url_for
url_for(options = {})
public
Returns the URL for the set of options provided. This takes the same options as url_for in Action Controller (see the documentation for ActionController::Base#url_for). Note that by default :only_path is true so you’ll get the relative "/controller/action" instead of the fully qualified URL like "http://example.com/controller/action".
Options
- :anchor - Specifies the anchor name to be appended to the path.
- :only_path - If true, returns the relative URL (omitting the protocol, host name, and port) (true by default unless :host is specified).
- :trailing_slash - If true, adds a trailing slash, as in "/archive/2005/". Note that this is currently not recommended since it breaks caching.
- :host - Overrides the default (current) host if provided.
- :protocol - Overrides the default (current) protocol if provided.
- :user - Inline HTTP authentication (only plucked out if :password is also present).
- :password - Inline HTTP authentication (only plucked out if :user is also present).
Relying on named routes
If you instead of a hash pass a record (like an Active Record or Active Resource) as the options parameter, you’ll trigger the named route for that record. The lookup will happen on the name of the class. So passing a Workshop object will attempt to use the workshop_path route. If you have a nested route, such as admin_workshop_path you’ll have to call that explicitly (it’s impossible for url_for to guess that route).
Examples
<%= url_for(:action => 'index') %> # => /blog/ <%= url_for(:action => 'find', :controller => 'books') %> # => /books/find <%= url_for(:action => 'login', :controller => 'members', :only_path => false, :protocol => 'https') %> # => https://www.railsapplication.com/members/login/ <%= url_for(:action => 'play', :anchor => 'player') %> # => /messages/play/#player <%= url_for(:action => 'jump', :anchor => 'tax&ship') %> # => /testing/jump/#tax&ship <%= url_for(Workshop.new) %> # relies on Workshop answering a persisted? call (and in this case returning false) # => /workshops <%= url_for(@workshop) %> # calls @workshop.to_s # => /workshops/5 <%= url_for("http://www.example.com") %> # => http://www.example.com <%= url_for(:back) %> # if request.env["HTTP_REFERER"] is set to "http://www.example.com" # => http://www.example.com <%= url_for(:back) %> # if request.env["HTTP_REFERER"] is not set or is blank # => javascript:history.back()
Use the current URL, with changes
You can use the current URL, whatever it is, with changes, as in:
# Create a link to the current page in RSS form url_for(:overwrite_params => {:format => :rss})
This can be super-helpful because it preserves any GET params (like search parameters)
Using namespaces
If you are using a namespace in your routes.rb, for example:
namespace :admin do resources :products end
then you can:
url_for([:admin, @product])
and:
url_for([:edit, :admin, @product])
Specify :host option in emails
Emails need a fully qualified URL (with domain). Use the :host parameter.
But note also that you need to specify a value that is not dependent upon the request context. http://api.rubyonrails.org/classes/ActionMailer/Base.html recommends setting a default host in application.rb For those of us who have development, test, staging and production environments, set in the environment-specific files, or in the :default hash in the mailer.
This applies to both +url_for(:host => “example.com”)+ and when using named routes as in +widgets_url(:host => “example.com”)+