fetch

/*

• developer.mozilla.org/zh-CN/docs/… */

//fetch：只要服务器有返回结果，就是成功

// 设置公共的请求前缀

// const env = process.env.NODE_ENV;
let env = 'development',
    baseURL = "";
switch (env) {
    case 'development':
        baseURL = "http://127.0.0.1:8888";
        break;
    case 'test':
        baseURL = "http://168.23.12.124:8888";
        break;
    case 'production':
        baseURL = "http://api.zhufengpeixun.cn";
        break;
}

  /*
   * method
   * params
   * body
   * headers 
   * responseType:'text/json/blob/buffer'
   */
  function request(url, config) {
      config = config || {};
      let {
          params,
          headers: headers_config,
          body,
          method = 'GET',
          responseType = 'json'
      } = config;

      // 处理URL
      if (url.substr(0, 4).toLowerCase() !== "http") {
          // 传递的URL不设置前缀，我们自己把公共前缀加上
          url = baseURL + url;
      }

      // 处理HEADERS
      let headers = {
          'Content-Type': 'application/x-www-form-urlencoded'
      };
      if (headers_config) {
          headers = Object.assign(headers, headers_config);
      }

      // 处理PARAMS「依赖QS库」
      if (params) {
          url += `${url.includes('?')?'&':'?'}${Qs.stringify(params)}`;
      }

      // 处理BODY「支持对象格式」
      if (body !== null && typeof body === "object") {
          const ContentType = headers['Content-Type'];
          if (ContentType === "application/x-www-form-urlencoded") {
              body = Qs.stringify(body);
          }
          if (ContentType === "application/json") {
              body = JSON.stringify(body);
          }
      }

      // 发送请求
      config = {
          method,
          headers,
          credentials: 'include',
          cache: 'no-cache',
      };
      if (/^(POST|PUT|PATCH)$/i.test(method)) {
          config.body = body;
      }
      return fetch(url, config).then(response => {
          let status = response.status,
              result = '';
          if (status >= 200 && status < 300) {
              // 处理返回的结果
              switch (responseType) {
                  case 'json':
                      result = response.json();
                      break;
                  case 'text':
                      result = response.text();
                      break;
                  case 'blob':
                      result = response.blob();
                      break;
                  case 'buffer':
                      result = response.arrayBuffer();
                      break;
              }
              return result;
          }
          return Promise.reject({
              status: response.status,
              statusText: response.statusText
          });
      }).catch(reason => {
          let status = reason.status;
          if (status) {
              // 状态码错误
          } else {
              // 断网了
          }
          return Promise.reject(reason);
      });
  }

  request('/user/login', {
      method: 'POST',
      body: {
          account: '18310612838',
          password: md5('1234567890')
      }
  }).then(data => {
      console.log(data);
      return request('/user/login');
  }).then(data => {
      console.log(data);
  });






  /* let fmd = new FormData;
  fetch('http://127.0.0.1:8888/user/login', {
      headers: {
          // 设置请求头
      },
      method: 'POST',
      credentials: 'include',
      cache: 'no-cache',
      // 设置请求主体 只对POST系列有用（不是POST请求不要设置）
      // body: fmd
  }).then(response => {
      let status = response.status;
      if (status >= 200 && status < 300) {
          // response是Response类的实例
          //   + response.json()
          //   + response.text()
          //   + response.blob()  //二进制形式
          //   + response.arrayBuffer() 
          // 返回的都是Promise实例
          let data = response.json();
          return data;
      }
      return Promise.reject({
          status: response.status,
          statusText: response.statusText
      });
  }).then(data => {
      console.log(data);
  }).catch(reason => {
      let status = reason.status;
      if (status) {
          // 状态码错误
      } else {
          // 断网了
      }
  }); */