react-native fetch返回状态码+ json

Question

我在react-native中使用fetch来进行API调用.

我需要获取状态代码(200,401,404)和响应数据.

这项工作来获取响应数据:

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: "" };
});

现在我调整第一个然后获取状态代码但数据不是我除了

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()返回一个承诺,你应该等到它完成.要做到这一点,你可以使用Promise.all两个元素的数组:statusCode并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: "" };
  });

//编辑你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: "" };
  });