Connect中间件——重写URL

// 重写URL
// 基于URL最后的文章标题查找文章的ID，然后将URL转换成/blog/posts/

var connect = require('connect');
var url = require('url');
var app = connect()
.use(rewrite)
.use(showPost)
.listen(3000);

function rewrite(req, res, next) {
var path = url.parse(req.url).pathname;
var match = path.match(/^\/blog\/post\/(.+)/);
if (match) {
findPostIdBySlug(match[1], function(err, id) {
if (err) return next(err);
if (!id) return next(new Error('User not found'));
req.url = '/blog/posts/' + id;
next();
});
} else {
next();
}
}