Reactjs redux reducer中更新状态的问题
我已采取下列行动:Reactjs redux reducer中更新状态的问题,reactjs,redux,react-redux,Reactjs,Redux,React Redux,我已采取下列行动: export function fetchUsersForTeam() { return { type: 'FETCH_USERS_FOR_TEAM__RESOLVED', teamId: 123, responseData: [ { userId: 1, name: 'Alice' }, { userId: 2, name: 'Bob' }, {
export function fetchUsersForTeam() {
return {
type: 'FETCH_USERS_FOR_TEAM__RESOLVED',
teamId: 123,
responseData: [
{ userId: 1, name: 'Alice' },
{ userId: 2, name: 'Bob' },
{ userId: 3, name: 'Chris' }, // This is new! "Christopher" is now "Chris"
],
};
};
这是我的减速机:
import _ from 'lodash';
function getUserById(users, id) {
return _.find(users, {userId: id});
}
const userServiceReducer = (state, action) => {
if (action.type === 'FETCH_USERS_FOR_TEAM__RESOLVED') {
const userIds = state.usersForTeams[action.teamId];
const data = action.userData;
const result = userIds.map(idx => ({
...getUserById(state.userData, idx),
userData: getUserById(action.responseData, idx),
}));
console.log(result);
return result;
}
return state;
};
export default userServiceReducer;
以下是初始状态:
const initState = {
userData: {
1: { userId: 1, name: 'Alice' },
3: { userId: 3, name: 'Christopher' },
4: { userId: 4, name: 'Dave' },
5: { userId: 5, name: 'Eliza' },
},
usersForTeams: {
123: [1, 3],
456: [3, 4, 5],
},
};
减速器完成其“操作”后的新状态应如下所示:
const newState = {
userData: {
1: { userId: 1, name: 'Alice' },
3: { userId: 3, name: 'Chris' },
4: { userId: 4, name: 'Dave' },
5: { userId: 5, name: 'Eliza' },
},
usersForTeams: {
123: [1, 3],
456: [3, 4, 5],
},
};
每次reducer运行时,返回的结果都是一个对象数组,其中每个id都与usersForTeams
中匹配的键中的userId
相匹配
在上面的示例中,我的输出是:
[{ userId: 1, name: 'Alice' },
{ userId: 3, name: 'Christopher' },]
您的错误是没有将新用户数据合并到旧状态。 试试这样的
function getUserById(users, id) {
return _.find(users, user => user.userId === id);
}
const userServiceReducer = (state, action) => {
if (action.type === 'FETCH_USERS_FOR_TEAM__RESOLVED') {
const userIds = state.usersForTeams[action.teamId];
const data = action.userData;
const newUserData = userIds.map(idx => ({
...getUserById(state.userData, idx),
userData: getUserById(action.responseData, idx),
}));
return _.merge({}, state, {userData: newUserData});
}
return state;
};
啊,行了!我现在遇到的一个问题是,操作中的任何新值都没有应用于任何用户对象。例如克里斯托弗改成Chris@dennismonsewiczlodash的find函数receive predicate函数作为第二个参数(ref:),您应该像这样更改find的使用方式。查找(users,user=>user.userId==id);