koa-4.js

"use strict";

var koa = require('koa');
var app = koa();

var bodyParser = require('koa-bodyparser');
var fs = require('fs');


app.use(bodyParser());
app.use(function*(next) {
	if (this.path !== '/') {
		return yield next;
	};
	var name = this.request.body.name;
	this.body = name.toUpperCase();
});

app.use(function*(next) {
	if (this.path !== '/json') {
		yield next;
	};
	this.body = { foo: 'bar'};
});

app.use(function*(next) {
	if (this.path !== '/stream') {
		yield next;
	};

	this.body =	fs.createReadStream(process.argv[3]);
})

app.use(handler404);
app.use(hander500);

function* handler404 (next) {
	if (this.path !== '/404') {
		return yield next;
	};
	this.body = 'page not found';
}

function* hander500 (next) {
	if (this.path !== '/500') {
		return yield next;
	};
	this.body = 'internal server error';
}
var port = process.argv[2];
app.listen(port);