我正在使用 React,遇到了嵌套列表的问题。我有 2 个列表 - 项目和待办事项,每个待办事项上都有一个 project_id
。我有 4 个与这些列表相关的组件:projects-component
呈现 project-component
列表,每个组件都有自己的 todos-component
将 projectId
属性设置为项目的 ID。 todos-component
使用 TodosWatchMixin
传递依赖于 component.props.projectId
的 getTodos
函数来获取todos 列表,然后呈现第 4 个组件的列表:todo-component
(此处未显示。)在我将新项目添加到列表中之前,一切都很好。该项目出现了,但待办事项发生了变化——新项目中包含另一个项目的待办事项,并且该项目的其余大部分待办事项似乎也发生了变化……交互(刷新或检查待办事项错误的项目)修复了它——所以我猜我在使用 React Chrome 开发工具时可以看到新项目有它自己的 ID,但它也有一个项目列表……我错过了什么?
下面是一些代码片段:
projects-component.js
/**
* @jsx React.DOM
*/
var React = require('react');
var Project = require('./project-component');
var ProjectsWatchMixin = require('./projects-watch-mixin');
var ProjectStore = require('./projects-store');
var Actions = require('./project-actions');
var MasonryMixin = require('./masonry-mixin.js');
var masonryOptions = {
transitionDuration: 0,
itemSelector: '.project-wrap'
};
function getProjects() {
return {projects:ProjectStore.getProjects()};
}
var Projects = React.createClass({
displayName: 'ProjectComponent',
mixins: [ProjectsWatchMixin(getProjects), MasonryMixin(masonryOptions)],
loadDemoData: function() {
Actions.loadDemoData();
},
submitNewProject: function(e) {
e.preventDefault();
var t = this.refs.title.getDOMNode();
if (t.value == '') return t.focus()
Actions.addProject({title:t.value})
},
render: function() {
var projectList = this.state.projects.map(function(project, i){
return (
<div className="project-wrap" key={i}>
<Project model={project} />
</div>
);
});
return (
<div ref="masonryContainer" className="projects">
<div className="project-wrap text-center">
<div className="project">
<header>
<h3>New Project</h3>
</header>
<form onSubmit={this.submitNewProject} className="input-group">
<input type="text" className="frm-ctrl" ref="title" />
<span className="input-group-addon">
<button type="submit" className="btn"><i className="fa fa-plus-circle" /></button>
</span>
</form>
</div>
</div>
<div>
{projectList}
</div>
</div>
);
}
});
module.exports = Projects;
project-component.js
/**
* @jsx React.DOM
*/
var React = require('react');
var Todos = require('../todos/todos-component');
var Project = React.createClass({
noop: function(e) {
e.preventDefault(); // yeah, yeah... not exactly noop!
},
render: function() {
var m = this.props.model;
var st = m.get('subTitle');
if (st) st = <small>{st}</small>
return (
<div className="project">
<header>
<h3>{m.get('title')} {st}</h3>
</header>
<p>{m.get('description')}</p>
<Todos projectId={m.get('id')} />
</div>
);
}
});
module.exports = Project;
todos-component.js
/**
* @jsx React.DOM
*/
var React = require('react');
var Todo = require('./todo-component');
var TodosWatchMixin = require('./todos-watch-mixin');
var TodoStore = require('./todos-store');
// var TodoActions = require('./todo-actions');
function getTodos(component) {
return {todos:TodoStore.getTodos(component.props.projectId)};
}
var TodoList = React.createClass({
mixins: [TodosWatchMixin(getTodos)],
render: function() {
var todoList = this.state.todos.map(function(t,i){
return <Todo key={i} model={t} />
});
return (
<ul className="todo-list">
{todoList}
</ul>
);
}
});
module.exports = TodoList;
projects-store.js
var Backbone = require('backbone');
var LocalStorage = require('backbone.localstorage');
var Dispatcher = require('./project-dispatcher');
var Constants = require('./project-constants');
// var Actions = require('../actions/app-actions');
var merge = require('react/lib/merge');
var EventEmitter = require('events').EventEmitter;
var TodoStore = require('../todos/todos-store');
var CHANGE_EVENT = "change";
if (window) window.Backbone = Backbone;
var Project = Backbone.Model.extend({
localStorage: new Backbone.LocalStorage("com.thomporter.todosApp.projects"),
defaults: {
sort_order: 0,
title: '',
subTitle: '',
description: ''
}
});
var Projects = Backbone.Collection.extend({
model: Project,
localStorage: new Backbone.LocalStorage("com.thomporter.todosApp.projects"),
initialize: function(){
this.comparator = this.comparatorDefault;
this.sort();
},
comparatorDefault: function (model) {
return model.get('sort_order');
}
});
var _projects = new Projects();
_projects.fetch();
var _demoDataLoaded = false;
function _loadDemoData () {
if (_demoDataLoaded) return;
_demoDataLoaded = true;
demo = require('./demo-data');
demo.projects.map(function(p, i){
var todos = p.todos
delete p.todos;
p.id = i+1000;
ProjectStore.addProject(p);
if (todos) {
todos.map(function(t){
t.project_id = p.id;
TodoStore.addTodo(t);
});
}
// _projects.sync();
});
};
function _addProject (project) {
if (!project.id) {
project.id = (new Date()).getTime();
}
var p = new Project(project);
p.save(project, {success:function(){
_projects.add(p);
ProjectStore.emitChange();
}});
};
function _removeProject () {
alert('Not Implemented Yet.');
};
var ProjectStore = merge(EventEmitter.prototype, {
emitChange:function(){
this.emit(CHANGE_EVENT)
},
addChangeListener:function(callback){
this.on(CHANGE_EVENT, callback)
},
removeChangeListener:function(callback){
this.removeListener(CHANGE_EVENT, callback)
},
get: function(id) {
return _projects.get(id);
},
getProjects: function() {
return _projects;
},
addProject: function(project) {
_addProject(project);
},
dipatcherIndex: Dispatcher.register(function(payload){
var action = payload.action;
switch(payload.action.actionType) {
case Constants.ADD_PROJECT:
_addProject(payload.action.project);
return; // will emit change after save success
case Constants.REMOVE_PROJECT:
_removeProject(payload.action.project);
break;
case Constants.LOAD_DEMO_DATA:
_loadDemoData();
break;
}
ProjectStore.emitChange();
return true;
}),
});
// _loadDemoData();
module.exports = ProjectStore;
if (window) window._projects = _projects;
可以看到the work in progress here .按 ctrl+shift+L
或 command+shift+L
加载测试数据,然后添加一个新项目,您可能会看到 Farm List 项目显示在你的新项目。
最佳答案
您正在使用 Array.map
调用的索引作为您的组件键。这意味着您的列表组件不能保证在每次渲染时都具有相同的键值。 React 在进行 diff 时在内部使用这些来协调 DOM,因此如果您使用数组索引作为键,每次呈现的内容都会不同。它在文档中明确提到:http://facebook.github.io/react/docs/multiple-components.html#dynamic-children .
您需要根据项目的自然 ID(即,不是数组索引)分配键,并确保它们是字符串(来自上面的链接):
Numeric properties will be ordered sequentially and before other properties. If this happens React will render components out of order. This can be avoided by adding a string prefix to the key
关于javascript - ReactJS 嵌套列表 (flux),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26365287/