multicast.js

  var MulticastObservable = (function (__super__) {
    inherits(MulticastObservable, __super__);
    function MulticastObservable(source, fn1, fn2) {
      this.source = source;
      this._fn1 = fn1;
      this._fn2 = fn2;
      __super__.call(this);
    }

    MulticastObservable.prototype.subscribeCore = function (o) {
      var connectable = this.source.multicast(this._fn1());
      return new BinaryDisposable(this._fn2(connectable).subscribe(o), connectable.connect());
    };

    return MulticastObservable;
  }(ObservableBase));

  /**
   * Multicasts the source sequence notifications through an instantiated subject into all uses of the sequence within a selector function. Each
   * subscription to the resulting sequence causes a separate multicast invocation, exposing the sequence resulting from the selector function's
   * invocation. For specializations with fixed subject types, see Publish, PublishLast, and Replay.
   *
   * @example
   * 1 - res = source.multicast(observable);
   * 2 - res = source.multicast(function () { return new Subject(); }, function (x) { return x; });
   *
   * @param {Function|Subject} subjectOrSubjectSelector
   * Factory function to create an intermediate subject through which the source sequence's elements will be multicast to the selector function.
   * Or:
   * Subject to push source elements into.
   *
   * @param {Function} [selector] Optional selector function which can use the multicasted source sequence subject to the policies enforced by the created subject. Specified only if <paramref name="subjectOrSubjectSelector" is a factory function.
   * @returns {Observable} An observable sequence that contains the elements of a sequence produced by multicasting the source sequence within a selector function.
   */
  observableProto.multicast = function (subjectOrSubjectSelector, selector) {
    return isFunction(subjectOrSubjectSelector) ?
      new MulticastObservable(this, subjectOrSubjectSelector, selector) :
      new ConnectableObservable(this, subjectOrSubjectSelector);
  };