高手来帮忙看下，这段JS代码中的回调函数怎么控制的

天天么么哒 2012-01-27 06:39:27

通过下面的这个函数，我想知道obj.responseText的值可以在客户端控制么？？

<form id="frmbox" method="post" action="/ajaxaction.php"></form>

function AjaxSubmit() {

            var ajax = new AJAXRequest();

            ajax.postf("frmbox", Callback);

        }

function Callback(obj) 

        {

            var a = obj.responseText;

            result = 0;

            if (!isNaN(a))    result = parseInt(a);

        }

function AJAXRequest() {

	var xmlPool=[],objPool=[],AJAX=this,ac=arguments.length,av=arguments;

	var xmlVersion=["MSXML2.XMLHTTP","Microsoft.XMLHTTP"];

	var ec=emptyFun=function(){};

	av=ac>0?typeof(av[0])=="object"?av[0]:{}:{};

	var encode=$GEC(av.charset+"");

	var prop=['url','content','method','async','timeout','ontimeout','onrequeststart','onrequestend','oncomplete','onexception'];

	var defval=['','','GET',true,3600000,ec,ec,ec,ec,ec],l=prop.length;

	while(l--){this[prop[l]]=getp(av[prop[l]],defval[l]);}

	if(!getObj()) return false;

	function getp(p,d) { return p!=undefined?p:d; }

	function getObj() {

		var i,j,tmpObj;

		for(i=0,j=xmlPool.length;i<j;i++) if(xmlPool[i].readyState==0||xmlPool[i].readyState==4) return xmlPool[i];

		try { tmpObj=new XMLHttpRequest; }

		catch(e) {

			for(i=0,j=xmlVersion.length;i<j;i++) {

				try { tmpObj=new ActiveXObject(xmlVersion[i]); } catch(e2) { continue; }

				break;

			}

		}

		if(!tmpObj) return false;

		else { xmlPool[xmlPool.length]=tmpObj; return xmlPool[xmlPool.length-1]; }

	}

	function $(id){return document.getElementById(id);}

	function $N(d){var n=d*1;return(isNaN(n)?0:n);}

	function $VO(v){return(typeof(v)=="string"?(v=$(v))?v:false:v);}

	function $GID(){return((new Date)*1);}

	function $SOP(id,ct){objPool[id+""]=ct;}

	function $LOP(id){return(objPool[id+""]);}

	function $SRP(f,r,p){return(function(s){s=f(s);for(var i=0;i<r.length;i++) s=s.replace(r[i],p[i]);return(s);});}

	function $GEC(cs){

		if(cs.toUpperCase()=="UTF-8") return(encodeURIComponent);

		else return($SRP(escape,[/\+/g],["%2B"]));

	}

	function $ST(obj,text) {

		var nn=obj.nodeName.toUpperCase();

		if("INPUT|TEXTAREA|OPTION".indexOf(nn)>-1) obj.value=text;

		else try{obj.innerHTML=text;} catch(e){};

	}

	function $CB(cb) {

		if(typeof(cb)=="function") return cb;

		else {

			cb=$VO(cb);

			if(cb) return(function(obj){$ST(cb,obj.responseText);});

			else return this.oncomplete; }

	}

	function $GP(p,v,d,f) {

		var i=0;

		while(i<v.length){p[i]=v[i]?f[i]?f[i](v[i]):v[i]:d[i];i++;}

		while(i<d.length){p[i]=d[i];i++;}

	}

	function send(purl,pc,pcbf,pm,pa) {

		var ct,ctf=false,xmlObj=getObj(),ac=arguments.length,av=arguments;

		if(!xmlObj) return false;

		var pmp=pm.toUpperCase()=="POST"?true:false;

		if(!pm||!purl) return false;

		var ev={url:purl, content:pc, method:pm};

		purl+=(purl.indexOf("?")>-1?"&":"?")+"timestamp="+$GID();

		xmlObj.open(pm,purl,pa);

		AJAX.onrequeststart(ev);

		if(pmp) xmlObj.setRequestHeader("Content-Type","application/x-www-form-urlencoded");

		ct=setTimeout(function(){ctf=true;xmlObj.abort();},AJAX.timeout);

		var rc=function() {

			if(ctf) { AJAX.ontimeout(ev); AJAX.onrequestend(ev); }

			else if(xmlObj.readyState==4) {

				ev.status=xmlObj.status;

				try{ clearTimeout(ct); } catch(e) {};

				try{ if(xmlObj.status==200) pcbf(xmlObj); else AJAX.onexception(ev); }

				catch(e) { AJAX.onexception(ev); }

				AJAX.onrequestend(ev);

			}

		}

		xmlObj.onreadystatechange=rc;

		if(pmp) xmlObj.send(pc); else xmlObj.send("");

		if(pa==false) rc();

		return true;

	}

	this.setcharset=function(cs) { encode=$GEC(cs); }

	this.get=function() {

		var p=[],av=arguments;

		$GP(p,av,[this.url,this.oncomplete],[null,$CB]);

		if(!p[0]&&!p[1]) return false;

		return(send(p[0],"",p[1],"GET",this.async));

	}

	this.update=function() {

		var p=[],purl,puo,pinv,pcnt,av=arguments;

		$GP(p,av,[this.oncomplete,this.url,-1,-1],[$CB,null,$N,$N]);

		if(p[2]==-1) p[3]=1;

		var sf=function(){send(p[1],"",p[0],"GET",AJAX.async);};

		var id=$GID();

		var cf=function(cc) {

			sf(); cc--; if(cc==0) return;

			$SOP(id,setTimeout(function(){cf(cc);},p[2]));

		}

		cf(p[3]);

		return id;

	}

	this.stopupdate=function(id) {

		clearTimeout($LOP(id));

	}

	this.post=function() {

		var p=[],av=arguments;

		$GP(p,av,[this.url,this.content,this.oncomplete],[null,null,$CB]);

		if(!p[0]&&!p[2]) return false;

		return(send(p[0],p[1],p[2],"POST",this.async));

	}

	this.postf=function() {

		var p=[],fo,vaf,pcbf,purl,pc,pm,ac=arguments.length,av=arguments;

		fo=ac>0?$VO(av[0]):false;

		if(!fo||(fo&&fo.nodeName!="FORM")) return false;

		vaf=fo.getAttribute("onvalidate");

		vaf=vaf?(typeof(vaf)=="string"?new Function(vaf):vaf):null;

		if(vaf&&!vaf()) return false;

		$GP(p,[av[1],fo.getAttribute("action"),fo.getAttribute("method")],[this.oncomplete,this.url,this.method],[$CB,null,null]);

		pcbf=p[0];purl=p[1];

		if(!pcbf&&!purl) return false;

		pc=this.formToStr(fo); if(!pc) return false;

		if(p[2].toUpperCase()=="POST")

			return(send(purl,pc,pcbf,"POST",true));

		else {

			purl+=(purl.indexOf("?")>-1?"&":"?")+pc;

			return(send(purl,"",pcbf,"GET",true));

		}

	}

	this.formToStr=function(fc) {

		var i,qs="",and="",ev="";

		for(i=0;i<fc.length;i++) {

			e=fc[i];

			if (e.name!='') {

				if (e.type=='select-one'&&e.selectedIndex>-1) ev=e.options[e.selectedIndex].value;

				else if (e.type=='checkbox' || e.type=='radio') {

					if (e.checked==false) continue;

					ev=e.value;

				}

				else ev=e.value;

				ev=encode(ev); qs+=and+e.name+'='+ev; and="&";

			}

		}

		return qs;

	}

}