NodeDecorator

The node can be decorated in various ways. addConstant decorates the node's lookup to return the same instance for each node.

graph.decorator.nodes.sizeConstraintProvider.addConstant(
  new ConstantSizeConstraintProvider(),
)

addConstant with a predicate decorates the node's lookup only to return the same instance for each node for which the predicate returns true.

graph.decorator.nodes.sizeConstraintProvider.addConstant(
  (node) => node.tag !== null,
  new ConstantSizeConstraintProvider(),
)

addFactory calls the provided factory method to return a new instance of the queried type created for the given node or for nodes for which the predicate returns true, respectively:

graph.decorator.nodes.sizeConstraintProvider.addFactory(
  (node) => new CustomSizeConstraintProvider(node),
)
graph.decorator.nodes.sizeConstraintProvider.addFactory(
  (node) => node.tag !== null,
  (node) => new CustomSizeConstraintProvider(node),
)

addWrapperFactory calls the provided factory method to return a new instance of the queried type which wraps the default implementation, once for all nodes and once only for nodes for which the predicate returns true.

graph.decorator.nodes.sizeConstraintProvider.addWrapperFactory(
  (node, originalProvider) =>
    new SizeConstraintProviderWrapper(node, originalProvider),
)
graph.decorator.nodes.sizeConstraintProvider.addWrapperFactory(
  (node) => node.tag !== null,
  (node, originalProvider) =>
    new SizeConstraintProviderWrapper(node, originalProvider),
)

Finally hide hides the default implementation by letting the lookup always return null for all nodes and for nodes for which the predicate returns true, respectively

graph.decorator.nodes.sizeConstraintProvider.hide()
graph.decorator.nodes.sizeConstraintProvider.hide(
  (node) => node.tag !== null,
)

Each of these methods returns a IContextLookupChainLink which can be used to remove the modified behavior again:

registerLookup(graph: IGraph): void {
  this.chainLink =
    graph.decorator.nodes.sizeConstraintProvider.addFactory(
      (node) => new CustomSizeConstraintProvider(node),
    )!
}

deregisterLookup(graph: IGraph): void {
  graph.decorator.nodes.remove(this.chainLink)
}