route

@page Routing Routing @parent Tutorial 8

can.route is the core of CanJS's routing functionality. It is a special Observe that updates window.location.hash when its properties change and updates its properties when window.location.hash changes. You can give can.route a template to translate URLs into property values, but if no route is provided, it just serializes the route into standard URL-encoded notation.

Here is how you might use can.route without a template:

@codestart // Before we start, empty the hash. window.location.hash = '';

// This means that can.route is empty. can.route.attr(); // {}

// Set the hash... window.location.hash = '#!id=7'; // ...and can.route reflects that. can.route.attr(); // {id: 7}

// Set the route... can.route.attr({type: 'todos'}, true); // ...and the hash reflects that. window.location.hash; // #!type=todos

// Set a new property on the route... can.route.attr('id', 6); // ...and the has changes again to reflect multiple properties. window.location.hash; // #!type=todos&id=6 @codeend

If you give can.route a template, you can make pretty URLs:

@codestart // Give can.route a template. can.route(':type/:id');

// If you set a hash that looks like the route... window.location.hash = '#!todos/5'; // ... the route data changes accordingly. can.route.attr(); // {type: 'todos', id: 5}

// If the route data is changed... can.route.attr({type: 'users', id: 29}); // ...the hash is changed using the template. window.location.hash; // '#!users/29'

// You can also supply defaults for routes. can.route('', {type: 'recipe'});

// Then if you change the hash... window.location.hash = ''; // ...the route data reflects the defaults. can.route.attr(); // {type: 'recipe'} @codeend

Listening to events

Because can.route is an Observe, you can bind to it just like normal Observes:

@codestart can.route.bind('id', function(ev, newVal, oldVal) { console.log('The hash's id changed.'); }); @codeend

You can listen to routing events in Controls with the route event:

@codestart var Routing = can.Control({ 'route': function() { // Matches every routing change, but gets passed no data. }, 'todos/:id route': function(data) { // Matches routes like #!todos/5, // and will get passed {id: 5} as data. }, ':type/:id route': function(data) { // Matches routes like #!recipes/5, // and will get passed {id: 5, type: 'recipes'} as data. }, }) @codeend

Making URLs and links

can.route.url takes a set of properties and makes a URL according to can.route's current route.

@codestart can.route(':type/:id', {type: 'todos'}); can.route.url({id: 7}); // #!todos/7 @codeend

can.route.link does the same thing as can.route.url, but it returns an anchor element (in string form) ready to be inserted into HTML. You can also specify extra propertires to be set on the element.

@codestart var a = can.route.link( 'Todo 5', {id: 7}, {className: 'button'} );

a; // <a href="#!todos/7" class="button">Todo 5</a> @codeend