Bryan Ray
http://bryanray.net

The Merb Router
In Depth ...
Code Repository
https://github.com/merbday/atlanta
http://github.com/merbday/atlanta/tree/master/router

Thanks
Carl Lerche
Anyone else who has contributed to Merb ...

Simple Routes
Merb::Router.prepare do
# resources :articles
# RESTful routes
# resources :posts
end

Match 3 simple route
Merb::Router.prepare do
match(\"/signup\").
to(:controller => \"users\", :action => \"new\").
name(:signup)
end
Generating the route:
url(:signup) => /signup

Routes with variables
Merb::Router.prepare do
match(\"/articles/:year/:month/:day/:title\").
to(:controller => \"articles\", :action => \"show\").
name(:article)
end

Routes with variables
Generating
url(:article, :year => 2008, :month => 07, :day => 22,
:title => \"Awesomeness\")
# => /articles/2008/07/22/Awesomeness

Optional Path Segments
match('/articles(/:year(/:month(/:day)))/:title').
to(
:controller => :articles,
:action => \"with_optional_segments\").
name(:articles)
/articles/hello # => { :title => “hello” }
/articles/2008/12/hello
# => { :title => “hello”, :year => “2008”,
:month => “12” }

Routes with conditions
match(\"/articles\") do
with(:controller => \"articles\") do
match(\"/:title\", :title => /[a-z]+$/).
to(:action => \"with_title\")
match(\"/:id\", :id => /^[\\d]+$/).to(:action => \"with_id\")
end
end
/articles/hello # => Renders the #with_title action
/articles/12 # => Renders the #with_id action

The Subdomain Problem
The end goal
http://<account>.localhost:4000
http://bryan.localhost:4000
Matching inside the router
match(:account => 'bryan').
to(:controller => 'articles', :action => 'with_account')

The Subdomain Problem
module Merb
class Request
def account
subdomains(0).first
end
end
end

#url generation ...
url(:articles, :title => 'hello')
# => /articles/hello
url(:articles, :year => 2008, :title => 'hello')
# => /articles/2008/hello
url(:articles, :year => 2008, :month => 12, :title => 'hello')
# => /articles/2008/12/hello
url(:articles, :year => 2008, :month => 12, :day => 07, :title =>
'hello')
# => /articles/2008/12/7/hello
# Anonymous Parameters
url(:articles, 2008, 12, 07, :title => 'hello')
# => /articles/2008/12/7/testing

Default Routes
def default_routes(params = {}, &block)
match(\"/:controller(/:action(/:id))(.:format)\").
to(params, &block).name(:default)
end

Resource-ful Routes
Merb::Router.prepare do
# Resource-ful Routes
resources :articles
end
/articles GET => index
/articles POST => create
/articles/new GET => new
/articles/:id GET => show
/articles/:id PUT => update
/articles/:id DELETE => destroy
/articles/:id/edit GET => edit
/articles/:id/delete GET => delete

Nested Routes
resources :articles
resources :comments
end
Generating
link_to \"Article Comments\", url(:article_comments, 1)
# => /articles/1/comments

Multiple Nested Routes
resources :articles do
resources :comments
end
resources :songs do
resources :comments
end
resources :photos do
resources :comments
end

Generating the routes...
link_to \"view comment\",
comment.commentable.is_a?(Article) ? url(:article_comment,
comment.commentable.id, comment.id) :
comment.commentable.is_a?(Song) ? url(:song_comment,
comment.commentable.id, comment.id) : url(:photo_comment,
comment.commentable.id, comment.id)

Yea, right ...
link_to \"View Comment\", resource(comment.commentable, comment)
Much cleaner ...

More Resource examples
resource(@user)
vs.
url(:user, user)
resource(@user, :comments)
vs.
url(:user_comments, user)
resource(@user, @comment)
vs.
url(:user_comment, user, comment)

Friendly URLs
Route
resources :users, :identify => :name
Generating
resource(@user) # => /users/bryan

Can also use a block
identify(Article=>:permalink, User=>:login) do
resources :users do
resources :articles
end
end
Generating
resource(@user, @article)
# => /users/bryan/articles/hello-world

Redirecting legacy URLs
Legacy URL
/articles/123-hello-world
New URL
/articles/hello-world

In the Controller?
match(\"/articles/:id\").
to(:controller => \"articles\", :action => \"show\")

Use regex to match?
match(\"/articles/:id\", :id => /^\\d+-/).
to(:controller => \"articles\", :action => \"legacy\")
match(\"/articles/:url\").
to(:controller => \"articles\", :action => \"show\")

Or, add your own logic!
match(\"/articles/:url\").defer_to do |request, params|
if article = Article.first(:url => params[:url])
params.merge(:article => article)
elsif article = Article.first(:id => params[:url])
redirect url(:article, article.url)
else
false
end
end

Checking authentication
match(\"/secret\").defer_to do |request, params|
if request.session.authenticated?
params
end
end

Thanks!

Thanks!