vendor/rails/actionpack/lib/action_controller/polymorphic_routes.rb

   1 module ActionController
   2   # Polymorphic URL helpers are methods for smart resolution to a named route call when
   3   # given an Active Record model instance. They are to be used in combination with
   4   # ActionController::Resources.
   5   #
   6   # These methods are useful when you want to generate correct URL or path to a RESTful
   7   # resource without having to know the exact type of the record in question.
   8   #
   9   # Nested resources and/or namespaces are also supported, as illustrated in the example:
  10   #
  11   #   polymorphic_url([:admin, @article, @comment])
  12   #
  13   # results in:
  14   #
  15   #   admin_article_comment_url(@article, @comment)
  16   #
  17   # == Usage within the framework
  18   #
  19   # Polymorphic URL helpers are used in a number of places throughout the Rails framework:
  20   #
  21   # * <tt>url_for</tt>, so you can use it with a record as the argument, e.g.
  22   #   <tt>url_for(@article)</tt>;
  23   # * ActionView::Helpers::FormHelper uses <tt>polymorphic_path</tt>, so you can write
  24   #   <tt>form_for(@article)</tt> without having to specify <tt>:url</tt> parameter for the form
  25   #   action;
  26   # * <tt>redirect_to</tt> (which, in fact, uses <tt>url_for</tt>) so you can write
  27   #   <tt>redirect_to(post)</tt> in your controllers;
  28   # * ActionView::Helpers::AtomFeedHelper, so you don't have to explicitly specify URLs
  29   #   for feed entries.
  30   #
  31   # == Prefixed polymorphic helpers
  32   #
  33   # In addition to <tt>polymorphic_url</tt> and <tt>polymorphic_path</tt> methods, a
  34   # number of prefixed helpers are available as a shorthand to <tt>:action => "..."</tt>
  35   # in options. Those are:
  36   #
  37   # * <tt>edit_polymorphic_url</tt>, <tt>edit_polymorphic_path</tt>
  38   # * <tt>new_polymorphic_url</tt>, <tt>new_polymorphic_path</tt>
  39   #
  40   # Example usage:
  41   #
  42   #   edit_polymorphic_path(@post)              # => "/posts/1/edit"
  43   #   polymorphic_path(@post, :format => :pdf)  # => "/posts/1.pdf"
  44   module PolymorphicRoutes
  45     # Constructs a call to a named RESTful route for the given record and returns the
  46     # resulting URL string. For example:
  47     #
  48     #   # calls post_url(post)
  49     #   polymorphic_url(post) # => "http://example.com/posts/1"
  50     #   polymorphic_url([blog, post]) # => "http://example.com/blogs/1/posts/1"
  51     #   polymorphic_url([:admin, blog, post]) # => "http://example.com/admin/blogs/1/posts/1"
  52     #   polymorphic_url([user, :blog, post]) # => "http://example.com/users/1/blog/posts/1"
  53     #
  54     # ==== Options
  55     #
  56     # * <tt>:action</tt> - Specifies the action prefix for the named route:
  57     #   <tt>:new</tt> or <tt>:edit</tt>. Default is no prefix.
  58     # * <tt>:routing_type</tt> - Allowed values are <tt>:path</tt> or <tt>:url</tt>.
  59     #   Default is <tt>:url</tt>.
  60     #
  61     # ==== Examples
  62     #
  63     #   # an Article record
  64     #   polymorphic_url(record)  # same as article_url(record)
  65     #
  66     #   # a Comment record
  67     #   polymorphic_url(record)  # same as comment_url(record)
  68     #
  69     #   # it recognizes new records and maps to the collection
  70     #   record = Comment.new
  71     #   polymorphic_url(record)  # same as comments_url()
  72     #
  73     def polymorphic_url(record_or_hash_or_array, options = {})
  74       if record_or_hash_or_array.kind_of?(Array)
  75         record_or_hash_or_array = record_or_hash_or_array.compact
  76         record_or_hash_or_array = record_or_hash_or_array[0] if record_or_hash_or_array.size == 1
  77       end
  78
  79       record    = extract_record(record_or_hash_or_array)
  80       namespace = extract_namespace(record_or_hash_or_array)
  81
  82       args = case record_or_hash_or_array
  83         when Hash;  [ record_or_hash_or_array ]
  84         when Array; record_or_hash_or_array.dup
  85         else        [ record_or_hash_or_array ]
  86       end
  87
  88       inflection =
  89         case
  90         when options[:action].to_s == "new"
  91           args.pop
  92           :singular
  93         when record.respond_to?(:new_record?) && record.new_record?
  94           args.pop
  95           :plural
  96         else
  97           :singular
  98         end
  99
 100       args.delete_if {|arg| arg.is_a?(Symbol) || arg.is_a?(String)}
 101
 102       named_route = build_named_route_call(record_or_hash_or_array, namespace, inflection, options)
 103
 104       url_options = options.except(:action, :routing_type)
 105       unless url_options.empty?
 106         args.last.kind_of?(Hash) ? args.last.merge!(url_options) : args << url_options
 107       end
 108
 109       __send__(named_route, *args)
 110     end
 111
 112     # Returns the path component of a URL for the given record. It uses
 113     # <tt>polymorphic_url</tt> with <tt>:routing_type => :path</tt>.
 114     def polymorphic_path(record_or_hash_or_array, options = {})
 115       options[:routing_type] = :path
 116       polymorphic_url(record_or_hash_or_array, options)
 117     end
 118
 119     %w(edit new).each do |action|
 120       module_eval <<-EOT, __FILE__, __LINE__
 121         def #{action}_polymorphic_url(record_or_hash, options = {})         # def edit_polymorphic_url(record_or_hash, options = {})
 122           polymorphic_url(                                                  #   polymorphic_url(
 123             record_or_hash,                                                 #     record_or_hash,
 124             options.merge(:action => "#{action}"))                          #     options.merge(:action => "edit"))
 125         end                                                                 # end
 126                                                                             #
 127         def #{action}_polymorphic_path(record_or_hash, options = {})        # def edit_polymorphic_path(record_or_hash, options = {})
 128           polymorphic_url(                                                  #   polymorphic_url(
 129             record_or_hash,                                                 #     record_or_hash,
 130             options.merge(:action => "#{action}", :routing_type => :path))  #     options.merge(:action => "edit", :routing_type => :path))
 131         end                                                                 # end
 132       EOT
 133     end
 134
 135     def formatted_polymorphic_url(record_or_hash, options = {})
 136       ActiveSupport::Deprecation.warn("formatted_polymorphic_url has been deprecated. Please pass :format to the polymorphic_url method instead", caller)
 137       options[:format] = record_or_hash.pop if Array === record_or_hash
 138       polymorphic_url(record_or_hash, options)
 139     end
 140
 141     def formatted_polymorphic_path(record_or_hash, options = {})
 142       ActiveSupport::Deprecation.warn("formatted_polymorphic_path has been deprecated. Please pass :format to the polymorphic_path method instead", caller)
 143       options[:format] = record_or_hash.pop if record_or_hash === Array
 144       polymorphic_url(record_or_hash, options.merge(:routing_type => :path))
 145     end
 146
 147     private
 148       def action_prefix(options)
 149         options[:action] ? "#{options[:action]}_" : ''
 150       end
 151
 152       def routing_type(options)
 153         options[:routing_type] || :url
 154       end
 155
 156       def build_named_route_call(records, namespace, inflection, options = {})
 157         unless records.is_a?(Array)
 158           record = extract_record(records)
 159           route  = ''
 160         else
 161           record = records.pop
 162           route = records.inject("") do |string, parent|
 163             if parent.is_a?(Symbol) || parent.is_a?(String)
 164               string << "#{parent}_"
 165             else
 166               string << "#{RecordIdentifier.__send__("plural_class_name", parent)}".singularize
 167               string << "_"
 168             end
 169           end
 170         end
 171
 172         if record.is_a?(Symbol) || record.is_a?(String)
 173           route << "#{record}_"
 174         else
 175           route << "#{RecordIdentifier.__send__("plural_class_name", record)}"
 176           route = route.singularize if inflection == :singular
 177           route << "_"
 178         end
 179
 180         action_prefix(options) + namespace + route + routing_type(options).to_s
 181       end
 182
 183       def extract_record(record_or_hash_or_array)
 184         case record_or_hash_or_array
 185           when Array; record_or_hash_or_array.last
 186           when Hash;  record_or_hash_or_array[:id]
 187           else        record_or_hash_or_array
 188         end
 189       end
 190
 191       # Remove the first symbols from the array and return the url prefix
 192       # implied by those symbols.
 193       def extract_namespace(record_or_hash_or_array)
 194         return "" unless record_or_hash_or_array.is_a?(Array)
 195
 196         namespace_keys = []
 197         while (key = record_or_hash_or_array.first) && key.is_a?(String) || key.is_a?(Symbol)
 198           namespace_keys << record_or_hash_or_array.shift
 199         end
 200
 201         namespace_keys.map {|k| "#{k}_"}.join
 202       end
 203   end
 204 end