backbone.history.html5.coffee

# 
# Replaces Backbone.History with support for HTML5 history API if browser supports it.
# To use, setup your controllers as usual and try it with a browser that supports the HTML5 history API.
# For browsers that don't support the HTML5 API, this will fall back to using the default Backbone hash routing.
# 
# I have only tested this on my project in Firefox, Safari and Chrome so let me know.
# 
pushSupport = window.history? and window.history.pushState?
if pushSupport and Backbone? and Backbone.History?
	rootUrl = document.location.protocol+'//'+(document.location.host or document.location.hostname)
	_.extend Backbone.History.prototype,
		# Simply return the browser's whole path
		getFragment: ->
			return window.location.pathname.substring(1)
	
		# Set all hrefs to be saved in the browser history and then routed through your controllers.
		# Handy for single page apps with no server side templating.
		# You can remove this and the call to it in start if you don't want it.
		# In that case, call Backbone.history.saveLocation and Backbone.history.loadUrl directly
		ajaxifyInternalLinks: ->
			self = this
			$('a[href^=/]').live 'click', (event) ->
				href = $(this).attr('href')
				self.saveLocation(href)
				self.loadUrl(href.substring(1))
				event.preventDefault()
				return false
		
		# Overwriting this function basically replaces Backbone's history mechanism with everything in this module.			
		start: ->
			_.bindAll(this, 'loadUrl')
			
			# Remove this call if you don't all links to be routed through your controller automatically,
			@ajaxifyInternalLinks()
			
			# Route the initial browser url from page load
			@loadUrl()

			# Handle history navigation, such as browser back/forward clicks by listening for popstate
			# We don't use JQuery event binding here because the popstate event isn't passed properly.
			# If there is no event.state then it must be a page load event, ignore it.
			self = this
			window.onpopstate = (event) -> if event.state? then self.loadUrl()
		
		# This has been modified to allow the fragment to be passed in directly.
		# If fragment is not passed it will be loaded from getFragment as usual.
		loadUrl: (fragment) ->
			# Such a nice assignment/check in CoffeeScript...
			fragment = @fragment = fragment ? @getFragment()
			# We skip all the other stuff Backbone does for hashes and go straight to the routes
			_.each @handlers, (handler) ->
				if handler.route.test(fragment) then handler.callback(fragment)	
		
		# This has been modified to allow the browser history to be replaced by passing true for replace.
		# This is handy for times you need to patch the history from inside the controller routes or somewhere
		# else in your app.
		saveLocation: (fragment, replace) ->
			return if not fragment?
			return if @fragment is fragment
			@fragment = fragment
			loc = window.location
			url = loc.protocol + "//" + loc.host + fragment
			state = {ts: new Date()}
			if replace? then window.history.replaceState(state, document.title, url)
			else window.history.pushState(state, document.title, url)