tommy351/index.html

## index.html
<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>留言板</title>
	</head>
	<body>
		<% messages.forEach(function(line, i){ %>
			<p>
				<strong><%= line.author %></strong>: <%= line.content %>
				<a href="/delete/<%= i %>">刪除</a>
				<a href="/like/<%= i %>">Like (<%= line.likes %>)</a>
			</p>
		<% }) %>
		<form action="/" method="post">
			<input type="text" name="author" placeholder="作者">
			<input type="text" name="content" placeholder="內容">
			<button type="submit">送出</button>
		</form>
	</body>
</html>

## server.js
var express = require('express');
var fs = require('fs');
var app = express();

app.set('views', __dirname + '/views');
app.set('view engine', 'html');
app.engine('html', require('ejs').renderFile);

app.use(require('body-parser').urlencoded({
	extended: true
}));

app.get('/', function(req, res, next){
	fs.readFile('database.txt', 'utf8', function(err, content){
		var lines = content ? content.split('\n') : [];

		lines = lines.map(function(item){
			var line = item.split(':');

			return {author: line[0], content: line[1], likes: line[2]};
		});

		lines.pop();

		res.render('index', {messages: lines});
	});
});

app.post('/', function(req, res, next){
	var content = req.body.content;
	var author = req.body.author;

	fs.appendFile('database.txt', author + ':' + content + ':0\n', function(err){
		if (err) return next(err);
		res.redirect('/');
	});
});

app.get('/delete/:id', function(req, res, next){
	var line = req.params.id;

	fs.readFile('database.txt', 'utf8', function(err, content){
		if (!content) return res.redirect('/');

		var lines = content.split('\n');
		lines.splice(line, 1);

		fs.writeFile('database.txt', lines.join('\n'), function(err){
			if (err) return next(err);
			res.redirect('/');
		});
	});
});

app.get('/like/:id', function(req, res, next){
	var line = req.params.id;

	fs.readFile('database.txt', 'utf8', function(err, content){
		if (!content) return res.redirect('/');

		var lines = content.split('\n');
		var item = lines[line].split(':');
		var likes = parseInt(item[2]) || 0;

		item[2] = likes + 1;

		lines[line] = item.join(':');

		fs.writeFile('database.txt', lines.join('\n'), function(err){
			if (err) return next(err);
			res.redirect('/');
		})
	});
});

app.listen(4000, function(){
	console.log('Server started');
});
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<title>留言板</title>
	</head>
	<body>
	<% messages.forEach(function(line, i){ %>
	<p>
	<strong><%= line.author %></strong>: <%= line.content %>
	<a href="/delete/<%= i %>">刪除</a>
	<a href="/like/<%= i %>">Like (<%= line.likes %>)</a>
	</p>
	<% }) %>
	<form action="/" method="post">
	<input type="text" name="author" placeholder="作者">
	<input type="text" name="content" placeholder="內容">
	<button type="submit">送出</button>
	</form>
	</body>
	</html>
	var express = require('express');
	var fs = require('fs');
	var app = express();

	app.set('views', __dirname + '/views');
	app.set('view engine', 'html');
	app.engine('html', require('ejs').renderFile);

	app.use(require('body-parser').urlencoded({
	extended: true
	}));

	app.get('/', function(req, res, next){
	fs.readFile('database.txt', 'utf8', function(err, content){
	var lines = content ? content.split('\n') : [];

	lines = lines.map(function(item){
	var line = item.split(':');

	return {author: line[0], content: line[1], likes: line[2]};
	});

	lines.pop();

	res.render('index', {messages: lines});
	});
	});

	app.post('/', function(req, res, next){
	var content = req.body.content;
	var author = req.body.author;

	fs.appendFile('database.txt', author + ':' + content + ':0\n', function(err){
	if (err) return next(err);
	res.redirect('/');
	});
	});

	app.get('/delete/:id', function(req, res, next){
	var line = req.params.id;

	fs.readFile('database.txt', 'utf8', function(err, content){
	if (!content) return res.redirect('/');

	var lines = content.split('\n');
	lines.splice(line, 1);

	fs.writeFile('database.txt', lines.join('\n'), function(err){
	if (err) return next(err);
	res.redirect('/');
	});
	});
	});

	app.get('/like/:id', function(req, res, next){
	var line = req.params.id;

	fs.readFile('database.txt', 'utf8', function(err, content){
	if (!content) return res.redirect('/');

	var lines = content.split('\n');
	var item = lines[line].split(':');
	var likes = parseInt(item[2]) \|\| 0;

	item[2] = likes + 1;

	lines[line] = item.join(':');

	fs.writeFile('database.txt', lines.join('\n'), function(err){
	if (err) return next(err);
	res.redirect('/');
	})
	});
	});

	app.listen(4000, function(){
	console.log('Server started');
	});