koa-lite/examples/conditional-middleware.js

33 lines
616 B
JavaScript

var http = require('http');
var koa = require('..');
var app = koa();
// logger
function logger(next){
return function *(){
var start = new Date;
yield next;
var ms = new Date - start;
console.log('%s %s - %s', this.method, this.url, ms);
}
}
// sometimes it's useful to apply some
// ad-hoc logic to enable middleware, for
// example ignoring a logger on asset requests:
app.use(function(next){
return function *(){
if (/(\.js|\.css|\.ico)$/.test(this.path)) {
yield next;
} else {
this.body = 'Hello World';
yield logger(next);
}
}
});
app.listen(3000);