简单的基于promise的ajax封装

  1 //调用方式:
  2 /*
  3   ajaxPrmomise({
  4   url:,
  5   method:,
  6   headers:{}
  7 }).then(res=>{})
  8 */
  9 
 10 ;(function(window){
 11   //设置默认的参数配置项
 12   let _default = {
 13     url:‘‘,
 14     baseURL:‘‘,
 15     method:‘GET‘,
 16     params:null, //get请求基于问号传参方式传递给服务器的内容
 17     headers:{},
 18     timeout:500,
 19     dataType:‘json‘, 
 20     data:null,  //post请求基于请求主体传参方式传递给服务器的内容
 21     cache:true   //是否缓存数据
 22   };
 23   //resolve,reject,response,fn
 24   let _setResponseMsg = function _setResponseMsg(...rest){
 25       let [
 26         resolve,
 27         reject,
 28         xhr,
 29         fn
 30       ] = rest,
 31       res = null,
 32       response = xhr;
 33       res.data = fn(response.responseText);
 34       res.status = response.status;
 35       res.statusText = response.statusText;
 36       res.xhr = response;
 37       res.headers = response.getAllResponseHeaders();
 38       resolve(res)
 39   }
 40 
 41   let _convertJSON = function _convertJSON(result){
 42       let data = "";
 43       try {
 44         data = JSON.parse(result);
 45       } catch (e) {
 46         reject(e)
 47       }
 48       return data
 49   }
 50 
 51   let _convertString = function _convertString(result){
 52       return result;
 53   }
 54 
 55   let _array_to_str = function _array_to_str(key,arr){
 56       let params = "";
 57       for(let i0;i<arr.length;i++){
 58         params += `${key}=${arr[i]}&`;
 59       }
 60       return params.slice(0,-1)
 61   }
 62 
 63   let _convertParams = function _convertParams(cache,params){
 64     let str = "?",
 65         time_str = cache ? "":(+(new Date())+"");
 66       if(typeof params == ‘object‘ && Object.keys(params).length > 0){
 67           for(let key in params){
 68             if(typeof params[key] == ‘object‘ && (length in params[key])){
 69               str += _array_to_str(key,params[key])
 70             }
 71             str += `${key}=${params[key]}`;
 72           }
 73       }
 74       return str+"&time="+time_str;
 75   }
 76 
 77   let _setHeader = function _setHeader(...res){
 78     let [xhr,headers] = res;
 79     for(let key in headers){
 80       xhr.setRequestHeader(key,headers[key])
 81     }
 82   }
 83 
 84   //基于promise管理ajax请求
 85   let ajaxPrmomise = function ajaxPrmomise(options={}){
 86       // 这里传递的options包含默认配置信息和用户基于暴露的_default修改后的信息
 87       for(let key in _default){
 88         if(key in options){
 89             options[key] = _default[key]
 90         }
 91       }
 92       let {
 93         url,
 94         method,
 95         baseURL,
 96         data,
 97         dataType,
 98         headers,
 99         cache,
100         params
101       } = options;
102       let xhr,send_data;
103 
104       return new Promise((resolve,reject)=>{
105           xhr = new XMLHttpRequest();
106           _setHeader(xhr,headers);
107           send_data = method.toLowerCase() == ‘get‘ ? _convertParams(cache,params):(method.toLowerCase() == ‘post‘? data:"");
108           all_url = baseURL + url + send_data;
109           xhr.open(method,all_url);
110           xhr.onreadystatechange = function(){
111             if(xhr.readyState == 4){
112               if(/^[23]\d{2}$/.test(xhr.status)){
113                   dataType = dataType.toUpperCase();
114                   if(dataType == "json")
115                     _setResponseMsg(resolve,reject,xhr,_convertJSON)
116                   _setResponseMsg(resolve,reject,xhr,_convertString)
117                 }
118               }
119             }
120             ajaxPrmomise.xhr = xhr;
121             xhr.send(send_data);
122           })
123       }
124   //修改默认配置，可以通过自己设置一些配置来覆盖默认配置
125   ajaxPrmomise.defaults = _default;
126 
127   ajaxPrmomise.get = function(url,options){
128       return ajaxPrmomise({
129         url:url,
130         method:‘get‘
131       })
132   };
133 
134   ajaxPrmomise.post = function(url,data,options){
135     return ajaxPrmomise({
136       url:url,
137       data:data,
138       method:‘post‘
139     })
140   }
141   window.ajaxPrmomise = ajaxPrmomise;
142 }(window))