我一直在与这个争斗太久,有人能指出我正确的方向吗? 问题:当我创建一个列表时,我能够更新/删除它。我也可以添加项目并更新/删除这些项目。当我添加另一个列表时,前者的项目被转移到后者,然后我无法编辑项目。如果我删除列表并且不刷新浏览器,则项目仍在列表中。我需要一种方法将两者结合在一起,使列表只知道其项目 在此先感谢您的帮助。
/actions/lists.js
export const CREATE_LIST = 'CREATE_LIST'
export function createList(list) {
return {
type: CREATE_LIST,
id: uuid.v4(),
items: list.items || [],
...list
}
}
export const CONNECT_TO_LIST = 'CONNECT_TO_LIST'
export function connectToList(listId, itemId) {
return {
type: CONNECT_TO_LIST,
listId,
itemId
}
}
export const DISCONNECT_FROM_LIST = 'DISCONNECT_FROM_LIST'
export function disconnectFromList(listId, itemId) {
return {
type: DISCONNECT_FROM_LIST,
listId,
itemId
}
}
/actions/items.js
export const CREATE_ITEM = 'CREATE_ITEM'
export function createItem(item) {
return {
type: CREATE_ITEM,
item: {
id: uuid.v4(),
...item
}
}
}
export const UPDATE_ITEM = 'UPDATE_ITEM'
export function updateItem(updatedItem) {
return {
type: UPDATE_ITEM,
...updatedItem
}
}
/reducers/lists.js
import * as types from '../actions/lists'
const initialState = []
export default function lists(state = initialState, action) {
switch (action.type) {
case types.CREATE_LIST:
return [
...state,
{
id: action.id,
title: action.title,
items: action.items || []
}
]
case types.UPDATE_LIST:
return state.map((list) => {
if(list.id === action.id) {
return Object.assign({}, list, action)
}
return list
})
case types.CONNECT_TO_LIST:
const listId = action.listId
const itemId = action.itemId
return state.map((list) => {
const index = list.items.indexOf(itemId)
if(index >= 0) {
return Object.assign({}, list, {
items: list.items.length > 1 ? list.items.slice(0, index).concat(
list.items.slice(index + 1)): []
})
}
if(list.id === listId) {
return Object.assign({}, list, {
items: [...list.items, itemId]
})
}
return list
})
case types.DISCONNECT_FROM_LIST:
return state.map((list) => {
if(list.id === action.listId) {
return Object.assign({}, list, {
items: list.items.filter((id) => id !== action.itemId)
})
}
return list
})
default:
return state
}
}
/reducers/items.js
import * as types from '../actions/items'
const initialState = []
export default function items(state = initialState, action) {
switch (action.type) {
case types.CREATE_ITEM:
return [ ...state, action.item ]
case types.UPDATE_ITEM:
return state.map((item) => {
if(item.id === action.id) {
return Object.assign({}, item, action)
}
return item
})
case types.DELETE_ITEM:
return state.filter((item) => item.id !== action.id )
default:
return state
}
}
/components/List.jsx
import React from 'react'
import { connect } from 'react-redux'
import { bindActionCreators } from 'redux'
import Items from './Items'
import Editor from './Editor'
import * as listActionCreators from '../actions/lists'
import * as itemActionCreators from '../actions/items'
export default class List extends React.Component {
render() {
const { list, updateList, ...props } = this.props
const listId = list.id
return (
<div {...props}>
<div className="list-header"
onClick={() => props.listActions.updateList({id: listId, isEditing: true})}
>
<div className="list-add-item">
<button onClick={this.addItem.bind(this, listId)}>+</button>
</div>
<Editor
className="list-title"
isEditing={list.isEditing}
value={list.title}
onEdit={title => props.listActions.updateList({id: listId, title, isEditing: false})}
/>
<div className="list-delete">
<button onClick={this.deleteList.bind(this, listId)}>x</button>
</div>
</div>
<Items
items={this.listItems}
onValueClick={id => props.itemActions.updateItem({id, isEditing: true})}
onEdit={(id, text) => props.itemActions.updateItem({id, text, isEditing: false})}
onDelete={itemId => this.deleteItem(listId, itemId)}
/>
</div>
)
}
listItems() {
props.list.items.map(id => state.items[
state.items.findIndex(item => item.id === id)
]).filter(item => item)
}
deleteList(listId, e) {
e.stopPropagation()
this.props.listActions.deleteList(listId)
}
addItem(listId, event) {
event.stopPropagation()
const item = this.props.itemActions.createItem({
text: 'New Shopping Item'
})
this.props.listActions.connectToList(listId, item.id)
}
deleteItem(listId, itemId) {
this.props.listActions.disconnectFromList(listId, itemId)
this.props.itemActions.deleteItem(itemId)
}
}
function mapStateToProps(state) {
return {
lists: state.lists,
items: state.items
}
}
function mapDispatchToProps(dispatch) {
return {
listActions: bindActionCreators(listActionCreators, dispatch),
itemActions: bindActionCreators(itemActionCreators, dispatch)
}
}
export default connect(mapStateToProps, mapDispatchToProps)(List)
/components/List.jsx
import React from 'react'
import List from './List.jsx'
export default ({lists}) => {
return (
<div className="lists">{lists.map((list) =>
<List className="list" key={list.id} list={list} id={list.id} />
)}</div>
)
}
/components/Items.jsx
import React from 'react'
import { connect } from 'react-redux'
import Editor from './Editor'
import Item from './Item'
export default class Items extends React.Component {
render () {
const {items, onEdit, onDelete, onValueClick, isEditing} = this.props
return (
<ul className="items">{items.map(item =>
<Item
className="item"
key={item.id}
id={item.id}
isEditing={item.isEditing}>
<Editor
isEditing={item.isEditing}
value={item.text}
onValueClick={onValueClick.bind(null, item.id)}
onEdit={onEdit.bind(null, item.id)}
onDelete={onDelete.bind(null, item.id)}
/>
</Item>
)}</ul>
)
}
}
export default connect(
state => ({
items: state.items
})
)(Items)
/components/Item.jsx
import React from 'react'
export default class Item extends React.Component {
render() {
const { id, isEditing, ...props } = this.props
return (
<li {...props}>{props.children}</li>
)
}
}
/components/App.jsx
class App extends React.Component {
handleClick = () => {
this.props.dispatch(createList({title: "New Shopping List"}))
}
render() {
const lists = this.props.lists
return (
<div>
<button
className="add-list"
onClick={this.handleClick}>Add Shopping List</button>
<Lists lists={lists}/>
</div>
)
}
}
export default connect(state => ({ lists: state.lists }))(App)
答案 0 :(得分:1)
假设这一切都意味着一次只能在一个阵列上运行,这部分看起来很可疑:
case types.CREATE_LIST:
return [
...state,
{
id: action.id,
title: action.title,
items: action.items || []
}
]
...state
正在扩展您正在返回的新数组中的现有数组,并且听起来不像您实际需要的行为。我的第一个猜测是,当你创建一个新列表时,可能想要只返回一个新项目,而不是整个旧列表内容加上那个新项目。
您的其他一些不可变样式的更新代码看起来也很复杂。我知道“更新数组中间的东西”并不总是很容易处理。您可能需要查看this SO post on updating immutable data,其中列出了几种方法。我还有一个链接仓库,用于编目与Redux相关的库,它有一个immutable data management libraries列表,可以让您更轻松。
答案 1 :(得分:0)
虽然@markerikson的提示是我所遇到的问题的一部分,但它并没有完全解决。我必须将mapStateToProps
修复为此
function mapStateToProps(state, props) {
return {
lists: state.lists,
listItems: props.list.items.map(id => state.items[
state.items.findIndex(item => item.id === id)
]).filter(item => item)
}
}
并删除我Items.jsx