saitoxu/Board.js

## Board.js
import React, { Component } from 'react';
import Square from './Square';

class Board extends Component {
  renderSquare(i) {
    return <Square value={this.props.squares[i]} onClick={() => this.props.onClick(i)} />;
  }

  render() {
    return (
      <div>
        <div className="board-row">
          {this.renderSquare(0)}
          {this.renderSquare(1)}
          {this.renderSquare(2)}
        </div>
        <div className="board-row">
          {this.renderSquare(3)}
          {this.renderSquare(4)}
          {this.renderSquare(5)}
        </div>
        <div className="board-row">
          {this.renderSquare(6)}
          {this.renderSquare(7)}
          {this.renderSquare(8)}
        </div>
      </div>
    );
  }
}

export default Board;

## create-react-app.sh
$ yarn global add create-react-app
$ create-react-app react-tic-tac-toe
$ cd react-tic-tac-toe
$ yarn start

## Game.js
import React, { Component } from 'react';
import Board from './Board';

class Game extends Component {
  constructor() {
    super();
    this.state = {
      stepNumber: 0,
      history: [{
        squares: Array(9).fill(null)
      }],
      xIsNext: true
    };
  }

  handleClick(i) {
    const history = this.state.history.slice(0, this.state.stepNumber + 1);
    const current = history[this.state.stepNumber];
    const squares = current.squares.slice();
    if (calculateWinner(squares) || squares[i]) {
      return;
    }
    squares[i] = this.state.xIsNext ? 'X' : 'O';
    this.setState({
      stepNumber: history.length,
      history: history.concat([{
        squares: squares
      }]),
      xIsNext: !this.state.xIsNext,
    });
  }

  jumpTo(step) {
    this.setState({
      stepNumber: step,
      xIsNext: (step % 2) ? false : true
    });
  }

  render() {
    const history = this.state.history;
    const current = history[this.state.stepNumber];
    const winner = calculateWinner(current.squares);

    let status;
    if (winner) {
      status = 'Winner: ' + winner;
    } else {
      status = 'Next player: ' + (this.state.xIsNext? 'X' : 'O');
    }

    const moves = history.map((step, move) => {
      const desc = move ? 'Move #' + move : 'Game start';
      return (
        <li key={move}>
          <a href="#" onClick={() => this.jumpTo(move)}>{desc}</a>
        </li>
      );
    });

    return (
      <div className="game">
        <div className="game-board">
          <Board
            squares={current.squares}
            onClick={(i) => this.handleClick(i)}
          />
        </div>
        <div className="game-info">
          <div>{status}</div>
          <ol>{moves}</ol>
        </div>
      </div>
    );
  }
}

function calculateWinner(squares) {
  const lines = [
    [0, 1, 2],
    [3, 4, 5],
    [6, 7, 8],
    [0, 3, 6],
    [1, 4, 7],
    [2, 5, 8],
    [0, 4, 8],
    [2, 4, 6],
  ];
  for (let i = 0; i < lines.length; i++) {
    const [a, b, c] = lines[i];
    if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
      return squares[a];
    }
  }
  return null;
}

export default Game;

## index.css
body {
  font: 14px "Century Gothic", Futura, sans-serif;
  margin: 20px;
}

ol, ul {
  padding-left: 30px;
}

.board-row:after {
  clear: both;
  content: "";
  display: table;
}

.status {
  margin-bottom: 10px;
}

.square {
  background: #fff;
  border: 1px solid #999;
  float: left;
  font-size: 24px;
  font-weight: bold;
  line-height: 34px;
  height: 34px;
  margin-right: -1px;
  margin-top: -1px;
  padding: 0;
  text-align: center;
  width: 34px;
}

.square:focus {
  outline: none;
}

.kbd-navigation .square:focus {
  background: #ddd;
}

.game {
  display: flex;
  flex-direction: row;
}

.game-info {
  margin-left: 20px;
}

## index.html
<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
    <title>react-tic-tac-toe</title>
  </head>
  <body>
    <div id="errors" style="
      background: #c00;
      color: #fff;
      display: none;
      margin: -20px -20px 20px;
      padding: 20px;
      white-space: pre-wrap;
    "></div>
    <div id="root"></div>
    <script>
      window.addEventListener('mousedown', function(e) {
        document.body.classList.add('mouse-navigation');
        document.body.classList.remove('kbd-navigation');
      });
      window.addEventListener('keydown', function(e) {
        if (e.keyCode === 9) {
          document.body.classList.add('kbd-navigation');
          document.body.classList.remove('mouse-navigation');
        }
      });
      window.addEventListener('click', function(e) {
        if (e.target.tagName === 'A' && e.target.getAttribute('href') === '#') {
          e.preventDefault();
        }
      });
      window.onerror = function(message, source, line, col, error) {
        var text = error ? error.stack || error : message + ' (at ' + source + ':' + line + ':' + col + ')';
        errors.textContent += text + '\n';
        errors.style.display = '';
      };
      console.error = (function(old) {
        return function error() {
          errors.textContent += Array.prototype.slice.call(arguments).join(' ') + '\n';
          errors.style.display = '';
          old.apply(this, arguments);
        }
      })(console.error);
    </script>
  </body>
</html>

## index.js
import React from 'react';
import ReactDOM from 'react-dom';
import Game from './Game';
import './index.css';

ReactDOM.render(
  <Game />,
  document.getElementById('root')
);

## Square.js
import React from 'react';

function Square(props) {
  return (
    <button className="square" onClick={() => props.onClick()}>
      {props.value}
    </button>
  );
}

export default Square;
	import React, { Component } from 'react';
	import Square from './Square';

	class Board extends Component {
	renderSquare(i) {
	return <Square value={this.props.squares[i]} onClick={() => this.props.onClick(i)} />;
	}

	render() {
	return (
	<div>
	<div className="board-row">
	{this.renderSquare(0)}
	{this.renderSquare(1)}
	{this.renderSquare(2)}
	</div>
	<div className="board-row">
	{this.renderSquare(3)}
	{this.renderSquare(4)}
	{this.renderSquare(5)}
	</div>
	<div className="board-row">
	{this.renderSquare(6)}
	{this.renderSquare(7)}
	{this.renderSquare(8)}
	</div>
	</div>
	);
	}
	}

	export default Board;
	$ yarn global add create-react-app
	$ create-react-app react-tic-tac-toe
	$ cd react-tic-tac-toe
	$ yarn start
	import React, { Component } from 'react';
	import Board from './Board';

	class Game extends Component {
	constructor() {
	super();
	this.state = {
	stepNumber: 0,
	history: [{
	squares: Array(9).fill(null)
	}],
	xIsNext: true
	};
	}

	handleClick(i) {
	const history = this.state.history.slice(0, this.state.stepNumber + 1);
	const current = history[this.state.stepNumber];
	const squares = current.squares.slice();
	if (calculateWinner(squares) \|\| squares[i]) {
	return;
	}
	squares[i] = this.state.xIsNext ? 'X' : 'O';
	this.setState({
	stepNumber: history.length,
	history: history.concat([{
	squares: squares
	}]),
	xIsNext: !this.state.xIsNext,
	});
	}

	jumpTo(step) {
	this.setState({
	stepNumber: step,
	xIsNext: (step % 2) ? false : true
	});
	}

	render() {
	const history = this.state.history;
	const current = history[this.state.stepNumber];
	const winner = calculateWinner(current.squares);

	let status;
	if (winner) {
	status = 'Winner: ' + winner;
	} else {
	status = 'Next player: ' + (this.state.xIsNext? 'X' : 'O');
	}

	const moves = history.map((step, move) => {
	const desc = move ? 'Move #' + move : 'Game start';
	return (
	<li key={move}>
	<a href="#" onClick={() => this.jumpTo(move)}>{desc}</a>
	</li>
	);
	});

	return (
	<div className="game">
	<div className="game-board">
	<Board
	squares={current.squares}
	onClick={(i) => this.handleClick(i)}
	/>
	</div>
	<div className="game-info">
	<div>{status}</div>
	<ol>{moves}</ol>
	</div>
	</div>
	);
	}
	}

	function calculateWinner(squares) {
	const lines = [
	[0, 1, 2],
	[3, 4, 5],
	[6, 7, 8],
	[0, 3, 6],
	[1, 4, 7],
	[2, 5, 8],
	[0, 4, 8],
	[2, 4, 6],
	];
	for (let i = 0; i < lines.length; i++) {
	const [a, b, c] = lines[i];
	if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
	return squares[a];
	}
	}
	return null;
	}

	export default Game;
	body {
	font: 14px "Century Gothic", Futura, sans-serif;
	margin: 20px;
	}

	ol, ul {
	padding-left: 30px;
	}

	.board-row:after {
	clear: both;
	content: "";
	display: table;
	}

	.status {
	margin-bottom: 10px;
	}

	.square {
	background: #fff;
	border: 1px solid #999;
	float: left;
	font-size: 24px;
	font-weight: bold;
	line-height: 34px;
	height: 34px;
	margin-right: -1px;
	margin-top: -1px;
	padding: 0;
	text-align: center;
	width: 34px;
	}

	.square:focus {
	outline: none;
	}

	.kbd-navigation .square:focus {
	background: #ddd;
	}

	.game {
	display: flex;
	flex-direction: row;
	}

	.game-info {
	margin-left: 20px;
	}
	<!doctype html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
	<title>react-tic-tac-toe</title>
	</head>
	<body>
	<div id="errors" style="
	background: #c00;
	color: #fff;
	display: none;
	margin: -20px -20px 20px;
	padding: 20px;
	white-space: pre-wrap;
	"></div>
	<div id="root"></div>
	<script>
	window.addEventListener('mousedown', function(e) {
	document.body.classList.add('mouse-navigation');
	document.body.classList.remove('kbd-navigation');
	});
	window.addEventListener('keydown', function(e) {
	if (e.keyCode === 9) {
	document.body.classList.add('kbd-navigation');
	document.body.classList.remove('mouse-navigation');
	}
	});
	window.addEventListener('click', function(e) {
	if (e.target.tagName === 'A' && e.target.getAttribute('href') === '#') {
	e.preventDefault();
	}
	});
	window.onerror = function(message, source, line, col, error) {
	var text = error ? error.stack \|\| error : message + ' (at ' + source + ':' + line + ':' + col + ')';
	errors.textContent += text + '\n';
	errors.style.display = '';
	};
	console.error = (function(old) {
	return function error() {
	errors.textContent += Array.prototype.slice.call(arguments).join(' ') + '\n';
	errors.style.display = '';
	old.apply(this, arguments);
	}
	})(console.error);
	</script>
	</body>
	</html>
	import React from 'react';
	import ReactDOM from 'react-dom';
	import Game from './Game';
	import './index.css';

	ReactDOM.render(
	<Game />,
	document.getElementById('root')
	);
	import React from 'react';

	function Square(props) {
	return (
	<button className="square" onClick={() => props.onClick()}>
	{props.value}
	</button>
	);
	}

	export default Square;