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 17
17:   def if_authorized?(action, resource, &block)
18:     if authorized?(action, resource)
19:       yield action, resource
20:     end
21:   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 85
85:   def link_to_current_user(options={})
86:     if current_user
87:       link_to_user current_user, options
88:     else
89:       content_text = options.delete(:content_text) || 'not signed in'
90:       # kill ignored options from link_to_user
91:       [:content_method, :title_method].each{|opt| options.delete(opt)} 
92:       link_to_login_with_IP content_text, options
93:     end
94:   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 70
70:   def link_to_login_with_ip content_text=nil, options={}
71:     ip_addr           = request.remote_ip
72:     content_text    ||= ip_addr
73:     options.reverse_merge! :title => ip_addr
74:     if tag = options.delete(:tag)
75:       content_tag tag, h(content_text), options
76:     else
77:       link_to h(content_text), login_path, options
78:     end
79:   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 49
49:   def link_to_user(user, options={})
50:     raise "Invalid user" unless user
51:     options.reverse_merge! :content_method => :login, :title_method => :login, :class => :nickname
52:     content_text      = options.delete(:content_text)
53:     content_text    ||= user.send(options.delete(:content_method))
54:     options[:title] ||= user.send(options.delete(:title_method))
55:     link_to h(content_text), user_path(user), options
56:   end