Use this to wrap view elements that the user can‘t access. !! Note: this is an interface, not security feature !! You need to do all access control at the controller level.

Example: <%= if_authorized?(:index, User) do link_to(‘List all users’, users_path) end %> | <%= if_authorized?(:edit, @user) do link_to(‘Edit this user’, edit_user_path) end %> | <%= if_authorized?(:destroy, @user) do link_to ‘Destroy’, @user, :confirm => ‘Are you sure?’, :method => :delete end %>

[Source]

    # File app/helpers/users_helper.rb, line 14
14:   def if_authorized?(action, resource, &block)
15:     if authorized?(action, resource)
16:       yield action, resource
17:     end
18:   end

Link to the current user‘s page (using link_to_user) or to the login page (using link_to_login_with_IP).

[Source]

    # File app/helpers/users_helper.rb, line 82
82:   def link_to_current_user(options={})
83:     if current_user
84:       link_to_user current_user, options
85:     else
86:       content_text = options.delete(:content_text) || 'not signed in'
87:       # kill ignored options from link_to_user
88:       [:content_method, :title_method].each{|opt| options.delete(opt)} 
89:       link_to_login_with_IP content_text, options
90:     end
91:   end

Link to login page using remote ip address as link content

The :title (and thus, tooltip) is set to the IP address

Examples:

  link_to_login_with_IP
  # => <a href="/login" title="169.69.69.69">169.69.69.69</a>

  link_to_login_with_IP :content_text => 'not signed in'
  # => <a href="/login" title="169.69.69.69">not signed in</a>

[Source]

    # File app/helpers/users_helper.rb, line 67
67:   def link_to_login_with_IP(content_text=nil, options={})
68:     ip_addr           = request.remote_ip
69:     content_text    ||= ip_addr
70:     options.reverse_merge! :title => ip_addr
71:     if tag = options.delete(:tag)
72:       content_tag tag, h(content_text), options
73:     else
74:       link_to h(content_text), login_path, options
75:     end
76:   end

Link to user‘s page (‘users/1’)

By default, their login is used as link text and link title (tooltip)

Takes options

• :content_text => ‘Content text in place of user.login’, escaped with the standard h() function.
• :content_method => :user_instance_method_to_call_for_content_text
• :title_method => :user_instance_method_to_call_for_title_attribute
• as well as link_to()’s standard options

Examples:

  link_to_user @user
  # => <a href="/users/3" title="barmy">barmy</a>

  # if you've added a .name attribute:
 content_tag :span, :class => :vcard do
   (link_to_user user, :class => 'fn n', :title_method => :login, :content_method => :name) +
         ': ' + (content_tag :span, user.email, :class => 'email')
  end
  # => <span class="vcard"><a href="/users/3" title="barmy" class="fn n">Cyril Fotheringay-Phipps</a>: <span class="email">barmy@blandings.com</span></span>

  link_to_user @user, :content_text => 'Your user page'
  # => <a href="/users/3" title="barmy" class="nickname">Your user page</a>

[Source]

    # File app/helpers/users_helper.rb, line 46
46:   def link_to_user(user, options={})
47:     raise "Invalid user" unless user
48:     options.reverse_merge! :content_method => :login, :title_method => :login, :class => :nickname
49:     content_text      = options.delete(:content_text)
50:     content_text    ||= user.send(options.delete(:content_method))
51:     options[:title] ||= user.send(options.delete(:title_method))
52:     link_to h(content_text), user_path(user), options
53:   end