koa-lite/examples/compose.js

59 lines
984 B
JavaScript

var compose = require('koa-compose');
var http = require('http');
var koa = require('..');
var app = koa();
var calls = [];
// x-response-time
function responseTime(){
return function responseTime(next){
return function *(){
var start = new Date;
yield next;
var ms = new Date - start;
this.set('X-Response-Time', ms + 'ms');
}
}
}
// logger
function logger(){
return 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);
}
}
}
// response
function respond() {
return function respond(next){
return function *(){
yield next;
if ('/' != this.url) return;
this.body = 'Hello World';
}
}
}
// composed middleware
function all() {
return compose([
responseTime(),
logger(),
respond()
]);
}
app.use(all());
http.createServer(app.callback()).listen(3000);