Awesome

koa-router

Router middleware for koa

• Express-style routing using app.get, app.put, app.post, etc.
• Named URL parameters.
• Named routes with URL generation.
• Responds to OPTIONS requests with allowed methods.
• Support for 405 Method Not Allowed and 501 Not Implemented.
• Multiple route middleware.
• Multiple routers.
• Nestable routers.
• ES7 async/await support.

Migrating to 7 / Koa 2

• The API has changed to match the new promise-based middleware signature of koa 2. See the koa 2.x readme for more information.
• Middleware is now always run in the order declared by .use() (or .get(), etc.), which matches Express 4 API.

Installation

Install using npm:

npm install koa-router

API Reference

• koa-router
  • Router ⏏
    • new Router([opts])
    • instance
      • .get|put|post|patch|delete|del ⇒ <code>Router</code>
      • .routes ⇒ <code>function</code>
      • .use([path], middleware) ⇒ <code>Router</code>
      • .prefix(prefix) ⇒ <code>Router</code>
      • .allowedMethods([options]) ⇒ <code>function</code>
      • .redirect(source, destination, [code]) ⇒ <code>Router</code>
      • .route(name) ⇒ <code>Layer</code> | <code>false</code>
      • .url(name, params, [options]) ⇒ <code>String</code> | <code>Error</code>
      • .param(param, middleware) ⇒ <code>Router</code>
    • static
      • .url(path, params) ⇒ <code>String</code>

<a name="exp_module_koa-router--Router"></a>

Router ⏏

Kind: Exported class
<a name="new_module_koa-router--Router_new"></a>

new Router([opts])

Create a new router.

Example
Basic usage:

var Koa = require('koa');
var Router = require('koa-router');

var app = new Koa();
var router = new Router();

router.get('/', (ctx, next) => {
  // ctx.router available
});

app
  .use(router.routes())
  .use(router.allowedMethods());

<a name="module_koa-router--Router+get|put|post|patch|delete|del"></a>

router.get|put|post|patch|delete|del ⇒ <code>Router</code>

Create router.verb() methods, where verb is one of the HTTP verbs such as router.get() or router.post().

Match URL patterns to callback functions or controller actions using router.verb(), where verb is one of the HTTP verbs such as router.get() or router.post().

Additionaly, router.all() can be used to match against all methods.

router
  .get('/', (ctx, next) => {
    ctx.body = 'Hello World!';
  })
  .post('/users', (ctx, next) => {
    // ...
  })
  .put('/users/:id', (ctx, next) => {
    // ...
  })
  .del('/users/:id', (ctx, next) => {
    // ...
  })
  .all('/users/:id', (ctx, next) => {
    // ...
  });

When a route is matched, its path is available at ctx._matchedRoute and if named, the name is available at ctx._matchedRouteName

Route paths will be translated to regular expressions using path-to-regexp.

Query strings will not be considered when matching requests.

Named routes

Routes can optionally have names. This allows generation of URLs and easy renaming of URLs during development.

router.get('user', '/users/:id', (ctx, next) => {
 // ...
});

router.url('user', 3);
// => "/users/3"

Multiple middleware

Multiple middleware may be given:

router.get(
  '/users/:id',
  (ctx, next) => {
    return User.findOne(ctx.params.id).then(function(user) {
      ctx.user = user;
      next();
    });
  },
  ctx => {
    console.log(ctx.user);
    // => { id: 17, name: "Alex" }
  }
);

Nested routers

Nesting routers is supported:

var forums = new Router();
var posts = new Router();

posts.get('/', (ctx, next) => {...});
posts.get('/:pid', (ctx, next) => {...});
forums.use('/forums/:fid/posts', posts.routes(), posts.allowedMethods());

// responds to "/forums/123/posts" and "/forums/123/posts/123"
app.use(forums.routes());

Router prefixes

Route paths can be prefixed at the router level:

var router = new Router({
  prefix: '/users'
});

router.get('/', ...); // responds to "/users"
router.get('/:id', ...); // responds to "/users/:id"

URL parameters

Named route parameters are captured and added to ctx.params.

router.get('/:category/:title', (ctx, next) => {
  console.log(ctx.params);
  // => { category: 'programming', title: 'how-to-node' }
});

The path-to-regexp module is used to convert paths to regular expressions.

Kind: instance property of <code>Router</code>

<a name="module_koa-router--Router+routes"></a>

router.routes ⇒ <code>function</code>

Returns router middleware which dispatches a route matching the request.

Kind: instance property of <code>Router</code>
<a name="module_koa-router--Router+use"></a>

router.use([path], middleware) ⇒ <code>Router</code>

Use given middleware.

Middleware run in the order they are defined by .use(). They are invoked sequentially, requests start at the first middleware and work their way "down" the middleware stack.

Kind: instance method of <code>Router</code>

Example

// session middleware will run before authorize
router
  .use(session())
  .use(authorize());

// use middleware only with given path
router.use('/users', userAuth());

// or with an array of paths
router.use(['/users', '/admin'], userAuth());

app.use(router.routes());

<a name="module_koa-router--Router+prefix"></a>

router.prefix(prefix) ⇒ <code>Router</code>

Set the path prefix for a Router instance that was already initialized.

Kind: instance method of <code>Router</code>

Example

router.prefix('/things/:thing_id')

<a name="module_koa-router--Router+allowedMethods"></a>

router.allowedMethods([options]) ⇒ <code>function</code>

Returns separate middleware for responding to OPTIONS requests with an Allow header containing the allowed methods, as well as responding with 405 Method Not Allowed and 501 Not Implemented as appropriate.

Kind: instance method of <code>Router</code>

Example

var Koa = require('koa');
var Router = require('koa-router');

var app = new Koa();
var router = new Router();

app.use(router.routes());
app.use(router.allowedMethods());

Example with Boom

var Koa = require('koa');
var Router = require('koa-router');
var Boom = require('boom');

var app = new Koa();
var router = new Router();

app.use(router.routes());
app.use(router.allowedMethods({
  throw: true,
  notImplemented: () => new Boom.notImplemented(),
  methodNotAllowed: () => new Boom.methodNotAllowed()
}));

<a name="module_koa-router--Router+redirect"></a>

router.redirect(source, destination, [code]) ⇒ <code>Router</code>

Redirect source to destination URL with optional 30x status code.

Both source and destination can be route names.

router.redirect('/login', 'sign-in');

This is equivalent to:

router.all('/login', ctx => {
  ctx.redirect('/sign-in');
  ctx.status = 301;
});

Kind: instance method of <code>Router</code>

<a name="module_koa-router--Router+route"></a>

router.route(name) ⇒ <code>Layer</code> | <code>false</code>

Lookup route with given name.

Kind: instance method of <code>Router</code>

<a name="module_koa-router--Router+url"></a>

router.url(name, params, [options]) ⇒ <code>String</code> | <code>Error</code>

Generate URL for route. Takes a route name and map of named params.

Kind: instance method of <code>Router</code>

Example

router.get('user', '/users/:id', (ctx, next) => {
  // ...
});

router.url('user', 3);
// => "/users/3"

router.url('user', { id: 3 });
// => "/users/3"

router.use((ctx, next) => {
  // redirect to named route
  ctx.redirect(ctx.router.url('sign-in'));
})

router.url('user', { id: 3 }, { query: { limit: 1 } });
// => "/users/3?limit=1"

router.url('user', { id: 3 }, { query: "limit=1" });
// => "/users/3?limit=1"

<a name="module_koa-router--Router+param"></a>

router.param(param, middleware) ⇒ <code>Router</code>

Run middleware for named route parameters. Useful for auto-loading or validation.

Kind: instance method of <code>Router</code>

Example

router
  .param('user', (id, ctx, next) => {
    ctx.user = users[id];
    if (!ctx.user) return ctx.status = 404;
    return next();
  })
  .get('/users/:user', ctx => {
    ctx.body = ctx.user;
  })
  .get('/users/:user/friends', ctx => {
    return ctx.user.getFriends().then(function(friends) {
      ctx.body = friends;
    });
  })
  // /users/3 => {"id": 3, "name": "Alex"}
  // /users/3/friends => [{"id": 4, "name": "TJ"}]

<a name="module_koa-router--Router.url"></a>

Router.url(path, params [, options]) ⇒ <code>String</code>

Generate URL from url pattern and given params.

Kind: static method of <code>Router</code>

Example

var url = Router.url('/users/:id', {id: 1});
// => "/users/1"

const url = Router.url('/users/:id', {id: 1}, {query: { active: true }});
// => "/users/1?active=true"

Contributing

Please submit all issues and pull requests to the alexmingoia/koa-router repository!

Tests

Run tests using npm test.

Support

If you have any problem or suggestion please open an issue here.