react-native取回状态代码+ json

Question

我在react-native中使用fetch进行API调用。

我需要获取状态码(200，401，404)和响应数据。

这项工作获得响应数据:

return fetch(url)
.then(response => {
  return response.json();
})
.then(res => {
  console.log("reponse :", res); // <-------- res is ok with data
 })    .catch(error => {
  console.error(error);
  return { name: "network error", description: "" };
});

现在我先调整第一个然后获取状态码，但数据不是我所需要的

return fetch(url)
.then(response => {
  const statusCode = response.status;
  const data = response.json();
  return { statusCode, data };
})
.then(res => {
  console.log("reponse :", res); // <-------- i get a "promise"
 }).catch(error => {
  console.error(error);
  return { name: "network error", description: "" };
});

控制台日志:

  {statusCode: 200, data: Promise}

Answer 1

response.json()返回一个promise，您应该等待直到实现它。为此，您可以将Promise.all与两个元素组成的数组一起使用:statusCode和response.json()调用:

return fetch(url)
  .then(response => {
    const statusCode = response.status;
    const data = response.json();
    return Promise.all([statusCode, data]);
  })
  .then([res, data] => {
    console.log(res, data);
  })
  .catch(error => {
    console.error(error);
    return { name: "network error", description: "" };
  });

//编辑
您可以创建一个处理响应的函数

function processResponse(response) {
  const statusCode = response.status;
  const data = response.json();
  return Promise.all([statusCode, data]).then(res => ({
    statusCode: res[0],
    data: res[1]
  }));
}

并使用then()

 return fetch(url)
    .then(processResponse)
    .then(res => {
        const { statusCode, data } = res;
        console.log("statusCode",statusCode);
        console.log("data",data);
    }) .catch(error => {
    console.error(error);
    return { name: "network error", description: "" };
  });