Clicky

React Simple sample collection


I participated in the React Hands-on so I would like to leave that memorandum.

React initial setting

  • Installation
$ npm install -g create-react-app
  • Establishment of the environment at the workplace
$ create-react-app myapp
$ cd myapp
$ npm start
  • Route point
ReactDOM.render(
  <App />,
  document.getElementById('root')
);

Make characters tick

· How to write characters using the setInterval function

import React, { Component } from 'react';
import Text from './Text';
class App extends Component {
  render() {
    return (
      <div>
        <Text text='sentence' />
      </div>
    )
  }
}
export default App;
import React, { Component } from 'react';
class Text extends Component {
  constructor(props) {
    super(props);
    this.state = {
      showText: true,
    };
    setInterval(() => {
      this.setState({
        showText: !this.state.showText,
      });
    }, 1000);
  }
  render() {
    const text = this.state.showText? this.props.text : '';
    return (
      <div>
        {text}
      </div>
    )
  }
}
export default Text;

Click count

import React, { Component } from 'react';
import Button from './Button';
class App extends Component {
  render() {
    return (
      <div>
        <Button />
      </div>
    )
  }
}
export default App;
import React, { Component } from 'react';
class Button extends Component {
  constructor(props) {
    super(props);
    this.state = {
      count: 0,
    }
    this._addCount = this._addCount.bind(this); // イベントハンドラでthisをbindさせるため
  }
  _addCount() {
    this.setState({
      count: this.state.count + 1,
    });
  }
  render() {
    return (
      <div>
        <button onClick={this._addCount}>
          button
        </button>
        <p>{this.state.count}</p>
      </div>
    )
  }
}
 export default Button;

How to write other bind

· Write onClick

<button onClick={this._addCount.bind(this)}>

· Write with arrow function (bind unnecessary)

_addCount = () => {
  this.setState({
    count: this.state.count + 1,
  });
}