Function tryGet

front_end/core/common/ResolverBase.ts:41–53

* Resolve the `id`. Returns the object immediately if it can be resolved, * and otherwise waits for the object to appear and calls `callback` once * it is resolved.

(id: Id, callback: (t: T) => void)

   * it is resolved.
   */
  tryGet(id: Id, callback: (t: T) => void): T|null {
    const obj = this.getForId(id);
    if (!obj) {
      const swallowTheError = (): void => {};
      void this.getOrCreatePromise(id).catch(swallowTheError).then(obj => {
        if (obj) {
          callback(obj);
        }
      });
      return null;
    }
    return obj;
  }

  /**
   * Aborts all waiting and rejects all unresolved promises.