[英]Redux-thunk with promise does not work
我正在尝试与redux-thunk链接调度。 我有2个动作创建者,如下所示:
getResourceLinks :
export const getResourceLinks = () => {
return dispatch => {
let req = {
url: getRootUrl(),
header: {
Accept: 'application/json'
}
};
return request(req).then(res => {
dispatch({
type: ActionTypes.RESOURCE.LOAD_URL_SUCCESS,
payload: res.body
});
}).catch(err => {
dispatch({
type: ActionTypes.RESOURCE.LOAD_URL_ERROR,
payload: err
});
});
}
};
和loadAppliances :
export const loadAppliances = () => {
return (dispatch, getState) => {
return dispatch(getResourceLinks()).then(res => {
const {resources} = getState();
let req = {
url: getResourceLink(Resources.Appliances, res.body),
header: {
Accept: 'application/json'
}
};
request(req).then(res1 => {
dispatch({
type: ActionTypes.APPLIANCE.LOAD_SUCCESS,
payload: res1.body
});
}).catch(err => {
dispatch({
type: ActionTypes.APPLIANCE.LOAD_ERROR,
payload: err
});
});
});
};
};
我遇到一个错误: Uncaught TypeError: Cannot read property 'then' of undefined
loadAppliances操作中第3行Uncaught TypeError: Cannot read property 'then' of undefined
。 Promise已正确返回,不是吗? 我做错什么了吗? 我已经仔细查看了thunk-redux的示例,但是我仍然找不到错误的地方。
更新 。 这是要求:
import superagent from 'superagent';
import superagentPromisePlugin from 'superagent-promise-plugin';
import {RequestMethods} from '../constant';
const request = ({url, method = RequestMethods.GET, param, body, header}) => {
let methodStr;
switch (method) {
case RequestMethods.POST:
methodStr = 'POST';
break;
case RequestMethods.PUT:
methodStr = 'PUT';
break;
case RequestMethods.DELETE:
methodStr = 'DELETE';
break;
default:
methodStr = 'GET';
break;
}
let req = superagent(methodStr, url).use(superagentPromisePlugin);
//set header
if (header) {
req.set(header)
}
//set param
if (param) {
req.query(param)
}
//set body
if (body) {
req.send(body)
}
return req;
};
export default request;
这里的问题是dispatch
不会返回您的承诺。 它实际上返回调度的动作本身。 ( 参考 )。
return dispatch(getResourceLinks()).then(res => {
^--- this is the problem
我将采用的方法是在您的第一个成功调用之后调度一个动作,并在状态中存储所有相关信息,然后调度下一个调用并存储其响应。
const getResourceLinks = () => {
return request({
url: getRootUrl(),
header: {
Accept: 'application/json'
}
});
};
const getAppliances = (appliances) => {
return request({
url: getResourceLink(Resources.Appliances, appliances),
header: {
Accept: 'application/json'
}
})
};
export const loadAppliances = () => {
return (dispatch, getState) => {
getResourceLinks()
.then(res => {
dispatch({
type: ActionTypes.RESOURCE.LOAD_URL_SUCCESS,
payload: res.body
});
return getAppliances(res.body)
.then(res1 => {
dispatch({
type: ActionTypes.APPLIANCE.LOAD_SUCCESS,
payload: res1.body
});
})
.catch(err => {
dispatch({
type: ActionTypes.APPLIANCE.LOAD_ERROR,
payload: err
});
});
})
.catch(err => {
dispatch({
type: ActionTypes.RESOURCE.LOAD_URL_ERROR,
payload: err
});
});
}
}
您可能还想看看redux-saga
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