Method writeAttribute

src/IECoreScene/LinkedScene.cpp:665–795

}

void LinkedScene::writeAttribute( const Name &name, const Object *attribute, double time )
{
	if ( m_readOnly )
	{
		throw Exception( "No write access to scene file!" );
	}

	if ( name == linkAttribute )
	{
		bool firstTime = !m_mainScene->hasAttribute( fileNameLinkAttribute );

		if ( firstTime )
		{
			// if it's the first time, we better check if this level already has objects, tags or children
			// and raise exceptions to prevent weird configurations...
			if ( m_mainScene->hasObject() )
			{
				throw Exception( "Links to external scenes cannot be created on locations where there's already an object saved!" );
			}
		}

		// we are creating a link!
		const CompoundData *d = runTimeCast< const CompoundData >(attribute);
		if ( !d )
		{
			throw Exception( "SceneInterface:link attribute must be of type CompoundData!" );
		}

		// open the linked scene
		int linkDepth;
		ConstDoubleDataPtr timeData = d->member< const DoubleData >( g_time );
		const StringData *fileName = d->member< const StringData >( g_fileName );
		const InternedStringVectorData *sceneRoot = d->member< const InternedStringVectorData >( g_root );
		m_linkedScene = expandLink( fileName, sceneRoot, linkDepth );
		if ( !m_linkedScene )
		{
			throw Exception( "Trying to store a broken link!" );
		}
		m_rootLinkDepth = linkDepth;

		// check for child name clashes:
		NameList mainSceneChildren;
		NameList linkedSceneChildren;

		m_mainScene->childNames( mainSceneChildren );
		m_linkedScene->childNames( linkedSceneChildren );
		std::sort( mainSceneChildren.begin(), mainSceneChildren.end() );
		std::sort( linkedSceneChildren.begin(), linkedSceneChildren.end() );

		std::set<Name> intersection;
		std::set_intersection(mainSceneChildren.begin(),mainSceneChildren.end(),linkedSceneChildren.begin(),linkedSceneChildren.end(), std::inserter(intersection,intersection.begin()) );

		if( intersection.size() )
		{
			std::string intersectionString;
			for( std::set<Name>::iterator it = intersection.begin(); it != intersection.end(); ++it )
			{
				intersectionString += " " + it->string();