原生js 实现 Ajax 跨浏览器使用

js 实现 Ajax 跨浏览器使用

var CommonUtils = {};

(function(CommonUtils){
    //---- Ajax module ----
    CommonUtils.ajax = {};
    /**
        @description Create XMLHttpRequest
        @return XMLHttpRequest Instance
    */
    CommonUtils.ajax._createXHR =function createXmlHttpRequest(){
        var xmlHttp ;
        if(window.XMLHttpRequest){
            xmlHttp = new XMLHttpRequest();
        }
        else if(window.ActiveXObject){
            var versions = [
                'Microsoft.XMLHTTP',
                'MSXML.XMLHTTP',
                'Msxml2.XMLHTTP.7.0',
                'Msxml2.XMLHTTP.6.0',
                'Msxml2.XMLHTTP.5.0',
                'Msxml2.XMLHTTP.4.0',
                'MSXML2.XMLHTTP.3.0',
                'MSXML2.XMLHTTP'
            ];
            //try to create xhr
            for(var i=0; i<versions.length; i++){
                try{
                    xmlHttp = new ActiveXObject(versions[i]);
                    if(xmlHttp){
                       return xmlHttp;
                   }
                }catch(e){
                    xmlHttp = false;
                }
            }
        }
        return xmlHttp;
    }
    /**
     * @description Ajax request
     * @param
     *      options{method,url,success,failure,params}
            scope
    */
    CommonUtils.ajax.request = function(options,scope){
        if(!options.method||!options.success||!options.failure){
            console.log('Parameters is not correct');
            return false;
        }

        var method = options.method.toUpperCase(),
            url = options.url,
            successFn = options.success,
            failureFn = options.failure,
            params = options.params,
            callFn = null,
            jsonData = null;
        var xhr = CommonUtils.ajax._createXHR();

        if(!xhr){
            console.log("Create xhr failed");
            return false;
        }
        if("GET" == method && params){
            for(var property in params){
                var p = property + '=' + params[property];
                url = url + ((url.indexOf('?') >-1)?'&':'?') + p;
            }
        }else if("POST" == method && params){
            jsonData = JSON.stringify(params);
        }

        xhr.open(method,url,true);
        xhr.onreadystatechange=function(){
            if (xhr.readyState == 4) {
                var status = xhr.status;

                if (status >= 200 && status < 300) {
                    callFn = successFn;
                } else {
                    callFn = failureFn;
                }
                if(scope){
                    callFn.call(scope?scope:this,status,xhr.responseText,xhr.responseXML);
                }
            };
        }

        if('POST' == method){
            xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        }

        xhr.send(jsonData);
    }

}(CommonUtils));