梅子开源js框架研究（1）

/**//*---------------------------------------------------------------------------*
|  Subject: JavaScript Framework
|  Author:  meizz
|  Created: 2005-02-27
|  Version: 2007-06-06
|-----------------------------------
|  MSN:[e-mail] QQ:112889082 Copyright(c) meizz
|  http://www.meizz.com/jsframework/ MIT-style license
|  The above copyright notice and this permission notice shall be
|  included in all copies or substantial portions of the Software
*---------------------------------------------------------------------------*/

if( typeof(System) != "function" && typeof(Using) != "function" )
...{

    var S = window.System = function()
    ...{
        this.setHashCode();
    }

    S.debug = false; //false
    S.currentVersion = "20070606";
    
    S._codebase=...{};

    try
    ...{
        if(window!=parent && parent.System && parent.System._codebase)
            S._codebase=parent.System._codebase;
        else if(typeof(opener)!="undefined"&&opener.System&&opener.System._codebase)
            S._codebase=opener.System._codebase;
        else if(typeof(dialogArguments)!="undefined" && dialogArguments.System)
            S._codebase=dialogArguments.System._codebase;
    }
    catch(ex)
    ...{}

    var t=document.getElementsByTagName("SCRIPT");
    t=( S.scriptElement=t[t.length-1]).src.replace(///g,"/" );
    
    S.extend=function(d,s)
    ...{
        for(var i in s)
            d[i]=s[i];
        return d;
    };
    
    S.path=(t.lastIndexOf("/")<0) ? "." : t.substring(0, t.lastIndexOf("/"));
    S.resourcePath=S.path +"/System/_resource";
    S.hashCounter=0;
    S.NOT_SUPPORTED_XMLHTTP="Your browser do not support XMLHttp";
    
    S.getUniqueId=function()
    ...{
        return "mz_"+(System.hashCounter++).toString(36);
    };

    S.toHashCode=function(e)
    ...{
        if(typeof(e.hashCode)!="undefined")
        ...{
            return e.hashCode;
        }
        
        return (e.hashCode=System.getUniqueId());
    };

    S.supportsXmlHttp=function()
    ...{
        return "object"==typeof(System.xhr||(System.xhr=new XMLHttpRequest()));
    };

    S._getPrototype=function(ns, argu)
    ...{
        if(typeof(System._prototypes[ns])=="undefined")
            return new System();
            
        for(var a=[],i=0;i<argu.length;i++)
            a[i]="argu["+i+"]";
            
        return eval("new (System._prototypes['"+ns+"'])("+a.join(",")+")");
    };

    S.ie=navigator.userAgent.indexOf("MSIE")>0 && !window.opera;

    S.alert=function(msg)
    ...{
        if(System.debug)
            alert(msg);
    };

    S._userdata=(System.ie && !System.debug);S._parseResponse=function(ns,s)
    ...{
        if(s==null||s.charAt(0)==" ")
        ...{
            System.alert("Maybe file encoding isn't ANSI or UTF-8");return ""
        }
        
        if(s.charAt(0)=="ï")s=s.substr(3); //for firefox
            s=s.replace(/(^| )s*//+s*((Using|Import|Include)(("|'))/g,"$1$2");
            
        if(System._userdata)
            System.saveUserData(ns,s);
            
        return s;
    };

    if( !window.XMLHttpRequest && window.ActiveXObject )
    {
        window.XMLHttpRequest=function()
        {
            for(var i=0,a=['MSXML3','MSXML2','Microsoft'];i            {
                try
                {
                    return new ActiveXObject(a[i]+'.XMLHTTP')
                } 
                catch(ex){}
            }
            System.xhr="mz";
            throw new Error(System.NOT_SUPPORTED_XMLHTTP);
        }
    }

    S.load=function(namespace, path)
    {
        var x,ns=namespace,S=System; 
        path=S._mapPath(ns, path);
        
        if( S._userdata && /.js$/i.test(path) && ( x=S.loadUserData(ns) ) )
            return (S._codebase[ns]="//from userdata "+ x);
        try
        ...{
            if(S.supportsXmlHttp())
            ...{
                x=S.xhr; 
                x.open("GET",path,false); 
                x.send(null);
                if (x.readyState==4)
                ...{
                    if(x.status==0||/^file:/i.test(path))
                        return S._parseResponse(ns,x.responseText);
                    else if(x.status==200)
                        return S._parseResponse(ns,x.responseText);
                    else if(x.status==404)
                        S.alert(ns+" File not found");
                    else 
                        throw new Error(x.status +": "+ x.statusText);
                }
            }
            else S.alert(S.NOT_SUPPORTED_XMLHTTP);
        }
        catch(ex)
        ...{
            S.alert(ns+" "+ex.message);
        }
        return "";
    };

    S._exist=function(ns, path)
    ...{
        if(typeof(System._existences[ns])=="undefined") 
            return false;
        return System._existences[ns]==System._mapPath(ns,path);
    };

    S._mapPath = function(ns, path)
    ...{
        if(typeof(path)=="string" && path.length>3) 
            return path;
        var p=System.path +"/"+ ns.replace(/./g,"/")+".js";
        
        return p+((typeof(path)=="undefined"||path) ? "" : "?t="+Math.random());
    };

    window.Using = function(namespace,path,rename)
    ...{
        var N=namespace,C=N.substr(N.lastIndexOf(".")+1),S=System,i=S._prototypes;
        
        if(S._exist(N,path))
        ...{
            if(window[C]!=i[N])
                window[C]=i[N];
            return
        }
        
        if(!/((^|.)[w_$]+)+$/.test(N))
            throw new Error(N+" nonstandard namespace")
        
        for(var s,e,c=N+".",i=c.indexOf(".");i>-1;i=c.indexOf(".",i+1))
        ...{
            e=c.substring(0,i);
            s=(e.indexOf(".")==-1) ? "window['"+e+"']" : e;
            
            if(e&&typeof(eval(s))=="undefined")
                eval(s+"=function(){return System._getPrototype('"+e+"',arguments)}");
        }
        
        if(typeof(S._codebase[N])!="string"&&(s=S.load(N,path))) 
        ...{
            S._codebase[N]=s+"; System._prototypes['"+N+"']=window['"+(rename||C)+"']="+C;
        }
            
        s="";
        S._existences[N]=S._mapPath(N, path);
        
        if("string"==typeof (s=System._codebase[N]))
        ...{
            try
            ...{
                (new Function(s))()
            }
            catch(e)
            ...{
                System.alert("Syntax error on load "+ N +" "+ e.message);
            }
        }
        //alert(System._codebase[namespace])
    };
    
    window.Import=function(namespace,path,rename)
    ...{
        Using(namespace,path,rename)
    };
    
    window.Instance=function(hashCode)
    ...{
        return System._instances[hashCode]
    };
    
    window.Include=function(namespace, path)
    ...{
        var N=namespace,c,S=System,X=S.supportsXmlHttp();
        
        if(S._exist(N,path))
            return;
            
        if(!/((^|.)[w_$]+)+$/.test(N))
            throw new Error(N+" nonstandard namespace")
        
        if(typeof(S._codebase[N])!="string")
        ...{
            if(X&&(c=S.load(N,path)))
            ...{
                S._codebase[N]=c;
            }
        }
        
        S._existences[N]=S._mapPath(N,path);
        
        var B=(typeof(S._codebase[N])=="string");
        try
        ...{
            if(window.execScript&&B)
                window.execScript(S._codebase[N]);
            else
            ...{
                var s=document.createElement("SCRIPT");
                s.type="text/javascript";
                
                if(B)
                    s.innerHTML="eval(System._codebase['"+N+"']);";
                else
                    s.src=S._existences[N]=S._mapPath(N,path);
                    
                document.getElementsByTagName("HEAD")[0].appendChild(s);
                s=null;
            }
        }
        catch(B)
        ...{
            S.alert("Syntax error on include "+N+" "+ B.message);
        }
    };

    Function.prototype.Extends=function(SuperClass,ClassName)
    ...{
        var op=this.prototype, i, p=this.prototype=new SuperClass();
        if(ClassName)
            p._className=ClassName; 
            
        for(i in op)
            p[i]=op[i];
            
        if(p.hashCode)
            delete System._instances[p.hashCode];
            
        return p;
    };
    
    S._prototypes=
    ...{
        "System":S,"System.Object":S,"System.Event":System.Event
    };

    S._existences=
    ...{
        "System.Event":S._mapPath("System.Event"),"System":S._mapPath("System"),"System.Object":S._mapPath("System.Object")
    };

    var t=System.Extends(Object, "System");
    S.Object=S;
    S._instances=...{};

    t.addEventListener=function(type, handle)
    ...{
        if(typeof(handle)!="function")
            throw new Error(this+" addEventListener: "+handle+" is not a function");
        if(!this._listeners) 
            this._listeners=...{};
        var id=System.toHashCode(handle), t=this._listeners; 
        if(typeof(t[type])!="object")
            t[type]=...{}; 
        t[type][id]=handle;
    };

    t.removeEventListener=function(type, handle)
    ...{
        if(!this._listeners)
            this._listeners=...{};
        var t=this._listeners;
        if(!t[type]) 
            return; 
        var id=System.toHashCode(handle);
        if( t[type][id])
            delete t[type][id];
        if(t[type])
            delete t[type];
    };

    t.dispatchEvent=function(evt)
    ...{
        if(!this._listeners)
            this._listeners=...{};
            
        var i, t =this._listeners, p =evt.type;
        evt.target=evt.srcElement=evt.target||evt.srcElement||this;
        evt.currentTarget=this;
        
        if(this[p])
            this[p](evt);
        
        if(typeof(t[p])=="object") 
        ...{
            for(i in t[p]) 
                t[p][i].call(null, evt);
        }
        
        delete evt.target;        
        delete evt.currentTarget;
        delete evt.srcElement;
        return evt.returnValue;
    };

    t.dispose=function()
    ...{
        if(this.hashCode) 
        ...{
            delete System._instances[this.hashCode];
        }
        
        for(var i in this)
        ...{
            if(typeof(this[i])!="function")
            ...{
                delete this[i];
            }
        }
    };

    t.setHashCode=function()
    ...{
        System._instances[(this.hashCode=System.getUniqueId())]=this;
    };

    t.getHashCode=function()
    ...{
        if(!this.hashCode)
            this.setHashCode();
        return this.hashCode;
    };

    t.decontrol=function()
    ...{
        delete System._instances[this.hashCode];
    }

    t.toString=function()
    ...{
        return "[object "+(this._className||"Object")+"]";
    };

    S.getType=function(e)
    ...{
        if(typeof(e) != "object")
            return typeof(e);
        if(e == "[object Object]")
            return "object";
            
        if(/[objects+([^s]]+)]/.test(e))
            return RegExp.$1;
        else 
            return "object";
    };

    System.Event=function(type)
    ...{
        this.type=type;
    };

    t=System.Event.Extends(System,"System.Event");
    t.returnValue=true;
    t.cancelBubble=false;
    t.target=t.currentTarget=t.srcElement=null;

    if(System.ie)
    ...{
        //在IE中使用userdata
        S.scriptElement.addBehavior("#default#userdata");
        
        S.saveUserData=function(key, value)
        ...{
            try
            ...{
                var d=new Date();
                d.setDate(d.getDate()+3);//3 day
                var t=System.scriptElement;
                t.load(key.replace(/W/g,"_"));
                t.setAttribute("code",value);
                t.setAttribute("version",System.currentVersion);
                t.expires=d.toUTCString(); 
                t.save(key.replace(/W/g,"_"));
                
                return t.getAttribute("code");
            }
            catch(ex)...{}
        }
        
        S.loadUserData=function(key)
        ...{
            try
            ...{
                var t=System.scriptElement;
                t.load(key.replace(/W/g,"_"));
                if( System.currentVersion!=t.getAttribute("version") )
                ...{
                    if(t.getAttribute("code"))
                        System.deleteUserData(key);
                    return "";
                }
                return t.getAttribute("code");
            }
            catch(ex)...{return ""}
        }
        
        S.deleteUserData=function(key)
        ...{
            try
            ...{
                var t=System.scriptElement;
                t.load(key.replace(/W/g,"_"));
                t.expires=new Date(315532799000).toUTCString();
                t.save(key.replace(/W/g, "_"));
            }
            catch(ex)...{}
        }
    } 
    
    S=t=null;
    
    try
    ...{
        if(window.opera) 
            Include("System.Plugins.Opera");
            
        Include("System.Global");
        
        Include("Csdn.Common");
    }
    catch(ex)...{}
}

 
以上是梅子的开源框架中，最经典的1段代码，摘自jsframework.js.
主要完成了有以下功能：
1.引用框架之后，要使用框架中的js，直接试用Using("System.Global");9可以自动载入页面。而include虽然也  可以使用，但是区别在于，using的是js中的"类"，而include的只是松散的js代码集合。
2.开发时的debug状态，发布的时候改为false.
3.定义version字段，当发现版本号不正确时，自动的删除原来存在UserData中的xml文件，而加载入新的js文件。
4.定义js加载到客户端以后的时间（默认3天）

经梅子允许开放以上代码。

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