yield 调用返回 undefined 而不是 resolved promise 值

Question

我是 Redux-Saga 的新手。下面是我的 api 调用的代码-

const registerUserRequest = (email, password, confirm_password, country_code, phone_number) =>
{
fetch(URLs.baseUrl + URLs.signUpUrl(email, password, confirm_password, country_code, phone_number), {
    method: 'POST',
    headers: {
        Accept: 'application/json',
        'Content-Type': 'application/json',
        'Cache-Control': 'no-cache, no-store, must-revalidate',
        'Pragma': 'no-cache',
        'Expires': 0
    },
})
}

function* registerUserToService(action)
{
try{
    const response = yield call(registerUserRequest, action.email, action.password, action.confirm_password, action.country_code, action.phone_number);
    const result = yield response.json();   
    if(result.error)
    {
        yield put({ type: REGISTER_USER_ERROR, error: result.error})
    }
    else
    {
        yield put({ type: REGISTER_USER_RESULT, result});
    } 
}
catch(e)
{
    console.log('registerUserException', e.message);
    yield put({ type: REGISTER_USER_ERROR, error: e.message})
}
};

但我得到的响应是未定义的，而不是已解决的承诺值，并且从响应中获取结果会产生异常 - 无法读取未定义的值 json。 如果能帮助理解这一点，我们将不胜感激。

Answer 1

您的函数 registerUserRequest 中没有 return 任何内容。如果你想得到承诺，returnfetch

const registerUserRequest = (email, password, confirm_password, country_code, phone_number) =>
{
return fetch(URLs.baseUrl + URLs.signUpUrl(email, password, confirm_password, country_code, phone_number), {
    method: 'POST',
    headers: {
        Accept: 'application/json',
        'Content-Type': 'application/json',
        'Cache-Control': 'no-cache, no-store, must-revalidate',
        'Pragma': 'no-cache',
        'Expires': 0
    },
})
}

Answer 2

获取不需要{}。移除围绕 fetch 的 {}。这样做吧。

const registerUserRequest = (email, password, confirm_password, country_code, phone_number) =>
fetch(URLs.baseUrl + URLs.signUpUrl(email, password, confirm_password, country_code, phone_number), {
    method: 'POST',
    headers: {
        Accept: 'application/json',
        'Content-Type': 'application/json',
        'Cache-Control': 'no-cache, no-store, must-revalidate',
        'Pragma': 'no-cache',
        'Expires': 0
    },
})

yield 调用返回 undefined 而不是 resolved promise 值

yield call returning undefined rather than resolved promise value

redux

redux-saga