redux-saga-api yield调用有效，但没有返回任何数据

Question

我现在正尝试使用redux saga和fetch进行POST。我使用创造性蒂姆的材料工具包作为默认模板。

您想要通过yield调用执行的API实际上是与服务器通信的(服务器将接收到的值存储在DB中(，但响应是UNDEFINED。

当我在另一个项目中尝试与redux传奇相关的代码时，它运行良好，但仅在带有模板的项目中运行。但我不认为这是模板的问题。当我尝试与另一台服务器通信时，也出现了同样的问题。(在使用axios的GET通信中也有一个错误，但这只在提取时有效。(

我的模块如下所示，

import { createAction, handleActions } from 'redux-actions';
import createRequestSaga, {
createRequestActionTypes
} from '../lib/createRequestSaga';
import * as askAPI from '../lib/api/ask';
import { takeLatest } from 'redux-saga/effects';
const INITIALIZE = 'ask/INITIALIZE';
const CHANGE_FIELD = 'ask/CHANGE_FIELD';
const [
WRITE_ASK,
WRITE_ASK_SUCCESS,
WRITE_ASK_FAILURE
] = createRequestActionTypes('ask/WRITE_ASK');
export const initialize = createAction(INITIALIZE);
export const changeField = createAction(CHANGE_FIELD, ({ key, value }) => ({
key,
value
}));
export const writeAsk = createAction(WRITE_ASK, ({ name, email, body }) => ({
name,
email,
body
}));
const writeAskSaga = createRequestSaga(WRITE_ASK, askAPI.writeAsk);
export function* writeSaga() {
yield takeLatest(WRITE_ASK, writeAskSaga);
}
const initialState = {
name: '',
email: '',
body: '',
ask: null,
askError: null
};
const ask = handleActions(
{
[INITIALIZE]: state => initialState,
[CHANGE_FIELD]: (state, { payload: { key, value } }) => ({
...state,
[key]: value
}),
[WRITE_ASK]: state => ({
...state,
ask: null,
askError: null
}),
[WRITE_ASK_SUCCESS]: (state, { payload: ask }) => ({
...state,
ask
}),
[WRITE_ASK_FAILURE]: (state, { payload: askError }) => ({
...state,
askError
})
},
initialState
);
export default ask;

createRequestSaga如下所示。createRequestSaga.js

import { call, put, fork, delay } from 'redux-saga/effects';
import { startLoading, finishLoading } from '../modules/loading';
export const createRequestActionTypes = type => {
const SUCCESS = `${type}_SUCCESS`;
const FAILURE = `${type}_FAILURE`;
return [type, SUCCESS, FAILURE];
};
export default function createRequestSaga(type, request) {
const SUCCESS = `${type}_SUCCESS`;
const FAILURE = `${type}_FAILURE`;
return function*(action) {
yield put(startLoading(type)); //LOADING START
try {
const response = yield call(request, action.payload);
console.log(response); //THIS IS UNDEFINED
yield put({
type: SUCCESS,
payload: response.data
});
} catch (e) {
console.log(e); 
yield put({
type: FAILURE,
payload: e,
error: true
});
}
yield put(finishLoading(type)); //LOADING FINISH
};
}

这是api代码

export const writeAsk = ({ name, email, body }) => {
fetch('http://allnewfit.net:4000/api/ask', {
method: 'POST',
body: JSON.stringify({ name, email, body }),
headers: {
'Content-Type': 'application/json'
}
});
};

我希望响应的输出如下，(只是服务器的响应(

{
"fieldCount": 0,
"affectedRows": 1,
"insertId": 38,
"info": "",
"serverStatus": 2,
"warningStatus": 0
}

但实际输出是未定义的

代码中的问题在哪里？谢谢你的帮助。

Answer 1

您需要通过使用return或删除fetch周围的花括号来返回fetch生成的promise：

export const writeAsk = ({ name, email, body }) =>
fetch('http://allnewfit.net:4000/api/ask', {
method: 'POST',
body: JSON.stringify({ name, email, body }),
headers: {
'Content-Type': 'application/json'
}
});