梅子开源js框架研究（1）

/**//*---------------------------------------------------------------------------*


|  Subject: JavaScript Framework


|  Author:  meizz


|  Created: 2005-02-27


|  Version: 2007-06-06


|-----------------------------------


|  MSN:huangfr@msn.com 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

            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"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
)


                window[C]=i
;


            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
)!="string"&&(s=S.load(N,path))) 




        ...{


            S._codebase
=s+"; System._prototypes['"+N+"']=window['"+(rename||C)+"']="+C;


        }


            


        s="";


        S._existences
=S._mapPath(N, path);


        


        if("string"==typeof (s=System._codebase
))




        ...{


            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
)!="string")




        ...{


            if(X&&(c=S.load(N,path)))




            ...{


                S._codebase
=c;


            }


        }


        


        S._existences
=S._mapPath(N,path);


        


        var B=(typeof(S._codebase
)=="string");


        try




        ...{


            if(window.execScript&&B)


                window.execScript(S._codebase
);


            else




            ...{


                var s=document.createElement("SCRIPT");


                s.type="text/javascript";


                


                if(B)


                    s.innerHTML="eval(System._codebase['"+N+"']);";


                else


                    s.src=S._existences
=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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