Director is a router. Routing is the process of determining what code to run when a URL is requested.
A routing library that works in both the browser and node.js environments with as few differences as possible. Simplifies the development of Single Page Apps and Node.js applications. Dependency free (doesn't require jQuery or Express, etc).
It simply watches the hash of the URL to determine what to do, for example:
http://foo.com/#/bar
Client-side routing (aka hash-routing) allows you to specify some information about the state of the application using the URL. So that when the user visits a specific URL, the application can be transformed accordingly.
Here is a simple example:
<!html>
<html>
<head>
<script src="/director.js"></script>
<script>
var author = function () { /* ... */ },
books = function () { /* ... */ },
viewBook = function(bookId) { /* bookId is populated. */ };
var routes = {
'/author': author,
'/books': [books, function() { /* An inline route handler. */ }],
'/books/view/:bookId': viewBook
};
var router = Router(routes);
router.init();
</script>
</head>
<body>
</body>
</html>
Director works great with your favorite DOM library, such as jQuery.
<!html>
<html>
<head>
<script src="/director.js"></script>
<script>
//
// create some functions to be executed when
// the correct route is issued by the user.
//
var author = function () { /* ... */ },
books = function () { /* ... */ },
allroutes = function(route) {
var sections = $('section');
sections.hide();
sections.find('data-route[' + route + ']').show();
};
//
// define the routing table.
//
var routes = {
'/author': showAuthorInfo,
'/books': [showAuthorInfo, listBooks]
};
//
// instantiate the router.
//
var router = Router(routes);
//
// a global configuration setting.
//
router.configure({
on: allroutes
});
router.init();
</script>
</head>
<body>
<section data-route="author">Author Name</section>
<section data-route="books">Book1, Book2, Book3</section>
</body>
</html>
You can find a browser-specific build of director
here which has all of the server code stripped away.
Director handles routing for HTTP requests similar to journey
or express
:
//
// require the native http module, as well as director.
//
var http = require('http'),
director = require('director');
//
// create some logic to be routed to.
//
function helloWorld(route) {
this.res.writeHead(200, { 'Content-Type': 'text/plain' })
this.res.end('hello world from (' + route + ')');
}
//
// define a routing table.
//
var router = new director.http.Router({
'/hello': {
get: helloWorld
}
});
//
// setup a server and when there is a request, dispatch the
// route that was requestd in the request object.
//
var server = http.createServer(function (req, res) {
router.dispatch(req, res, function (err) {
if (err) {
res.writeHead(404);
res.end();
}
});
});
//
// You can also do ad-hoc routing, similar to `journey` or `express`.
// This can be done with a string or a regexp.
//
router.get('/bonjour', helloWorld);
router.get(/hola/, helloWorld);
//
// set the server to listen on port `8080`.
//
server.listen(8080);
Director supports Command Line Interface routing. Routes for cli options are based on command line input (i.e. process.argv
) instead of a URL.
var director = require('director');
var router = new director.cli.Router();
router.on('create', function () {
console.log('create something');
});
router.on(/destroy/, function () {
console.log('destroy something');
});
// You will need to dispatch the cli arguments yourself
router.dispatch('on', process.argv.slice(2).join(' '));
Using the cli router, you can dispatch commands by passing them as a string. For example, if this example is in a file called foo.js
:
$ node foo.js create
create something
$ node foo.js destroy
destroy something
- Constructor
- Routing Table
- Adhoc Routing
- Scoped Routing
- Routing Events
- Configuration
- URL Matching
- URL Params
- Route Recursion
- Async Routing
- Resources
- Instance Methods
var router = Router(routes);
An object literal that contains nested route definitions. A potentially nested set of key/value pairs. The keys in the object literal represent each potential part of the URL. The values in the object literal contain references to the functions that should be associated with them. bark and meow are two functions that you have defined in your code.
//
// Assign routes to an object literal.
//
var routes = {
//
// a route which assigns the function `bark`.
//
'/dog': bark,
//
// a route which assigns the functions `meow` and `scratch`.
//
'/cat': [meow, scratch]
};
//
// Instantiate the router.
//
var router = Router(routes);
When developing large client-side or server-side applications it is not always possible to define routes in one location. Usually individual decoupled components register their own routes with the application router. We refer to this as Adhoc Routing. Lets take a look at the API director
exposes for adhoc routing:
Client-side Routing
var router = new Router().init();
router.on('/some/resource', function () {
//
// Do something on `/#/some/resource`
//
});
HTTP Routing
var router = new director.http.Router();
router.get(/\/some\/resource/, function () {
//
// Do something on an GET to `/some/resource`
//
});
In large web appliations, both Client-side and Server-side, routes are often scoped within a few individual resources. Director exposes a simple way to do this for Adhoc Routing scenarios:
var router = new director.http.Router();
//
// Create routes inside the `/users` scope.
//
router.path(/\/users\/(\w+)/, function () {
//
// The `this` context of the function passed to `.path()`
// is the Router itself.
//
this.post(function (id) {
//
// Create the user with the specified `id`.
//
});
this.get(function (id) {
//
// Retreive the user with the specified `id`.
//
});
this.get(/\/friends/, function (id) {
//
// Get the friends for the user with the specified `id`.
//
});
});
In director
, a "routing event" is a named property in the Routing Table which can be assigned to a function or an Array of functions to be called when a route is matched in a call to router.dispatch()
.
- on: A function or Array of functions to execute when the route is matched.
- before: A function or Array of functions to execute before calling the
on
method(s).
Client-side only
- after: A function or Array of functions to execute when leaving a particular route.
- once: A function or Array of functions to execute only once for a particular route.
Given the flexible nature of director
there are several options available for both the Client-side and Server-side. These options can be set using the .configure()
method:
var router = new director.Router(routes).configure(options);
The options
are:
- recurse: Controls route recursion. Use
forward
,backward
, orfalse
. Default isfalse
Client-side, andbackward
Server-side. - strict: If set to
false
, then trailing slashes (or other delimiters) are allowed in routes. Default istrue
. - async: Controls async routing. Use
true
orfalse
. Default isfalse
. - delimiter: Character separator between route fragments. Default is
/
. - notfound: A function to call if no route is found on a call to
router.dispatch()
. - on: A function (or list of functions) to call on every call to
router.dispatch()
when a route is found. - before: A function (or list of functions) to call before every call to
router.dispatch()
when a route is found.
Client-side only
- resource: An object to which string-based routes will be bound. This can be especially useful for late-binding to route functions (such as async client-side requires).
- after: A function (or list of functions) to call when a given route is no longer the active route.
var router = Router({
//
// given the route '/dog/yella'.
//
'/dog': {
'/:color': {
//
// this function will return the value 'yella'.
//
on: function (color) { console.log(color) }
}
}
});
Routes can sometimes become very complex, simple/:tokens
don't always suffice. Director supports regular expressions inside the route names. The values captured from the regular expressions are passed to your listener function.
var router = Router({
//
// given the route '/hello/world'.
//
'/hello': {
'/(\\w+)': {
//
// this function will return the value 'world'.
//
on: function (who) { console.log(who) }
}
}
});
var router = Router({
//
// given the route '/hello/world/johny/appleseed'.
//
'/hello': {
'/world/?([^\/]*)\/([^\/]*)/?': function (a, b) {
console.log(a, b);
}
}
});
When you are using the same route fragments it is more descriptive to define these fragments by name and then use them in your Routing Table or Adhoc Routes. Consider a simple example where a userId
is used repeatedly.
//
// Create a router. This could also be director.cli.Router() or
// director.http.Router().
//
var router = new director.Router();
//
// A route could be defined using the `userId` explicitly.
//
router.on(/([\w-_]+)/, function (userId) { });
//
// Define a shorthand for this fragment called `userId`.
//
router.param('userId', /([\\w\\-]+)/);
//
// Now multiple routes can be defined with the same
// regular expression.
//
router.on('/anything/:userId', function (userId) { });
router.on('/something-else/:userId', function (userId) { });
Can be assigned the value of forward
or backward
. The recurse option will determine the order in which to fire the listeners that are associated with your routes. If this option is NOT specified or set to null, then only the listeners associated with an exact match will be fired.
var routes = {
'/dog': {
'/angry': {
//
// Only this method will be fired.
//
on: growl
},
on: bark
}
};
var router = Router(routes);
var routes = {
'/dog': {
'/angry': {
//
// This method will be fired first.
//
on: growl
},
//
// This method will be fired second.
//
on: bark
}
};
var router = Router(routes).configure({ recurse: 'backward' });
var routes = {
'/dog': {
'/angry': {
//
// This method will be fired second.
//
on: growl
},
//
// This method will be fired first.
//
on: bark
}
};
var router = Router(routes).configure({ recurse: 'forward' });
var routes = {
'/dog': {
'/angry': {
//
// This method will be fired first.
//
on: function() { return false; }
},
//
// This method will not be fired.
//
on: bark
}
};
//
// This feature works in reverse with recursion set to true.
//
var router = Router(routes).configure({ recurse: 'backward' });
Before diving into how Director exposes async routing, you should understand Route Recursion. At it's core route recursion is about evaluating a series of functions gathered when traversing the Routing Table.
Normally this series of functions is evaluated synchronously. In async routing, these functions are evaluated asynchronously. Async routing can be extremely useful both on the client-side and the server-side:
- Client-side: To ensure an animation or other async operations (such as HTTP requests for authentication) have completed before continuing evaluation of a route.
- Server-side: To ensure arbitrary async operations (such as performing authentication) have completed before continuing the evaluation of a route.
The method signatures for route functions in synchronous and asynchronous evaluation are different: async route functions take an additional next()
callback.
var router = new director.Router();
router.on('/:foo/:bar/:bazz', function (foo, bar, bazz) {
//
// Do something asynchronous with `foo`, `bar`, and `bazz`.
//
});
var router = new director.http.Router().configure({ async: true });
router.on('/:foo/:bar/:bazz', function (foo, bar, bazz, next) {
//
// Go do something async, and determine that routing should stop
//
next(false);
});
Available on the Client-side only. An object literal containing functions. If a host object is specified, your route definitions can provide string literals that represent the function names inside the host object. A host object can provide the means for better encapsulation and design.
var router = Router({
'/hello': {
'/usa': 'americas',
'/china': 'asia'
}
}).configure({ resource: container }).init();
var container = {
americas: function() { return true; },
china: function() { return true; }
};
options
{Object}: Options to configure this instance with.
Configures the Router instance with the specified options
. See Configuration for more documentation.
- token {string}: Named parameter token to set to the specified
matcher
- matcher {string|Regexp}: Matcher for the specified
token
.
Adds a route fragment for the given string token
to the specified regex matcher
to this Router instance. See URL Parameters for more documentation.
method
{string}: Method to insert within the Routing Table (e.g.on
,get
, etc.).path
{string}: Path within the Routing Table to set theroute
to.route
{function|Array}: Route handler to invoke for themethod
andpath
.
Adds the route
handler for the specified method
and path
within the Routing Table.
path
{string|Regexp}: Scope within the Routing Table to invoke theroutesFn
within.routesFn
{function}: Adhoc Routing function with calls tothis.on()
,this.get()
etc.
Invokes the routesFn
within the scope of the specified path
for this Router instance.
- method {string}: Method to invoke handlers for within the Routing Table
- path {string}: Path within the Routing Table to match
- callback {function}: Invoked once all route handlers have been called.
Dispatches the route handlers matched within the Routing Table for this instance for the specified method
and path
.
- routes {object}: Partial routing table to insert into this instance.
- path {string|Regexp}: Path within the Routing Table to insert the
routes
into.
Inserts the partial Routing Table, routes
, into the Routing Table for this Router instance at the specified path
.
Initialize the router, start listening for changes to the URL.
Returns the state object that is relative to the current route.
index
{Number}: The hash value is divided by forward slashes, each section then has an index, if this is provided, only that section of the route will be returned.
Returns the entire route or just a section of it.
route
{String}: Supply a route value, such ashome/stats
.
Set the current route.
start
{Number} - The position at which to start removing items.length
{Number} - The number of items to remove from the route.
Remove a segment from the current route.
index
{Number} - The hash value is divided by forward slashes, each section then has an index.value
{String} - The new value to assign the the position indicated by the first parameter.
Set a segment of the current route.
Is using a Client-side router a problem for SEO? Yes. If advertising is a requirement, you are probably building a "Web Page" and not a "Web Application". Director on the client is meant for script-heavy Web Applications.
Director is known to be Ender.js compatible. However, the project still needs solid cross-browser testing.
(The MIT License)
Copyright (c) 2010 Nodejitsu Inc. http://www.twitter.com/nodejitsu
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