我在react redux中尝试了一些应用程序,我在更新(推送,删除,更新)状态的嵌套数组时遇到问题。
我有一个像这样的服务对象:
{
name: 'xzy',
properties: [
{ id: 1, sName: 'xxx'},
{ id: 2, sName: 'zzz'},
]
}
无论我在减少器中使用属性集合做了什么(在向集合添加属性的情况下)都会产生问题,即所有属性都与我最近添加的最后一个属性具有相同的值 - >添加的属性对象位于服务属性集合中,但该操作将替换此集合中所有属性中的所有值。 我的减速机:
export function service(state = {}, action) {
switch (action.type) {
case 'ADD_NEW_PROPERTY':
console.log(action.property) // correct new property
const service = {
...state, properties: [
...state.properties, action.property
]
}
console.log(service); // new property is pushed in collection but all properties get same values
return service
default:
return state;
}
}
我尝试了一些使用immutability-helper库的解决方案,它会产生同样的问题:
export function service(state = {}, action) {
case 'ADD_NEW_PROPERTY':
return update(state, {properties: {$push: [action.property]}})
default:
return state;
}
例如,当我向上面的示例添加新属性{ id: 1, sName: 'NEW'}
时,我将获得此状态:
{
name: 'xzy',
properties: [
{ id: 1, sName: 'NEW'},
{ id: 1, sName: 'NEW'},
{ id: 1, sName: 'NEW'}
]
}
有人可以帮忙吗? :)
答案 0 :(得分:1)
同时复制export function service(state = {}, action) {
switch (action.type) {
case 'ADD_NEW_PROPERTY':
console.log(action.property) // correct new property
const service = {
...state,
properties: [
...state.properties,
{ ...action.property }
]
}
console.log(service); // new property is pushed in collection but all properties get same values
return service
default:
return state;
}
}
。无论调度此动作是什么,它都可以重用相同的对象。
node-gyp
答案 1 :(得分:1)
我建议您使用不可变数据https://facebook.github.io/immutable-js/docs/#/List
import { fromJS, List } from 'immutable';
const initialState = fromJS({
propeties: List([{ id: 1, sName: 'xyz' }]
}
function reducer(state = initialState, action) {
case ADD_NEW_PROPERTY:
return state
.update('properties', list => list.push(action.property));
// ...
}
答案 2 :(得分:0)
您的服务缩减器应该看起来像这样:
// Copy the state, because we're not allowed to overwrite the original argument
const service = { ...state };
service.properties.append(action.property)
return service
答案 3 :(得分:0)
您应该在返回之前复制状态。
export default function(state = {}, action) {
switch(action.type) {
case 'GET_DATA_RECEIVE_COMPLETE': {
const data = action.firebaseData;
const newState = Object.assign({}, state, {
data
});
return newState
}
default:
return state;
}
}