eventric/build/node/src/pub_sub/pub_sub.js

Build JavaScript applications with Behaviour-driven Domain Design. Based on DDD, BDD, CQRS and EventSourcing.

var PubSub,
  __slice = [].slice;

PubSub = (function() {
  function PubSub() {
    this._subscribers = [];
    this._subscriberId = 0;
    this._nextTick = function() {
      var args;
      args = 1 <= arguments.length ? __slice.call(arguments, 0) : [];
      return setTimeout.apply(null, args);
    };
  }

  PubSub.prototype.subscribe = function(eventName, subscriberFn) {
    var subscriber;
    subscriber = {
      eventName: eventName,
      subscriberFn: subscriberFn,
      subscriberId: this._getNextSubscriberId()
    };
    this._subscribers.push(subscriber);
    return subscriber.subscriberId;
  };

  PubSub.prototype.subscribeAsync = function(eventName, subscriberFn) {
    var subscriber;
    subscriber = {
      eventName: eventName,
      subscriberFn: subscriberFn,
      subscriberId: this._getNextSubscriberId(),
      isAsync: true
    };
    this._subscribers.push(subscriber);
    return subscriber.subscriberId;
  };

  PubSub.prototype.publish = function(eventName, payload, callback) {
    var executeNextHandler, subscribers;
    if (callback == null) {
      callback = function() {};
    }
    subscribers = this._getRelevantSubscribers(eventName);
    executeNextHandler = (function(_this) {
      return function() {
        if (subscribers.length === 0) {
          return callback();
        } else {
          subscribers.shift().subscriberFn(payload, function() {});
          return _this._nextTick(executeNextHandler, 0);
        }
      };
    })(this);
    return this._nextTick(executeNextHandler, 0);
  };

  PubSub.prototype.publishAsync = function(eventName, payload, callback) {
    var executeNextHandler, subscribers;
    if (callback == null) {
      callback = function() {};
    }
    subscribers = this._getRelevantSubscribers(eventName);
    executeNextHandler = (function(_this) {
      return function() {
        var subscriber;
        if (subscribers.length === 0) {
          return callback();
        } else {
          subscriber = subscribers.shift();
          if (subscriber.isAsync) {
            return subscriber.subscriberFn(payload, function() {
              return setTimeout(executeNextHandler, 0);
            });
          } else {
            subscriber.subscriberFn(payload);
            return _this._nextTick(executeNextHandler, 0);
          }
        }
      };
    })(this);
    return this._nextTick(executeNextHandler, 0);
  };

  PubSub.prototype._getRelevantSubscribers = function(eventName) {
    if (eventName) {
      return this._subscribers.filter(function(x) {
        return x.eventName === eventName;
      });
    } else {
      return this._subscribers;
    }
  };

  PubSub.prototype.unsubscribe = function(subscriberId) {
    return this._subscribers = this._subscribers.filter(function(x) {
      return x.subscriberId !== subscriberId;
    });
  };

  PubSub.prototype._getNextSubscriberId = function() {
    return this._subscriberId++;
  };

  return PubSub;

})();

module.exports = PubSub;