Merb Plumbing
The Router

Who am I?

Some simple routes
Matching
Merb::Router.prepare do
match(\"/signup\").to(
:controller => \"users\", :action => \"new\"
).name(:signup)
end
Generating
url(:signup) => /signup

Routes with variables
Matching
match(\"/articles/:year/:month/:day/:title\").to(
:controller => \"articles\", :action => \"show\"
).name(:article)
Generating
url(:article, :year => 2008, :month => 07,
:day => 22, :title => \"Awesomeness\")
/articles/2008/07/22/Awesomeness

Routes with conditions
Matching
match(\"/articles\") do
with(:controller => \"articles\") do
match(\"/:title\", :title => /[a-z]+/).
to(:action => \"with_title\")
match(\"/:id\").to(:action => \"with_id\")
end
end
/articles/Hello_world => with_title
/articles/123 => with_id

More conditions
Matching
Merb::Router.prepare do
match(:domain => \"blogofawesomeness.com\") do
match(\"/the-daily-awesome\", :method => \"get\").
to(:articles)
# Any other route...
end
end

The subdomain problem
match(:subdomain => /(.*)/).
to(:account => \":subdomain[1]\") do
# application routes here...
end

Optional path segments
Matching
match(\"/articles(/:year(/:month(/:day)))/:title\").
to(:controller => \"articles\", :action => \"show\").
name(:article)
Generating
/articles/Hello => { :title => “Hello” }
/articles/2008/07/Hello
=> { :year => 2008, :month => “07”
:title => “Hello” }

... and generation still works!
url(:article, :title => \"Hello\")
url(:article, :year => \"2008\", :title => \"Hello\")
url(:article, :year => \"2008\", :month => \"07\",
:title => \"Hello\")
url(:article, :year => \"2008\", :month => \"07\",
:day => \"22\", :title => \"Hello\")

Getting Fancy
Matching
match(\"(:pref)/:file(.:format)\", :pref => \".*\").
to(:controller => \"cms\").name(:page)
/hi => { :file => “hi” }
/hi.xml => { :file => “hi”, :format => “xml”}
/path/to/hi => { :pref => “/path/to”, :file => “hi }

And you can still generate it
url(:page, :file => \"hi\")
/hi
url(:page, :pref => \"/path/to\", :file => \"hi\")
/path/to/hi
url(:page, :pref => \"/hello\", :file => \"world\",
:format => \"mp3\")
/hello/world.mp3

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

AWESOME!

Resource routes
Matching
resources :articles
/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

and you can nest them
Matching
resources :articles do
resources :comments
end
Generating
link_to \"view comment\", url(:article_comment,
comment.article_id, comment.id)

Nested multiple times
resources :articles do
resources :comments
end
resources :songs do
resources :comments
end
resources :photos do
resources :comments
end

and... generating?
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)
wha...?

Nah... how about this?
link_to \"view comment\",
resource(comment.commentable, comment)

Some more examples
resources :users do
resources :comments
end
Generating
resource(@user) resource(@user, :comments)
vs. vs.
url(:user, @user) url(:user_comments, @user)
resource @user, @comment
vs.
url(:user_comment, @user, @comment)

Oh yeah...
match(\"/:project\") do
resources :tasks
end
- While currently at /awesome/tasks
resource(@task)
=> /awesome/tasks/123
resource(@task, :project => \"woot\")
=> /woot/tasks/123

AWESOME!

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

It works as a block too
Matching
identify(Article=>:permalink, User=>:login) do
resources :users do
resources :articles
end
end
Generating
resource(@user, @article)
/users/carl/articles/hello-world

AWESOME!

Redirecting legacy URLs
Old: /articles/123-hello-world
New: /articles/Hello_world

Handle it in the controller?
match(\"/articles/:id\").
to(:controller => \"articles\", :action => \"show\")

Try to do it with Regexps?
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

Authentication works too
match(\"/secret\").defer_to do |request, params|
if request.session.authenticated?
params
end
end

Works great for plugins
def protect(&block)
protection = Proc.new do |request, params|
if request.session.authenticated?
params
else
redirect \"/login\"
end
end
defer(protection, &block)
end

Awesome!
protect.match(\"/admin\") do
# ... admin routes here
end

Thank you
(Awesome!)