Router

Tiny es2015 JavaScript Router with named parameters, HTML5 pushState and express-like middleware support.

Why Another Router

I needed/wanted a small client-size router for use in an es2015 app. I found Grapnel. It had all the features but had 2 drawbacks. It attempts to be both a client and server router. And it doesn't load in an es2015 app using an import statement. So I rewrote it as an esnext-router.

Download/Installation

Install with npm

npm install esnext-router

Or by using jspm:

jspm install esnext-router

esnext-router Features

• Supports routing using pushState
• Supports Named Parameters similar to Sinatra, Restify, and Express
• Middleware Support
• Works on the client or server-side
• RegExp Support
• Unobtrusive, supports multiple routers on the same page
• No dependencies

Basic Router

import Router from 'esnext-router';
const router = new Router();

router.add('products/:category/:id?', function(req){
    const id = req.params.id,
        category = req.params.category;
    // GET http://mysite.com/#products/widgets/134
    console.log(category, id);
    // => widgets 134
});

Named Parameters

esnext-router supports regex style routes similar to Sinatra, Restify, and Express. The properties are mapped to the parameters in the request.

router.add('products/:id?', function(req){
  // GET /file.html#products/134
  req.params.id
  // => 134
});

router.add('products/*', function(req){
    // The wildcard/asterisk will match anything after that point in the URL
    // Parameters are provided req.params using req.params[n], where n is the nth capture
});

Middleware Support

esnext-router also supports middleware:

const auth = function(req, event, next){
  user.auth(function(err){
      req.user = this;
      next();
  });
}

router.add('/*', auth, function(req){
  console.log(req.user);
});

Route Context

You can add context to a route and even use it with middleware:

const usersRoute = router.context('/user/:id', getUser, getFollowers); // Middleware can be used here

usersRoute('/', function(req, event){
  console.log('Profile', req.params.id);
});

usersRoute('/followers', otherMiddleware, function(req, event){ // Middleware can be used here too
  console.log('Followers', req.params.id);
});

router.navigate('/user/13589');
// => Profile 13589

router.navigate('/user/13589/followers');
// => Followers 13589

Declaring Multiple Routes

const routes = {
  'products' : function(req){
      // GET /file.html#products
  },
  'products/:category/:id?' : function(req){
      // GET /file.html#products/widgets/35
      req.params.category
      // => widgets
  }
}

Event Handling

import Router from 'esnext-router';
const router = new Router();

router.on('navigate', function(event){
  // GET /foo/bar
  console.log('URL changed to %s', this.path());
  // => URL changed to /foo/bar
});

RegExp Support

esnext-router allows RegEx when defining a route:

import Router from 'esnext-router';
const expression = /^food\/tacos\/(.*)$/i;
const router = new Router();

router.add(expression, function(req, event){
  // GET http://mysite.com/page#food/tacos/good
  console.log('I think tacos are %s.', req.params[0]);
  // => "He thinks tacos are good."
});

Enabling PushState

pushState is the default.

You can also specify a root URL by setting it as an option:

const router = new Router({ root : '/public/search/', pushState : true });

The root may require a beginning slash and a trailing slash depending on how your application utilizes the router.

Middleware

esnext-router uses middleware similar to how Express uses middleware. Middleware has access to the req object, event object, and the next middleware in the call stack (commonly denoted as next). Middleware must call next() to pass control to the next middleware, otherwise the router will stop.

For more information about how middleware works, see Using Middleware.

const user = function(req, event, next){
  user.add(function(err){
      req.user = this;
      next();
  });
}

router.add('/user/*', user, function(req){
  console.log(req.user);
});

Navigation

You can navigate through your application with router.navigate:

router.navigate('/products/123');

Stopping a Route Event

router.on('match', function(event){
  event.preventDefault(); // Stops event handler
});

Stopping Event Propagation

router.add('/products/:id', function(req, event){
  event.stopPropagation(); // Stops propagation of the event
});

router.add('/products/widgets', function(req, event){
  // This will not be executed
});

router.navigate('/products/widgets');

404 Pages

You can specify a route that only uses a wildcard * as your final route, then use event.parent() which returns false if the call stack doesn't have any other routes to run.

const routes = {
  '/' : function(req, e){
    // Handle route
  },
  '/store/products/:id' : function(req, e){
    // Handle route
  },
  '/category/:id' : function(req, e){
      // Handle route
  },
  '/*' : function(req, e){
    if(!e.parent()){
        // Handle 404
    }
  }
}

API Documentation

get Adds a listeners and middleware for routes

/**
 * @param {String|RegExp} path
 * @param {Function} [[middleware], callback]
*/
router.add('/store/:category/:id?', function(req, event){
    const category = req.params.category,
        id = req.params.id;

    console.log('Product #%s in %s', id, category);
});

navigate Navigate through application

/**
 * @param {String} path relative to root
*/
router.navigate('/products/123');

on Adds a new event listener

/**
 * @param {String} event name (multiple events can be called when separated by a space " ")
 * @param {Function} callback
*/
router.on('myevent', function(event){
    console.log('router works!');
});

once A version of on except its handler will only be called once

/**
 * @param {String} event name (multiple events can be called when separated by a space " ")
 * @param {Function} callback
*/
router.once('init', function(){
    console.log('This will only be executed once');
});

trigger Triggers an event

/**
 * @param {String} event name
 * @param {Mixed} [attributes] Parameters that will be applied to event handler
*/
router.trigger('event', eventArg1, eventArg2, etc);

context Returns a function that can be called with a specific route in context.

Both the router.context method and the function it returns can accept middleware. Note: when calling route.context, you should omit the trailing slash.

/**
 * @param {String} Route context (without trailing slash)
 * @param {[Function]} Middleware (optional)
 * @return {Function} Adds route to context
*/
const usersRoute = router.context('/user/:id');

usersRoute('/followers', function(req, event){
    console.log('Followers', req.params.id);
});

router.navigate('/user/13589/followers');
// => Followers 13589

path

• router.path('string') Sets a new path or hash
• router.path() Gets path or hash
• router.path(false) Clears the path or hash

bind An alias of on

add An alias of get

fragment (Deprecated)

Options

• root Root of your app, all navigation will be relative to this

Events

• navigate Fires when router navigates through history
• match Fires when a new match is found, but before the handler is called
• hashchange Fires when hashtag is changed

License

MIT License