addExtension method

void addExtension(NodeFlowExtension<T> extension)

Registers an extension with this controller.

The extension's NodeFlowExtension.attach method is called immediately. Throws a StateError if an extension with the same ID is already registered.

Example:

controller.addExtension(UndoRedoExtension<MyData>());

Implementation

void addExtension(NodeFlowExtension<T> extension) {
  if (_extensions.any((e) => e.id == extension.id)) {
    throw StateError(
      'Extension "${extension.id}" is already registered. '
      'Remove it first before adding a new instance.',
    );
  }
  _extensions.add(extension);
  extension.attach(this);
}