funcSubject.js

//   Copyright 2014-2015 François de Campredon
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.

'use strict';


var Rx = require('rx');

/**
 * Factory that allows you to create your custom `FuncSuject`
 * 
 * example: 
 * 
 * var myFuncSubject = FuncSubject.factory(MyCustomSubject, (val1, val2) => val1 + val2, ...arguments);
 */
function factory(BaseClass, mapFunction) {
  function subject(value) {
    if (typeof mapFunction === 'function') {
      value = mapFunction.apply(undefined, arguments);
    } else if (typeof mapFunction !== 'undefined') {
      value = mapFunction;
    }
    subject.onNext(value);
    return value;
  }
  
  for (var key in BaseClass.prototype) {
    subject[key] = BaseClass.prototype[key];
  }

  BaseClass.apply(subject, [].slice.call(arguments, 2));

  return subject;
}
exports.factory = factory;


/**
 * Create a simple 'function' that is also a RxJS Subject. 
 * Calling the function will be equivalent to calling
 * the 'onNext' method.
 * 
 * example:
 * 
 * var eventHandler = FuncSubject.create();
 * eventHandler.subscribe(function (val) {
 *   console.log(val);
 * });
 * 
 * eventHandler('hello'); // log hello
 * eventHandler.onNext('world'); // log world
 * 
 */
function create(mapFunction) {
  return factory(Rx.Subject, mapFunction);
}

exports.create = create;

/**
 * Create a simple 'function' that is also a RxJS BehaviorSubject. 
 * Calling the function will be equivalent to calling
 * the 'onNext' method.
 * 
 * example:
 * 
 * var eventHandler = FuncSubject.behavior('hello');
 * eventHandler.subscribe(function (val) {
 *   console.log(val);
 * }); // log hello
 * 
 * eventHandler.onNext('world'); // log world
 * 
 * eventHandler.subscribe(function (val) {
 *   console.log(val);
 * }); // log world
 * 
 */
function behavior(initialValue, mapFunction) {
  return factory(Rx.BehaviorSubject, mapFunction, initialValue);
}

exports.behavior = behavior;

/**
 * Create a simple 'function' that is also a RxJS AsyncSubject.
 */
function async(mapFunction) {
  return factory(Rx.AsyncSubject, mapFunction);
}

exports.async = async;

/**
 * Create a simple 'function' that is also a RxJS ReplaySubject.
 */
function replay(bufferSize, mapFunction) {
  return factory(Rx.ReplaySubject, mapFunction, bufferSize);
}
exports.replay = replay;

exports.behavior = behavior;