我错过了asyn调用如何在react-redux中工作的关键步骤/概念。api调用后应用程序状态不会更新
目前,我能够做出api调用(也可以通过chrome-dev-tools查看返回的数据),但是响应数据并不是 ,反映在应用程序状态中;这意味着测验对象的状态(默认情况下是空对象)不会被更新。
我的期望是,当asyn调用解决时,我通过quizReducer中的响应进行解析,并返回一个反映响应数据的新状态(而不是突变状态)。
但是,每次进行调用时,更新的状态都会返回一个空的测验对象(这是初始状态)。
我知道我错过了一些东西,但我无法弄清楚什么;会真的很感激一些指针/解释。谢谢
的应用程序有看起来像这样的初始化状态/加载状态:
export default {
quizzes: [
{id: 0, name: "quiz_name2", completed: false, selected: false},
{id: 1, name: "quiz_name2", completed: false, selected: false}
],
quiz: { questions: {} }
};
设置有问题的减速机:
import initialState from './initialState';
import quizConstants from '../constants/quizConstants';
const actionTypes = quizConstants.actions
// when app loads, user has not selected any quiz therefore
// initialState is an empty object
// here action is the payload we get when a quiz is selected (see QUIZ_SELETED action creator)
export default function quiz(state=initialState.quiz, action) {
switch(action.type){
// when a quiz is selected, return new state
case actionTypes.SELECT_QUIZ:
return Object.assign(
{},
state,
{
id: action.quiz.id,
name: action.quiz.name,
completed: action.quiz.completed,
selected: !action.quiz.selected,
fetching: action.quiz.fetching,
fetched: action.quiz.fetched,
questions: action.quiz.questions
}
)
case actionTypes.REQUEST_QUIZ:
return Object.assign(
{},
state,
{
id: action.quiz.id,
name: action.quiz.name,
completed: action.quiz.completed,
selected: !action.quiz.selected,
fetching: !action.quiz.fetching,
fetched: action.quiz.fetched,
questions: action.quiz.questions
}
)
case actionTypes.RECEIVE_QUIZ:
return Object.assign(
{},
state,
{
id: action.quiz.id,
name: action.quiz.name,
completed: action.quiz.completed,
selected: !action.quiz.selected,
fetching: action.quiz.fetching,
fetched: !action.quiz.fetched,
quiz: action.quiz.questions
}
)
default:
return state
}
};
index.js(rootreducer):
import { combineReducers } from 'redux';
import { routerReducer } from 'react-router-redux';
import quizzes from './quizzesReducer'
import quiz from './quizReducer';
export default combineReducers({
quizzes,
quiz,
routing: routerReducer
});
QuizActionCreators
import quizConstants from '../constants/quizConstants';
import { quizzesEndPoint } from '../constants/appConstants';
import axios from 'axios';
const actionTypes = quizConstants.actions
// select a quiz
export const selectQuiz = (quiz) => {
return {
type: actionTypes.SELECT_QUIZ,
quiz
}
};
const receiveQuiz = (quiz, data) => {
return {
type: actionTypes.RECEIVE_QUIZ,
quiz,
data
}
};
// call when componentWillMount
export const fetchQuiz = (quiz) => {
console.log("Make an api request here")
const url = quizzesEndPoint.concat(quiz.name)
axios.get(url)
.then(response => response.data)
.then(data => receiveQuiz(quiz, data))
}
export default { selectQuiz, fetchQuiz};
你使用'redux-thunk'或'redux-saga'或类似的副作用库吗?此外,在QuizActionCreators文件中,倒数第三行给出'receiveQuiz'的调用。 'receiveQuiz'在哪里定义? – Mihir
hi @Mihir!我编辑的问题包括receiveQuiz(当问题最初发布时忘记包含它)。 – Uzzar
这是太多的代码才能通过。阅读如何发布[MCV](http://stackoverflow.com/help/mcve)问题。 –