Koa.js - Request Object

A Koa Request object is an abstraction on top of node's vanilla request object, providing additional functionality that is useful for every day HTTP server development. The Koa request object is embeded in the context object, this. Lets log out the request object whenever we get a request:

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

var _ = router();

_.get('/hello', getMessage);

function *getMessage(){
    console.log(this.request);
    this.body = 'Your request has been logged.';
}

app.use(_.routes());

app.listen(3000);

When you run this code and navigate to https://localhost:3000/hello then you'll get the response:
On your console, you'll get the request object logged out:

{ 
    method: 'GET',
    url: '/hello/',
    header: 
    { 
        host: 'localhost:3000',
        connection: 'keep-alive',
        'upgrade-insecure-requests': '1',
        'user-agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36',
        accept: 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
        dnt: '1',
        'accept-encoding': 'gzip, deflate, sdch',
        'accept-language': 'en-US,en;q=0.8' 
    }
}

We have access to many useful properties of the request using this object. Let us look at some examples:

request.header

Gives us all the request headers.

request.method

Gives us the request method(GET, POST, etc.)

request.href

Gives us the full request URL.

request.path

Gives us just the path of the request. Without query string and base url.

request.query

Gives us the parsed query string. For example if we log this on a request like https://localhost:3000/hello/?name=Ayush&age=20&country=India, then we'll get the following object:

{
    name: 'Ayush',
    age: '20',
    country: 'India'
}

request.accepts(type)

This function returns true or false based on whether the requested resources accepts the given request type.
You can read more about the request object in the docs at Request.