koa-routing

Routing middleware for Koa

koa-routing

npm install koa-routing

I wanted to separate my route definitions into multiple files. Also I wanted to make easier to specify route handlers, and execute some methods before some set of routes, for example ensuring that user is authenticated before doing some action. So I developed koa-r and koa-routing to achieve that. Final result is something like this:

/routing/index.js file

module.exports = function (app) {
  require('./users')(app.route('/api/users').before(authenticate));
};

/routing/users.js file

/**
 * /api/users
 */
 
module.exports = function (route) {
  /* GET /api/users */
  route.get(r('user', 'getUsers'));
 
  /* GET /api/users/logout */
  route.nested('/logout').get(r('user', 'logout'));
};

So here you can see that we are specifying handlers for route with r('module', 'method') pattern, and we are also following DRY principle when we define our routes.

If you like this idea, you are on right place.

Let's define following routes:

  • /users [GET, POST, PUT],
  • /users/list [GET, PUT]

With koa-routing you can nest routes, and on that way you can follow DRY principle. Also koa-routing architecture help you to separate route handlers into multiple files. That example will be shown also.

var koa = require('koa'),
    routing = require('koa-routing');
 
var app = koa();
app.use(routing(app));
 
app.route('/users')
  .get(function * (next) {
    this.body = 'from get';
    yield next;
  })
  .post(function * (next) {
    this.body = 'from post';
    yield next;
  })
  .put(function * (next) {
    this.body = 'from put';
    yield next;
  })
  .nested('/list')
    .get(function * (next) {
      this.body = 'from users list GET';
      yield next;
    });
    .put(function * (next) {
      this.body = 'from users list PUT';
      yield next;
    });
 
app.listen(4000);

You should put koa-routing middleware after body parsers and simmilar middlewares which are preparing request for you, or passing an options object with a defer field setted to true.

As you can see, you can pass classic express route style, such as /user/:id, and after that you can read received values from this.params or this.request.params object.

You can pass also regex as route path.

koa-routing extends you application instance with route method. You can use that method for defining route path.

app.route('/users/:id');

After you define your route, you need set HTTP methods for that route. In following example you need to replace someHTTPmethod with one of supported node HTTP methods. That can be GET, POST, PUT, etc...

app.route('route path').someHTTPmethod(handler);

So you can type something like:

var handler = function * () {
  yield next;
};
 
app.route('api/users').get(handler);

Keep in mind that every call returns router instance, so everything can be chained.

Let's we say that you have for routes something like this:

  • /api/users/profile/data
  • /api/users/profile/image
  • etc.

You see that you are repeating /api/users/profile for every route, and we don't want to do that. koa-routing have nice solution for this with nested function.

// first you type fixed part
var route = app.route('/api/users/profile');
 
route.nested('/data')
  .get(function * (next) { yield next; });
  // here you can also define other HTTP operations, like POST, PUT, etc
  // example of put...
  .put(function * (next) { yield next; });
 
route.nested('/image')
  .get(function * (next) { yield next; });

Keep in mind that nested creates new route for you and returns created route. You can continue nesting routes. It is up to you.

You can define function which will be executed before each route method, and before all nested routes.

app.route('/someRoute')
    .before(function * (next) {
        this.status = 300;
    })
    .get(function * (next) {
        this.body = 'should not be here';
        this.status = 200;
        yield next;
    });

This function will be executed if there is no matching HTTP method.

app.route('/someRoute')
    .all(function * (next) {
        this.body = 'will catch GET/POST/PUT... etc';
        this.status = 200;
        yield next;
    })

With koa-routing you can provide multiple middlewares for each route method:

app.route('/multipleMiddleware')
    .get(function * (next) {
        this.body = '1';
        this.status = 200;
        yield next;
    }, function * (next) {
        this.body = '2';
        yield next;
    });

If you go to this route you will receive 2 as a result, because request will be passed to each defined handler.

app.use(routing(app,options));
  • defer Default is false. If true, serves after yield next, allowing any downstream middleware to respond first.

Feel free to send pull request with some new awesome feature or some bug fix. But please provide some tests with your contribution.

License

MIT