/**
* @author                skyzhw
* @filename                HttpRequest.class.js
* @function        javascript client ajax dealwith
* @datetime        2006-3-20
*/
/*        
* Function: Create a httpRequest object
*/ 
function HttpRequest(){
        this._httpRequest=null;                                                                        //HttpRequest request object
        this._callBack=null;                                                                        //Call back function
        this._domResult=true;                                                                        //Result if dom object or text string
        this._requestData=null;                                                                        //Request data
        this._requestResult=null;                                                                //HttpRequest result
        this._stateString=null;                                                                        //Current request state string
        this._error=false;                                                                                //Current if have error
        this._callBackPara=null;                                                                //Current callback function parama
        //internal method for get HttpRequestObject
        this.init=function(){
                //Judge if Not IE
                if(window.XMLHttpRequest){
                        this._httpRequest=new XMLHttpRequest();
                        //Set request mime is text/xml
                        if(this._httpRequest.overrideMimeType){
                                this._httpRequest.overrideMimeType('text/xml');
                        }
                }else if(window.ActiveXObject){
                        try{
                                this._httpRequest=new ActiveXObject("Msxml2.XMLHTTP");
                        }catch(ex){
                                try{
                                        this._httpRequest=new ActiveXObject("Microsoft.XMLHTTP");
                                }catch(ex){
                                        this._setMessage(ex,true);
                                        return;
                                }
                        }
                }
                //Judge HttpRequest object create successful
                if(!this._httpRequest){
                        this._setMessage("HttpRequest object create fail!Please try again......",true);
                        return;
                }        
        }
        /*        
         * Function: Set the request header
         * namePar:request's header name
         * valuePar:request's header value
         */
        this.doSetRequestHeader=function(namePar,valuePar){
                if(this._error){
                        return;
                }
                this._httpRequest.setRequestHeader(namePar,valuePar);
        }
        /*        
         * Function: Set the request data
         * dataPar:request's send data;
         */
        this.doSetRequestData=function(dataPar){
                if(this._error){
                        return;
                }
                this._requestData=dataPar;
        }
        /*
         *Function get RequestHttp Object
        */
        this._getRequestObj=function(){
                if(this._error){
                        return;
                }
                return this._httpRequest;
        }
        /*
         * Function:Set Callback function para
         */
        this.doSetCallBack=function(callBack,paraData){
                this._callBack=(callBack)?callBack:null;
                this._callBackPara=(paraData)?paraData:null;
        };
        /*
         * Function: Get current stateString
         */
        this.doGetState=function(){
                return this._stateString;
         }
         /*
         * Function: get current Error 
         */
        this.doGetError=function(){
                return this._error;
         }
         /*
          *
          */
    this.doCallBack=function(){
                this._callBack(this._requestResult,this._callBackPara);
        }

        /*        
         * Function: Send the request
         * urlPar: request's url path
         * [methodPar]:request's method
         * [domPar]: request's result is dom or string
         */
        this.doSendResuest=function(urlPar,methodPar,obj,domPar,asyPar){
                if(obj._error){
                        return;
                }
                methodPar=((methodPar)?methodPar:"GET");
                asyPar=((asyPar)?asyPar:true);
                this._domResult=(domPar)?domPar:obj._domResult;
                try{
                                var a=this._getRequestObj();
                                a.onreadystatechange=function(){
                                        if(obj._error){
                                                return;
                                        }
                                        var readyStateTmp=a.readyState;
                                        if(readyStateTmp==0){
                                                obj._setMessage("No initialize");
                                        }else if(readyStateTmp==1){
                                                obj._setMessage("Reading......");
                                        }else if(readyStateTmp==2){
                                                obj._setMessage("Had read!");
                                        }else if(readyStateTmp==3){
                                                obj._setMessage("Turning each other...... ");
                                        }else if(readyStateTmp==4){
                                                var statusTmp=a.status;
                                                if(statusTmp==404){
                                                        obj._setMessage("Not found request file!",true);
                                                }else if(statusTmp==200){
                                                        obj._setMessage("Finished");        
                                                        if(this._domResult && window.XMLHttpRequest){
                                                                obj._requestResult=a.responseXml;
                                                        }else{
                                                                obj._requestResult=a.responseText;
                                                        }
                                                        if(obj._callBack){
                                                                obj.doCallBack();
                                                        }
                                                }else{
                                                        obj._setMessage("Unknow error!");
                                                }
                                        }else{
                                                obj._setMessage("Unknow error!");
                                        }        
                                }
                        a.open(methodPar,urlPar,asyPar);
                        a.send(obj._requestData);
                }catch(ex){
                        obj._setMessage(ex,true);
                }
        }
        /*
         * Function: Deal exception error 
         * exPar:error string
         */
        this._setMessage=function(exPar,mark){
                this._stateString=exPar.toString();
                this._error=(mark)?mark:false;
         }
}