QgsVirtualLayerDefinition QgsVirtualLayerDefinitionUtils::fromJoinedLayer( QgsVectorLayer *layer )
{
QgsVirtualLayerDefinition def;
QStringList leftJoins;
QStringList columns;
// add the geometry column if the layer is spatial
if ( layer->isSpatial() )
columns << "t.geometry";
// look for the uid
QgsFields fields = layer->dataProvider()->fields();
{
QgsAttributeList pk = layer->dataProvider()->pkAttributeIndexes();
if ( pk.size() == 1 )
{
def.setUid( fields.field( pk[0] ).name() );
}
else
{
// find an uid name
QString uid = QStringLiteral( "uid" );
while ( fields.lookupField( uid ) != -1 )
uid += QLatin1String( "_" ); // add "_" each time this name already exists
// add a column
columns << "t.rowid AS " + uid;
def.setUid( uid );
}
}
const QgsFields providerFields = layer->dataProvider()->fields();
for ( const auto &f : providerFields )
{
columns << "t.\"" + f.name() + "\"";
}
int joinIdx = 0;
Q_FOREACH ( const QgsVectorLayerJoinInfo &join, layer->vectorJoins() )
{
QString joinName = QStringLiteral( "j%1" ).arg( ++joinIdx );
QgsVectorLayer *joinedLayer = join.joinLayer();
if ( !joinedLayer )
continue;
QString prefix = join.prefix().isEmpty() ? joinedLayer->name() + "_" : join.prefix();
leftJoins << QStringLiteral( "LEFT JOIN \"%1\" AS %2 ON t.\"%5\"=%2.\"%3\"" ).arg( joinedLayer->id(), joinName, join.joinFieldName(), join.targetFieldName() );
if ( join.joinFieldNamesSubset() )
{
Q_FOREACH ( const QString &f, *join.joinFieldNamesSubset() )
{
columns << joinName + ".\"" + f + "\" AS \"" + prefix + f + "\"";
}
}
else
{
QGISEXTERN QgsVirtualLayerSourceSelect *createWidget( QWidget *parent, Qt::WindowFlags fl, const QList<QPair<QString, QString> >& parameters )
{
QgsVirtualLayerSourceSelect *w = new QgsVirtualLayerSourceSelect( parent, fl );
QString name, source, encoding;
foreach ( const auto& p, parameters ) {
if ((p.first == "fromUrl") || (p.first == "fromFile")) {
QgsVirtualLayerDefinition def;
if (p.first == "fromUrl") {
QUrl url( QUrl::fromEncoded( p.second.toLocal8Bit() ) );
def.fromUrl( url );
}
else {
def = virtualLayerDefinitionFromSqlite( p.second );
}
w->setQuery( def.query() );
w->setUid( def.uid() );
w->setGeometryColumn( def.geometryField() );
foreach ( const auto& l, def.sourceLayers() ) {
w->addSource( l.name(), l.source(), l.provider(), l.encoding() );
}
w->setFilename( def.uri() );
break;
}
else if (p.first == "layer") {
QgsVirtualLayerDefinition QgsVirtualLayerDefinition::fromUrl( const QUrl& url )
{
QgsVirtualLayerDefinition def;
def.setFilePath( url.path() );
// regexp for column name
const QString columnNameRx( "[a-zA-Z_\x80-\xFF][a-zA-Z0-9_\x80-\xFF]*" );
QgsFields fields;
int layerIdx = 0;
QList<QPair<QString, QString> > items = url.queryItems();
for ( int i = 0; i < items.size(); i++ )
{
QString key = items.at( i ).first;
QString value = items.at( i ).second;
if ( key == "layer_ref" )
{
layerIdx++;
// layer id, with optional layer_name
int pos = value.indexOf( ':' );
QString layerId, vlayerName;
if ( pos == -1 )
{
layerId = value;
vlayerName = QString( "vtab%1" ).arg( layerIdx );
}
else
{
layerId = value.left( pos );
vlayerName = QUrl::fromPercentEncoding( value.mid( pos + 1 ).toUtf8() );
}
// add the layer to the list
def.addSource( vlayerName, layerId );
}
else if ( key == "layer" )
{
layerIdx++;
// syntax: layer=provider:url_encoded_source_URI(:name(:encoding)?)?
int pos = value.indexOf( ':' );
if ( pos != -1 )
{
QString providerKey, source, vlayerName, encoding = "UTF-8";
providerKey = value.left( pos );
int pos2 = value.indexOf( ':', pos + 1 );
if ( pos2 != -1 )
{
source = QUrl::fromPercentEncoding( value.mid( pos + 1, pos2 - pos - 1 ).toUtf8() );
int pos3 = value.indexOf( ':', pos2 + 1 );
if ( pos3 != -1 )
{
vlayerName = QUrl::fromPercentEncoding( value.mid( pos2 + 1, pos3 - pos2 - 1 ).toUtf8() );
encoding = value.mid( pos3 + 1 );
}
else
{
vlayerName = QUrl::fromPercentEncoding( value.mid( pos2 + 1 ).toUtf8() );
}
}
else
{
source = QUrl::fromPercentEncoding( value.mid( pos + 1 ).toUtf8() );
vlayerName = QString( "vtab%1" ).arg( layerIdx );
}
def.addSource( vlayerName, source, providerKey, encoding );
}
}
else if ( key == "geometry" )
{
// geometry field definition, optional
// geometry_column(:wkb_type:srid)?
QRegExp reGeom( "(" + columnNameRx + ")(?::([a-zA-Z0-9]+):(\\d+))?" );
int pos = reGeom.indexIn( value );
if ( pos >= 0 )
{
def.setGeometryField( reGeom.cap( 1 ) );
if ( reGeom.captureCount() > 1 )
{
// not used by the spatialite provider for now ...
QgsWKBTypes::Type wkbType = QgsWKBTypes::parseType( reGeom.cap( 2 ) );
if ( wkbType == QgsWKBTypes::Unknown )
{
wkbType = static_cast<QgsWKBTypes::Type>( reGeom.cap( 2 ).toLong() );
}
def.setGeometryWkbType( wkbType );
def.setGeometrySrid( reGeom.cap( 3 ).toLong() );
}
}
}
else if ( key == "nogeometry" )
{
def.setGeometryWkbType( QgsWKBTypes::NoGeometry );
}
else if ( key == "uid" )
{
def.setUid( value );
}
else if ( key == "query" )
{
// url encoded query
def.setQuery( value );
}
else if ( key == "field" )
{
// field_name:type (int, real, text)
QRegExp reField( "(" + columnNameRx + "):(int|real|text)" );
int pos = reField.indexIn( value );
if ( pos >= 0 )
{
QString fieldName( reField.cap( 1 ) );
QString fieldType( reField.cap( 2 ) );
if ( fieldType == "int" )
{
fields.append( QgsField( fieldName, QVariant::Int, fieldType ) );
}
else if ( fieldType == "real" )
{
fields.append( QgsField( fieldName, QVariant::Double, fieldType ) );
}
if ( fieldType == "text" )
{
fields.append( QgsField( fieldName, QVariant::String, fieldType ) );
}
}
}
}
def.setFields( fields );
return def;
}
