return removed
+
+    def addAttributes(self, attrs):
+        #bool addAttributes( const QList<QgsField> &attributes ) override;
+        try:
+            self._fields.append(attrs)
+            for new_f in attrs:
+                for f in self._features.values():
+                    old_attrs = f.attributes()
+                    old_attrs.app
+                    old_attrs.append( None )
+                    f.setAttributes( old_attrs )
+            return True
+        except:
+            return False
+
+    def renameAttributes(self, renameAttributes):
+        #bool renameAttributes( const QgsFieldNameMap &renamedAttributes ) override;
+        result = True
+        for key, new_name in renamedAttributes:
+            fieldIndex = key
+            if  fieldIndex < 0 or fieldIndex >= lself._fields.count():
+                result = false
+                continue
+            if new_name in self._fields.indexFromName( new_name ) >= 0:
+                #field name already in use
+                result = False
+                continue
+            self._fields[ fieldIndex ].setName( new_name );
+        return True
+
+    def deleteAttributes(self, attributes):
+        #bool deleteAttributes( const QgsAttributeIds &attributes ) override;
+        attrIdx = sorted(attributes.toList(), reverse=True)
+
+        # delete attributes one-by-one with decreasing index
+        for idx in attrIdx:
+            self._fields.remove( idx )
+            for f in self._features:
+                attr = f.attributes()
+                attr.remove( idx )
+                f.setAttributes( attr )
+        return True
+
+    def changeAttributeValues(self, attr_map):
+        #bool changeAttributeValues( const QgsChangedAttributesMap &attr_map ) override;
+        for feature_id, attrs in attr_map.items():
+            try:
+                f = self._features[feature_id]
+            except KeyError:
+                continue
+            for k, v in attrs:
+                f.setAttribute(k, v)
+        return True
+
+    def changeGeometryValues(self, geometry_map):
+        #bool changeGeometryValues( const QgsGeometryMap &geometry_map ) override;
+        #TODO
+        return True
+
+    def subsetString(self):
+        #QString subsetString() const override;
+        return self._subset_string
+
+    def setSubsetString(self, subsetString):
+        #bool setSubsetString( const QString &theSQL, bool updateFeatureCount = true ) override;
+        self._subset_string = subsetString
+
+    def supportsSubsetString(self):
+        #bool supportsSubsetString() const override { return true; }
+        return True
+
+    def createSpatialIndex(self):
+        #bool createSpatialIndex() override;
+        return True
+
+    def capabilities(self):
+        #QgsVectorDataProvider::Capabilities capabilities() const override;
+        return QgsVectorDataProvider.AddFeatures | QgsVectorDataProvider.DeleteFeatures | QgsVectorDataProvider.ChangeGeometries | QgsVectorDataProvider.ChangeAttributeValues | QgsVectorDataProvider.AddAttributes | QgsVectorDataProvider.DeleteAttributes | QgsVectorDataProvider.RenameAttributes | QgsVectorDataProvider.CreateSpatialIndex | QgsVectorDataProvider.SelectAtId | QgsVectorDataProvider. CircularGeometries
+
+    #/* Implementation of functions from QgsDataProvider */
+
+    def name(self):
+        #QString name() const override;
+        return self.providerKey()
+
+    def extent(self):
+        #QgsRectangle extent() const override;
+        if self._extent.isEmpty() and not self._features.isEmpty():
+            self._extent.setMinimal()
+            if self._subset_string.isEmpty():
+                # fast way - iterate through all features
+                for feat in self._features.values():
+                    if feat.hasGeometry():
+                        self._extent.combineExtentWith( feat.geometry().boundingBox() )
+            else:
+                for f in self.getFeatures( QgsFeatureRequest().setSubsetOfAttributes( [] ) ):
+                    if f.hasGeometry():
+                        self._extent.combineExtentWith( f.geometry().boundingBox() )
+
+        elif self._features.isEmpty() :
+           self._extent.setMinimal();
+        return mExtent;       
+
+    def updateExtents(self):
+        #void updateExtents() override;
+        self._extent.setMinimal()
+
+    def isValid(self):
+        #bool isValid() const override;
+        return True
+
+    def crs(self):
+        #QgsCoordinateReferenceSystem crs() const override;
+        return QgsCoordinateReferenceSystem(4326)
+