React中fetch请求的封装方法

对于GET请求则将参数封装到options下的params，即可添加进入url。

/**
 * Requests a URL, returning a promise.
 *
 * @param  {string} url       The URL we want to request
 * @param  {object} [options] The options we want to pass to "fetch"
 * @return {object}           An object containing either "data" or "err"
 */
export default function request(url, options) {
  const defaultOptions = {
    credentials: 'include',
  };
  const newOptions = { ...defaultOptions, ...options };
  if (newOptions.method === 'POST' || newOptions.method === 'PUT') {
    newOptions.headers = {
      Accept: 'application/json',
      'Content-Type': 'application/json; charset=utf-8',
      ...newOptions.headers,
    };
    newOptions.body = JSON.stringify(newOptions.body);
  }
  var str = ''
  if (newOptions.method === 'GET' && newOptions.params) {
    str += '?';
			Object.keys(newOptions.params).forEach(function(val){
				str += val + '=' + encodeURIComponent(newOptions.params[val]) + '&';
			})
  }

  return fetch(url + str, newOptions)
    .then(checkStatus)
    .then(response => response.json())
    .catch((error) => {
      if (error.code) {
        notification.error({
          message: error.name,
          description: error.message,
        });
      }
      if ('stack' in error && 'message' in error) {
        notification.error({
          message: `请求错误: ${url}`,
          description: error.message,
        });
      }
      return error;
    });
}