yadda/lib/EventBus.js

A true BDD framework for JavaScript

'use strict';

var $ = require('./Array');
var fn = require('./fn');
var event_bus = new EventBus();

// A communication channel between event emitters and event listeners
function EventBus() {
  var event_handlers = $();

  this.send = function (event_name, event_data, next) {
    if (arguments.length === 1) return this.send(event_name, {});
    if (arguments.length === 2 && fn.is_function(event_data)) return this.send(event_name, {}, event_data);
    notify_handlers(event_name, event_data);
    next && next();
    return this;
  };

  this.on = function (event_pattern, callback) {
    event_handlers.push({ pattern: event_pattern, callback: callback });
    return this;
  };

  var notify_handlers = function (event_name, event_data) {
    find_handlers(event_name).each(function (callback) {
      callback({ name: event_name, data: event_data });
    });
  };

  var find_handlers = function (event_name) {
    return event_handlers
      .find_all(function (handler) {
        return new RegExp(handler.pattern).test(event_name);
      })
      .collect(function (handler) {
        return handler.callback;
      });
  };
}

function instance() {
  return event_bus;
}

module.exports = {
  instance: instance,
  ON_SCENARIO: '__ON_SCENARIO__',
  ON_STEP: '__ON_STEP__',
  ON_EXECUTE: '__ON_EXECUTE__',
  ON_DEFINE: '__ON_DEFINE__',
};