thundercats/lib/Actions.js

RxJS Meets isomorphic Flux

'use strict';

Object.defineProperty(exports, '__esModule', {
  value: true
});
exports.getActionDef = getActionDef;
exports.create = create;
exports.createMany = createMany;
exports['default'] = Actions;

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { 'default': obj }; }

var _stampit = require('stampit');

var _stampit2 = _interopRequireDefault(_stampit);

var _warning = require('warning');

var _warning2 = _interopRequireDefault(_warning);

var _debug = require('debug');

var _debug2 = _interopRequireDefault(_debug);

var _rx = require('rx');

var _waitFor = require('./waitFor');

var _waitFor2 = _interopRequireDefault(_waitFor);

var __DEV__ = process.env.NODE_ENV !== 'production';
var checkDisposed = _rx.Disposable.checkDisposed;

var assign = Object.assign;
var debug = (0, _debug2['default'])('thundercats:actions');
var currentStampSpec = ['methods', 'statics', 'props', 'refs', 'init', 'compose', 'create', 'isStamp'];

var protectedProperties = ['shouldBindMethods', 'displayName', 'constructor'].join(currentStampSpec);

function getActionDef(ctx) {
  return Object.getOwnPropertyNames(ctx).filter(function (name) {
    return protectedProperties.indexOf(name) === -1 && name.indexOf('_') === -1;
  }).map(function (name) {
    return { name: name, map: ctx[name] };
  }).map(function (def) {
    if (typeof def.map !== 'function') {
      def.map = _rx.helpers.identity;
    }
    return def;
  });
}

function create(shouldBind, _ref) {
  var name = _ref.name;
  var map = _ref.map;

  var observers = [];
  var actionDisposable = new _rx.CompositeDisposable();
  var actionStart = new _rx.Subject();
  var actionEnd = new _rx.Subject();
  var maybeBound = shouldBind ? map.bind(this) : map;

  function action(value) {
    // throw if disposed observable is retried
    checkDisposed(action);
    if (action.isStopped) {
      debug('%s called after being stopped', name);
      return value;
    }

    // NOTE: if an error is thrown in the mapping function
    // this will cause the stream to collapse
    // and the action will no longer be observable
    // nor will the observers listen as they have been stopped by
    // the error
    var mapDisposable = _rx.Observable.just(value).map(maybeBound).flatMap(function (value) {
      if (_rx.Observable.isObservable(value)) {
        return value;
      }
      return _rx.Observable.just(value);
    })
    // notify of action start
    ['do'](function (value) {
      return actionStart.onNext(value);
    })
    // notify action observers
    .doOnNext(function (value) {
      return observers.forEach(function (observer) {
        return observer.onNext(value);
      });
    }).doOnCompleted(function () {
      return actionEnd.onNext();
    }).subscribe(function () {
      return debug('%s onNext', name);
    }, function (err) {
      // observables returned by the mapping function must use
      // a catch to prevent the action from collapsing the stream
      action.error = err;
      action.isStopped = true;
      action.hasError = true;

      // notify action observers of error
      observers.forEach(function (observer) {
        return observer.onError(err);
      });
      // observers will no longer listen after pushing error
      // as the stream has collapsed
      // so we remove them
      observers.length = 0;
    });

    actionDisposable.add(mapDisposable);
    return value;
  }

  action.isDisposed = false;
  action.isStopped = false;
  action.displayName = name;
  action.observers = observers;
  assign(action, _rx.Observable.prototype);

  action.hasObservers = function hasObservers() {
    // in next major version this should throw if already disposed
    // in order to better follow RxJS conventions
    //
    // checkDisposed(action);

    return !!(observers.length > 0 || actionStart.observers && actionStart.observers.length > 0);
  };

  action.waitFor = function () {
    var _arguments = arguments;

    /* istanbul ignore else */
    if (__DEV__) {
      (0, _warning2['default'])(false, 'action.waitFor is deprecated and will be removed in ' + 'the next version of thundercats');
    }
    return actionStart.flatMap(function (payload) {
      return _waitFor2['default'].apply(undefined, _arguments).map(function () {
        return payload;
      });
    });
  };

  // NOTE: not public API. May change or be removed at any time
  action.__duration = function __duration() {
    return actionStart.flatMap(actionEnd).first();
  };

  action._subscribe = function subscribeToAction(observer) {
    // in next major version this should check if action
    // has been stopped or disposed and act accordingly
    observers.push(observer);
    return new _rx.Disposable(function () {
      observers.splice(observers.indexOf(observer), 1);
    });
  };

  var subscription = new _rx.Disposable(function () {
    observers.length = 0;
    action.isDisposed = true;
    actionStart.dispose();
    actionDisposable.dispose();
  });

  action.dispose = function () {
    return subscription.dispose();
  };

  _rx.Observable.call(action);

  debug('%s created', action.displayName);
  return {
    action: action,
    subscription: subscription
  };
}

function createMany(shouldBind, instance, compositeDisposable) {
  return this.map(create.bind(instance, shouldBind)).reduce(function (ctx, _ref2) {
    var action = _ref2.action;
    var subscription = _ref2.subscription;

    compositeDisposable.add(subscription);
    ctx[action.displayName] = action;
    return ctx;
  }, {});
}

function Actions() {
  var obj = arguments.length <= 0 || arguments[0] === undefined ? {} : arguments[0];
  var shouldBind = obj.shouldBindMethods;
  var _obj$init = obj.init;
  var init = _obj$init === undefined ? [] : _obj$init;
  var _obj$props = obj.props;
  var props = _obj$props === undefined ? {} : _obj$props;
  var _obj$refs = obj.refs;
  var refs = _obj$refs === undefined ? {} : _obj$refs;
  var _obj$statics = obj.statics;
  var statics = _obj$statics === undefined ? {} : _obj$statics;

  return (0, _stampit2['default'])().init(function (_ref3) {
    var _context;

    var instance = _ref3.instance;

    var actionsDisposable = new _rx.CompositeDisposable();
    var actionMethods = (_context = getActionDef(obj), createMany).call(_context, shouldBind, instance, actionsDisposable);

    return assign(instance, actionMethods, { dispose: function dispose() {
        actionsDisposable.dispose();
      } });
  }).refs(refs).props(props)['static'](statics).init(init);
}