rxact/es/stateStream/stateFactory.js

an observable application management for Javascript apps

var disposedFn = function disposedFn() {
  console.warn('You are calling function on a disposed StateStream.');
};

function stateFactory(initialState) {
  var _this = this;

  var disposed = false;
  var state = initialState;
  this.observers = [];

  this.getState = function () {
    return state;
  };

  this.next = function (updater) {
    if (disposed) {
      return;
    }

    if (typeof updater !== 'function') {
      throw new Error('Expected passing a function to emitState.');
    }

    var nextState = updater(state);
    state = nextState;
    _this.observers.forEach(function (observer) {
      observer.next(nextState);
    });
  };

  var state$ = new this.Observable(function (observer) {
    _this.observers.push(observer);

    observer.next(state);

    return {
      unsubscribe: function unsubscribe() {
        _this.observers = _this.observers.filter(function (item) {
          return item !== observer;
        });
      }
    };
  });

  this.subscriptions.push({
    unsubscribe: function unsubscribe() {
      disposed = true;
      _this.next = disposedFn;

      _this.observers.forEach(function (observer) {
        observer.complete();
      });
      _this.observers = [];
    }
  });

  return state$;
}

export default stateFactory;