QgsFeatureIterator QgsMssqlProvider::getFeatures( const QgsFeatureRequest& request )
{
if ( !mValid )
{
QgsDebugMsg( "Read attempt on an invalid mssql data source" );
return QgsFeatureIterator();
}
return QgsFeatureIterator( new QgsMssqlFeatureIterator( this, request ) );
}
QgsFeatureIterator QgsDb2Provider::getFeatures( const QgsFeatureRequest& request ) const
{
if ( !mValid )
{
QgsDebugMsg( "Read attempt on an invalid db2 data source" );
return QgsFeatureIterator();
}
return QgsFeatureIterator( new QgsDb2FeatureIterator( new QgsDb2FeatureSource( this ), true, request ) );
}
QgsFeatureIterator QgsDelimitedTextProvider::getFeatures( const QgsFeatureRequest& request )
{
// If the file has become invalid, rescan to check that it is still invalid.
//
if (( mLayerValid && ! mValid ) || mRescanRequired ) rescanFile();
return QgsFeatureIterator( new QgsDelimitedTextFeatureIterator( new QgsDelimitedTextFeatureSource( this ), true, request ) );
}
long QgsMemoryProvider::featureCount() const
{
if ( mSubsetString.isEmpty() )
return mFeatures.count();
// subset string set, no alternative but testing each feature
QgsFeatureIterator fit = QgsFeatureIterator( new QgsMemoryFeatureIterator( new QgsMemoryFeatureSource( this ), true, QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() ) ) );
int count = 0;
QgsFeature feature;
while ( fit.nextFeature( feature ) )
{
count++;
}
return count;
}
bool QgsCacheIndexFeatureId::getCacheIterator( QgsFeatureIterator &featureIterator, const QgsFeatureRequest &featureRequest )
{
switch ( featureRequest.filterType() )
{
case QgsFeatureRequest::FilterFid:
{
if ( C->isFidCached( featureRequest.filterFid() ) )
{
featureIterator = QgsFeatureIterator( new QgsCachedFeatureIterator( C, featureRequest ) );
return true;
}
break;
}
case QgsFeatureRequest::FilterFids:
{
if ( C->cachedFeatureIds().contains( featureRequest.filterFids() ) )
{
featureIterator = QgsFeatureIterator( new QgsCachedFeatureIterator( C, featureRequest ) );
return true;
}
break;
}
case QgsFeatureRequest::FilterNone:
case QgsFeatureRequest::FilterExpression:
{
if ( C->hasFullCache() )
{
featureIterator = QgsFeatureIterator( new QgsCachedFeatureIterator( C, featureRequest ) );
return true;
}
break;
}
}
return false;
}
QgsFeatureIterator QgsVectorLayerUtils::getValuesIterator( const QgsVectorLayer *layer, const QString &fieldOrExpression, bool &ok, bool selectedOnly )
{
std::unique_ptr<QgsExpression> expression;
QgsExpressionContext context;
int attrNum = layer->fields().lookupField( fieldOrExpression );
if ( attrNum == -1 )
{
// try to use expression
expression.reset( new QgsExpression( fieldOrExpression ) );
context.appendScopes( QgsExpressionContextUtils::globalProjectLayerScopes( layer ) );
if ( expression->hasParserError() || !expression->prepare( &context ) )
{
ok = false;
return QgsFeatureIterator();
}
}
QSet<QString> lst;
if ( !expression )
lst.insert( fieldOrExpression );
else
lst = expression->referencedColumns();
QgsFeatureRequest request = QgsFeatureRequest()
.setFlags( ( expression && expression->needsGeometry() ) ?
QgsFeatureRequest::NoFlags :
QgsFeatureRequest::NoGeometry )
.setSubsetOfAttributes( lst, layer->fields() );
ok = true;
if ( !selectedOnly )
{
return layer->getFeatures( request );
}
else
{
return layer->getSelectedFeatures( request );
}
}
QgsFeatureIterator QgsOgrFeatureSource::getFeatures( const QgsFeatureRequest& request )
{
return QgsFeatureIterator( new QgsOgrFeatureIterator( this, false, request ) );
}
QgsFeatureIterator QgsWFSProvider::getFeatures( const QgsFeatureRequest& request )
{
return QgsFeatureIterator( new QgsWFSFeatureIterator( new QgsWFSFeatureSource( this ), true, request ) );
}
QgsFeatureIterator QgsVectorLayerFeatureSource::getFeatures( const QgsFeatureRequest& request )
{
// return feature iterator that does not own this source
return QgsFeatureIterator( new QgsVectorLayerFeatureIterator( this, false, request ) );
}
QgsFeatureIterator QgsWFSFeatureSource::getFeatures( const QgsFeatureRequest& request )
{
if ( !request.filterRect().isNull() )
emit extentRequested( request.filterRect() );
return QgsFeatureIterator( new QgsWFSFeatureIterator( this, false, request ) );
}
QgsFeatureIterator QgsGPXProvider::getFeatures( const QgsFeatureRequest& request )
{
return QgsFeatureIterator( new QgsGPXFeatureIterator( this, request ) );
}
QgsFeatureIterator QgsMemoryProvider::getFeatures( const QgsFeatureRequest& request ) const
{
return QgsFeatureIterator( new QgsMemoryFeatureIterator( new QgsMemoryFeatureSource( this ), true, request ) );
}
