Buffalo 学习笔记- buffalo.js 源代码注释(一)

Buffalo 学习笔记- buffalo.js 源代码注释(一)

注： 如果转载 请注明 

原文地址: http://blog.csdn.net/jianglike18/archive/2009/04/14/4073907.aspx

 

/*
* 申明 改代码的所有权归原作者，
  本人只是给该代码加入自己理解的注释 ，如果你有任何疑问都可以

  留言互相讨论
*
*/
// create Buffalo object with prototype.js package
var Buffalo = Class.create();
Buffalo.BOCLASS="_BUFFALO_OBJECT_CLASS_";
Buffalo.VERSION="2.0";

Buffalo.prototype = {
 //创建 Buffalo 对象的时候会调用initialize方法
 initialize: function(gateway, async, events, options) {
  this.gateway = gateway;
  this.transport = null;
  if (typeof(async) == 'undefined') {
   this.async = true;
  } else {
   this.async = async;
  }
  this.currentCallback = new Function();
  this.setEvents(events);
  this.queue = [];
  this.requesting = false;
  this.options = {timeout:30000};
  //扩展 options 属性 使用了 prototype.js库的函数
  Object.extend(this.options, options || {});
 },
 getGateway : function() { return this.gateway;},

//设置调用java服务的相关事项
 setEvents: function(events) {
  this.events = {
   onLoading: Buffalo.Default.showLoading,
   onFinish: new Function(),
   onException: null,
   onError: Buffalo.Default.showError,
   onTimeout: new Function()
  };
  Object.extend(this.events, events || {});
 },
 
 //远程调用 URL : 远程的调用URL，
 _remoteCall: function(url, buffaloCall, callback) {
  this.requesting = true;
  //创建 httpRequest请求
  this.transport = XmlHttp.create();
  try {
   // 打开远程地址.指定 同步或者异步 和 POST方式
   this.transport.open("POST", url, this.async);
   
   //设置相关的请求头信息
   this.transport.setRequestHeader("X-Buffalo-Version", Buffalo.VERSION);
   
   this.transport.setRequestHeader("Content-Type", "text/xml;charset=utf-8");
   //发送数据
   this.transport.send(buffaloCall.xml());
  } catch (e) {
   this.events.onError(this.transport);
   this.events["onLoading"](false);
   return;
  }
  this.requestTime = new Date();
  // prototype.js 库的一定间隔时间上重复调用一个方法
  this.timeoutHandle = new PeriodicalExecuter(this._timeoutChecker.bind(this), 0.5);
  
  this.currentCallback = callback;
  //异步调用
  if (this.async) {
   this.transport.onreadystatechange = this.onStateChange.bind(this);
   this.events["onLoading"](true);
  } else { //同步调用
   this.response();
  }
 },
 //判断是否超时
 _timeoutChecker: function() {
  if ((new Date() - this.requestTime) > this.options.timeout) {
   this.events["onTimeout"]();
   this.timeoutHandle.stop();
  }
 },
    //
 nextRemoteCall : function() {
  if (this.queue.length <= 0) return ;
  var command = this.queue.shift();
  this._remoteCall(command.url, command.call, command.callback);
 },
 
   //进行远程调用(可以将N个远程调用的服务放入 queue 数组中 )
 remoteCall: function(service, params, callback) {
  var serviceMethodPair = this._splitServiceMethod(service);
  var newUrl = this.gateway+"/buffalo/"+serviceMethodPair[0];
  var call = new Buffalo.Call(serviceMethodPair[1]);
  //将参数添加到 Buffalo.Call的
  for (var i = 0; i < params.length; i++) {
   call.addParameter(params[i]);
  }
  this.queue.push({url:newUrl, call: call, callback: callback});
  if (!this.requesting) {
   this.nextRemoteCall();
  }
 },
 
 //分离出远程调用的服务类ID（如果BUFFALO是被Springl继承那么，那么应该在Spring的配置文件中有定义） 和 服务类的方法
 _splitServiceMethod: function(service) {
  var idx = service.lastIndexOf(".");
  var serviceId = service.substring(0,idx);
  var method = service.substring(idx+1,service.length);
  return [serviceId, method];
 },
 
 //当服务器有反应的时候调用该函数
 onStateChange: function(){
  if (this.transport.readyState == 4) {
   this.response();
  }
 },
 //处理服务器的返回信息
 response : function() {
 
  this.timeoutHandle.stop();//停止超时判断函数的执行
  this.events["onLoading"](false);//隐藏加载等待页面
  if (this.transport.responseText && this.transport.status == '200') {
   var reply = new Buffalo.Reply(this.transport);
   if (reply.isFault()) {
     if (this.events["onException"]) {
       this.events["onException"](reply.getResult());
     } else {
       Buffalo.Default.showException(reply.getResult());
       this.currentCallback(reply); 
     }
   } else {
     this.currentCallback(reply); 
   }
   this.events["onFinish"](reply);
   this.requesting = false;
   this.nextRemoteCall();
  } else {
   this.events["onError"](this.transport);
   this.requesting = false;
  }
 }
}

// 148~209 行 定义了 显示加载 出错 异常 超时 等相关状态的信息
Buffalo.Default = {
 loadingPane: null,
 errorPane: null,
 exceptionPane: null,
 //显示加载的等待页面 这个可以根据实际的情况进行修改
 showLoading : function(state) {
  this.loadingPane = $("buffalo_loading");
  if (this.loadingPane == null) {
   var el = document.createElement('DIV');
   el.setAttribute("id","buffalo_loading");
   el.style.cssText="display:none;font-family:Verdana;font-size:11px;border:1px solid #00CC00;background-color:#A4FFA4;padding:1px;position:absolute; right:1px; top:1px; width:110px; height:14px; z-index:10000";
   el.innerHTML="buffalo loading... ";
   document.body.appendChild(el);
   this.loadingPane = el;
  }
  if (state) {
   this.loadingPane.style.display="block";
   this.loadingPane.style.top = document.body.scrollTop+1;
  } else {
   this.loadingPane.style.display="none";
  }
 },
 
 showError: function(transport) {
  this.errorPane = $("buffalo_error");
  if (this.errorPane == null) {
   var el = document.createElement('DIV');
   el.setAttribute("id","buffalo_error");
   el.style.cssText="font-size:11px;border:4px solid #FF3333;background-color:#fff;padding:4px;position:absolute;overflow:auto; right:10px; top:10px; width:500px; height:300px; z-index:1";
   el.innerHTML="<h2>Error: " + transport.status+" - "+transport.statusText+"</h2>";
   el.innerHTML+="<textarea style='width:96%;height:80%'>"+transport.responseText.stripTags()+"</textarea>";
        el.onclick=function(){ el.style.display="none"; }
   document.body.appendChild(el);
   this.errorPane = el;
  } else {
   this.errorPane.style.display = "block";
  }
 },
 
 showException: function(faultObj) {
  this.exceptionPane = $("buffalo_exception");
  if (this.exceptionPane == null) {
   var el = document.createElement('DIV');
   el.setAttribute("id","buffalo_exception");
   el.style.cssText="font-size:11px;border:4px solid #FFFF33;background-color:#fff;padding:4px;position:absolute;overflow:auto; right:10px; top:10px; width:300px; height:100px; z-index:1";
   el.innerHTML ="<h2>Exception: " + faultObj.code+"</h2>";
   el.innerHTML += "Code: "+faultObj.code+"<br/>";
   el.innerHTML += "Message: "+faultObj.message+"<br/>";
   el.innerHTML += "Detail: " + faultObj.detail;
        el.onclick=function(){ el.style.display="none"; }
   document.body.appendChild(el);
   this.exceptionPane = el;
  } else {
   this.exceptionPane.style.display = "block";
  }
 },
 
 showTimeout: function() {
  alert("timeout!");
 }
}