QgsFeatureRenderer* QgsFeatureRenderer::loadSld( const QDomNode &node, QgsWkbTypes::GeometryType geomType, QString &errorMessage )
{
QDomElement element = node.toElement();
if ( element.isNull() )
return nullptr;
// get the UserStyle element
QDomElement userStyleElem = element.firstChildElement( "UserStyle" );
if ( userStyleElem.isNull() )
{
// UserStyle element not found, nothing will be rendered
errorMessage = "Info: UserStyle element not found.";
return nullptr;
}
// get the FeatureTypeStyle element
QDomElement featTypeStyleElem = userStyleElem.firstChildElement( "FeatureTypeStyle" );
if ( featTypeStyleElem.isNull() )
{
errorMessage = "Info: FeatureTypeStyle element not found.";
return nullptr;
}
// use the RuleRenderer when more rules are present or the rule
// has filters or min/max scale denominators set,
// otherwise use the SingleSymbol renderer
bool needRuleRenderer = false;
int ruleCount = 0;
QDomElement ruleElem = featTypeStyleElem.firstChildElement( "Rule" );
while ( !ruleElem.isNull() )
{
ruleCount++;
// more rules present, use the RuleRenderer
if ( ruleCount > 1 )
{
QgsDebugMsg( "more Rule elements found: need a RuleRenderer" );
needRuleRenderer = true;
break;
}
QDomElement ruleChildElem = ruleElem.firstChildElement();
while ( !ruleChildElem.isNull() )
{
// rule has filter or min/max scale denominator, use the RuleRenderer
if ( ruleChildElem.localName() == "Filter" ||
ruleChildElem.localName() == "MinScaleDenominator" ||
ruleChildElem.localName() == "MaxScaleDenominator" )
{
QgsDebugMsg( "Filter or Min/MaxScaleDenominator element found: need a RuleRenderer" );
needRuleRenderer = true;
break;
}
ruleChildElem = ruleChildElem.nextSiblingElement();
}
if ( needRuleRenderer )
{
break;
}
ruleElem = ruleElem.nextSiblingElement( "Rule" );
}
QString rendererType;
if ( needRuleRenderer )
{
rendererType = "RuleRenderer";
}
else
{
rendererType = "singleSymbol";
}
QgsDebugMsg( QString( "Instantiating a '%1' renderer..." ).arg( rendererType ) );
// create the renderer and return it
QgsRendererAbstractMetadata* m = QgsRendererRegistry::instance()->rendererMetadata( rendererType );
if ( !m )
{
errorMessage = QString( "Error: Unable to get metadata for '%1' renderer." ).arg( rendererType );
return nullptr;
}
QgsFeatureRenderer* r = m->createRendererFromSld( featTypeStyleElem, geomType );
return r;
}
