229 lines
7.3 KiB
Markdown
229 lines
7.3 KiB
Markdown
---
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id: 5a24c314108439a4d4036144
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title: Use Provider to Connect Redux to React
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challengeType: 6
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isRequired: false
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forumTopicId: 301435
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localeTitle: Использовать Провайдер для подключения Redux к действию
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---
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## Description
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<section id='description'>
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В последней задаче вы создали хранилище Redux для обработки массива сообщений и создали действие для добавления новых сообщений. Следующим шагом будет предоставление доступа React к хранилищу Redux и действия, необходимые для отправки обновлений. React Redux предоставляет пакет <code>react-redux</code> для выполнения этих задач. React Redux предоставляет небольшой API с двумя ключевыми функциями: <code>Provider</code> и <code>connect</code> . Другая проблема <code>connect</code> . <code>Provider</code> - это оболочка из React Redux, которая обертывает ваше приложение React. Затем этот обертку позволяет вам получить доступ к функциям <code>store</code> Redux и функции <code>dispatch</code> во всем дереве компонентов. <code>Provider</code> берет два реквизита, магазин Redux и дочерние компоненты вашего приложения. Определение <code>Provider</code> для компонента приложения может выглядеть так: <blockquote> <Магазин-провайдер = {store}> <br> <Приложение /> <br> </ Provider> </blockquote>
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</section>
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## Instructions
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<section id='instructions'>
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The code editor now shows all your Redux and React code from the past several challenges. It includes the Redux store, actions, and the <code>DisplayMessages</code> component. The only new piece is the <code>AppWrapper</code> component at the bottom. Use this top level component to render the <code>Provider</code> from <code>ReactRedux</code>, and pass the Redux store as a prop. Then render the <code>DisplayMessages</code> component as a child. Once you are finished, you should see your React component rendered to the page.
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<strong>Note:</strong> React Redux is available as a global variable here, so you can access the Provider with dot notation. The code in the editor takes advantage of this and sets it to a constant <code>Provider</code> for you to use in the <code>AppWrapper</code> render method.
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: The <code>AppWrapper</code> should render.
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testString: assert((function() { const mockedComponent = Enzyme.mount(React.createElement(AppWrapper)); return mockedComponent.find('AppWrapper').length === 1; })());
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- text: The <code>Provider</code> wrapper component should have a prop of <code>store</code> passed to it, equal to the Redux store.
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testString: getUserInput => assert((function() { const mockedComponent = Enzyme.mount(React.createElement(AppWrapper)); return getUserInput('index').replace(/\s/g,'').includes('<Providerstore={store}>'); })());
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- text: <code>DisplayMessages</code> should render as a child of <code>AppWrapper</code>.
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testString: assert((function() { const mockedComponent = Enzyme.mount(React.createElement(AppWrapper)); return mockedComponent.find('AppWrapper').find('DisplayMessages').length === 1; })());
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- text: The <code>DisplayMessages</code> component should render an h2, input, button, and <code>ul</code> element.
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testString: assert((function() { const mockedComponent = Enzyme.mount(React.createElement(AppWrapper)); return mockedComponent.find('div').length === 1 && mockedComponent.find('h2').length === 1 && mockedComponent.find('button').length === 1 && mockedComponent.find('ul').length === 1; })());
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='jsx-seed'>
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```jsx
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// Redux Code:
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const ADD = 'ADD';
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const addMessage = (message) => {
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return {
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type: ADD,
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message
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}
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};
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const messageReducer = (state = [], action) => {
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switch (action.type) {
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case ADD:
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return [
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...state,
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action.message
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];
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default:
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return state;
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}
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};
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const store = Redux.createStore(messageReducer);
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// React Code:
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class DisplayMessages extends React.Component {
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constructor(props) {
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super(props);
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this.state = {
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input: '',
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messages: []
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}
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this.handleChange = this.handleChange.bind(this);
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this.submitMessage = this.submitMessage.bind(this);
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}
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handleChange(event) {
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this.setState({
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input: event.target.value
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});
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}
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submitMessage() {
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const currentMessage = this.state.input;
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this.setState({
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input: '',
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messages: this.state.messages.concat(currentMessage)
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});
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}
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render() {
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return (
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<div>
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<h2>Type in a new Message:</h2>
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<input
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value={this.state.input}
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onChange={this.handleChange}/><br/>
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<button onClick={this.submitMessage}>Submit</button>
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<ul>
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{this.state.messages.map( (message, idx) => {
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return (
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<li key={idx}>{message}</li>
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)
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})
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}
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</ul>
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</div>
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);
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}
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};
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const Provider = ReactRedux.Provider;
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class AppWrapper extends React.Component {
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// render the Provider here
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// change code above this line
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};
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```
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</div>
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### After Tests
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<div id='jsx-teardown'>
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```jsx
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ReactDOM.render(<AppWrapper />, document.getElementById('root'))
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```jsx
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// Redux Code:
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const ADD = 'ADD';
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const addMessage = (message) => {
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return {
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type: ADD,
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message
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}
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};
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const messageReducer = (state = [], action) => {
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switch (action.type) {
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case ADD:
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return [
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...state,
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action.message
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];
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default:
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return state;
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}
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};
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const store = Redux.createStore(messageReducer);
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// React Code:
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class DisplayMessages extends React.Component {
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constructor(props) {
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super(props);
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this.state = {
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input: '',
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messages: []
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}
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this.handleChange = this.handleChange.bind(this);
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this.submitMessage = this.submitMessage.bind(this);
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}
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handleChange(event) {
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this.setState({
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input: event.target.value
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});
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}
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submitMessage() {
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const currentMessage = this.state.input;
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this.setState({
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input: '',
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messages: this.state.messages.concat(currentMessage)
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});
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}
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render() {
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return (
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<div>
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<h2>Type in a new Message:</h2>
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<input
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value={this.state.input}
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onChange={this.handleChange}/><br/>
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<button onClick={this.submitMessage}>Submit</button>
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<ul>
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{this.state.messages.map( (message, idx) => {
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return (
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<li key={idx}>{message}</li>
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)
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})
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}
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</ul>
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</div>
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);
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}
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};
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const Provider = ReactRedux.Provider;
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class AppWrapper extends React.Component {
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// change code below this line
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render() {
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return (
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<Provider store = {store}>
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<DisplayMessages/>
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</Provider>
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);
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}
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// change code above this line
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};
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```
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</section>
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