Function createStore

packages/annotorious-core/src/state/Store.ts:31–420

()

const isAnnotation = <T extends Annotation>(arg: any): arg is T => arg.id !== undefined;

export const createStore = <T extends Annotation>() => {

  const annotationIndex = new Map<string, T>();

  const bodyIndex = new Map<string, string>();

  const observers: StoreObserver<T>[] = [];

  const observe = (onChange: { (event: StoreChangeEvent<T>): void }, options: StoreObserveOptions = {}) => {
    observers.push({ onChange, options });
  }

  const unobserve = (onChange: { (event: StoreChangeEvent<T>): void }) => {
    const idx = observers.findIndex(observer => observer.onChange == onChange);
    if (idx > -1)
      observers.splice(idx, 1);
  }

  const emit = (origin: Origin, changes: ChangeSet<T>) => {
    const event: StoreChangeEvent<T> = {
      origin,
      changes: {
        created: changes.created || [],
        updated: changes.updated || [],
        deleted: changes.deleted || []
      },
      state: [...annotationIndex.values()]
    };

    observers.forEach(observer => {
      if (shouldNotify(observer, event))
        observer.onChange(event);
    });
  }

  const addAnnotation = (annotation: Partial<T>, origin = Origin.LOCAL) => {
    const existing = annotation.id && annotationIndex.get(annotation.id);

    if (existing) {
      throw Error(`Cannot add annotation ${annotation.id} - exists already`);
    } else {
      const sanitized = sanitize(annotation);

      annotationIndex.set(sanitized.id, sanitized);
      sanitized.bodies.forEach(b => bodyIndex.set(b.id, sanitized.id));
      emit(origin, { created: [sanitized] });
    }
  }

  const updateOneAnnotation = (arg1: string | Partial<T>, arg2?: Partial<T> | Origin) => {
    const updated: T = typeof arg1 === 'string' ? sanitize(arg2 as Partial<T>) : sanitize(arg1);

    const oldId: string | undefined = typeof arg1 === 'string' ? arg1 : arg1.id;
    const oldValue = oldId && annotationIndex.get(oldId);

    if (oldValue) {
      const update: Update<T> = diffAnnotations(oldValue, updated);