TLBinding • tldraw Docs

The set of all bindings that are available in the editor. Bindings represent relationships between shapes, such as arrows connecting to other shapes.

You can use this type without a type argument to work with any binding, or pass a specific binding type string (e.g., 'arrow') to narrow down to that specific binding type.

type TLBinding<K extends keyof TLIndexedBindings = keyof TLIndexedBindings> =
  TLIndexedBindings[K];

Example

// Check binding type and handle accordingly
function handleBinding(binding: TLBinding) {
  switch (binding.type) {
    case "arrow":
      // Handle arrow binding
      break;
    default:
      // Handle unknown custom binding
      break;
  }
}

// Narrow to a specific binding type by passing the type as a generic argument
function getArrowSourceId(binding: TLBinding<"arrow">) {
  return binding.fromId; // TypeScript knows this is a TLArrowBinding
}