Move Routing into AD

1 files changed, 210 insertions, 0 deletions

diff --git a/actionpack/lib/action_controller/polymorphic_routes.rb b/actionpack/lib/action_controller/polymorphic_routes.rb
new file mode 100644
index 0000000000..2adf3575a7
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+++ b/actionpack/lib/action_controller/polymorphic_routes.rb
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+module ActionController
+  # Polymorphic URL helpers are methods for smart resolution to a named route call when
+  # given an Active Record model instance. They are to be used in combination with
+  # ActionController::Resources.
+  #
+  # These methods are useful when you want to generate correct URL or path to a RESTful
+  # resource without having to know the exact type of the record in question.
+  #
+  # Nested resources and/or namespaces are also supported, as illustrated in the example:
+  #
+  #   polymorphic_url([:admin, @article, @comment])
+  #
+  # results in:
+  #   
+  #   admin_article_comment_url(@article, @comment)
+  #
+  # == Usage within the framework
+  #
+  # Polymorphic URL helpers are used in a number of places throughout the Rails framework:
+  #
+  # * <tt>url_for</tt>, so you can use it with a record as the argument, e.g.
+  #   <tt>url_for(@article)</tt>;
+  # * ActionView::Helpers::FormHelper uses <tt>polymorphic_path</tt>, so you can write
+  #   <tt>form_for(@article)</tt> without having to specify <tt>:url</tt> parameter for the form
+  #   action;
+  # * <tt>redirect_to</tt> (which, in fact, uses <tt>url_for</tt>) so you can write
+  #   <tt>redirect_to(post)</tt> in your controllers;
+  # * ActionView::Helpers::AtomFeedHelper, so you don't have to explicitly specify URLs
+  #   for feed entries.
+  #
+  # == Prefixed polymorphic helpers
+  #
+  # In addition to <tt>polymorphic_url</tt> and <tt>polymorphic_path</tt> methods, a
+  # number of prefixed helpers are available as a shorthand to <tt>:action => "..."</tt>
+  # in options. Those are:
+  #
+  # * <tt>edit_polymorphic_url</tt>, <tt>edit_polymorphic_path</tt>
+  # * <tt>new_polymorphic_url</tt>, <tt>new_polymorphic_path</tt>
+  #
+  # Example usage:
+  #
+  #   edit_polymorphic_path(@post)              # => "/posts/1/edit"
+  #   polymorphic_path(@post, :format => :pdf)  # => "/posts/1.pdf"
+  module PolymorphicRoutes
+    # Constructs a call to a named RESTful route for the given record and returns the
+    # resulting URL string. For example:
+    #
+    #   # calls post_url(post)
+    #   polymorphic_url(post) # => "http://example.com/posts/1"
+    #   polymorphic_url([blog, post]) # => "http://example.com/blogs/1/posts/1"
+    #   polymorphic_url([:admin, blog, post]) # => "http://example.com/admin/blogs/1/posts/1"
+    #   polymorphic_url([user, :blog, post]) # => "http://example.com/users/1/blog/posts/1"
+    #   polymorphic_url(Comment) # => "http://example.com/comments"
+    #
+    # ==== Options
+    #
+    # * <tt>:action</tt> - Specifies the action prefix for the named route:
+    #   <tt>:new</tt> or <tt>:edit</tt>. Default is no prefix.
+    # * <tt>:routing_type</tt> - Allowed values are <tt>:path</tt> or <tt>:url</tt>.
+    #   Default is <tt>:url</tt>.
+    #
+    # ==== Examples
+    #
+    #   # an Article record
+    #   polymorphic_url(record)  # same as article_url(record)
+    #
+    #   # a Comment record
+    #   polymorphic_url(record)  # same as comment_url(record)
+    #
+    #   # it recognizes new records and maps to the collection
+    #   record = Comment.new
+    #   polymorphic_url(record)  # same as comments_url()
+    #
+    #   # the class of a record will also map to the collection
+    #   polymorphic_url(Comment) # same as comments_url()
+    #
+    def polymorphic_url(record_or_hash_or_array, options = {})
+      if record_or_hash_or_array.kind_of?(Array)
+        record_or_hash_or_array = record_or_hash_or_array.compact
+        record_or_hash_or_array = record_or_hash_or_array[0] if record_or_hash_or_array.size == 1
+      end
+
+      record    = extract_record(record_or_hash_or_array)
+      record    = record.to_model if record.respond_to?(:to_model)
+      namespace = extract_namespace(record_or_hash_or_array)
+
+      args = case record_or_hash_or_array
+        when Hash;  [ record_or_hash_or_array ]
+        when Array; record_or_hash_or_array.dup
+        else        [ record_or_hash_or_array ]
+      end
+
+      inflection = if options[:action].to_s == "new"
+        args.pop
+        :singular
+      elsif (record.respond_to?(:new_record?) && record.new_record?) ||
+            (record.respond_to?(:destroyed?) && record.destroyed?)
+        args.pop
+        :plural
+      elsif record.is_a?(Class)
+        args.pop
+        :plural
+      else
+        :singular
+      end
+
+      args.delete_if {|arg| arg.is_a?(Symbol) || arg.is_a?(String)}
+
+      named_route = build_named_route_call(record_or_hash_or_array, namespace, inflection, options)
+
+      url_options = options.except(:action, :routing_type)
+      unless url_options.empty?
+        args.last.kind_of?(Hash) ? args.last.merge!(url_options) : args << url_options
+      end
+
+      __send__(named_route, *args)
+    end
+
+    # Returns the path component of a URL for the given record. It uses
+    # <tt>polymorphic_url</tt> with <tt>:routing_type => :path</tt>.
+    def polymorphic_path(record_or_hash_or_array, options = {})
+      polymorphic_url(record_or_hash_or_array, options.merge(:routing_type => :path))
+    end
+
+    %w(edit new).each do |action|
+      module_eval <<-EOT, __FILE__, __LINE__
+        def #{action}_polymorphic_url(record_or_hash, options = {})         # def edit_polymorphic_url(record_or_hash, options = {})
+          polymorphic_url(                                                  #   polymorphic_url(
+            record_or_hash,                                                 #     record_or_hash,
+            options.merge(:action => "#{action}"))                          #     options.merge(:action => "edit"))
+        end                                                                 # end
+                                                                            #
+        def #{action}_polymorphic_path(record_or_hash, options = {})        # def edit_polymorphic_path(record_or_hash, options = {})
+          polymorphic_url(                                                  #   polymorphic_url(
+            record_or_hash,                                                 #     record_or_hash,
+            options.merge(:action => "#{action}", :routing_type => :path))  #     options.merge(:action => "edit", :routing_type => :path))
+        end                                                                 # end
+      EOT
+    end
+
+    def formatted_polymorphic_url(record_or_hash, options = {})
+      ActiveSupport::Deprecation.warn("formatted_polymorphic_url has been deprecated. Please pass :format to the polymorphic_url method instead", caller)
+      options[:format] = record_or_hash.pop if Array === record_or_hash
+      polymorphic_url(record_or_hash, options)
+    end
+
+    def formatted_polymorphic_path(record_or_hash, options = {})
+      ActiveSupport::Deprecation.warn("formatted_polymorphic_path has been deprecated. Please pass :format to the polymorphic_path method instead", caller)
+      options[:format] = record_or_hash.pop if record_or_hash === Array
+      polymorphic_url(record_or_hash, options.merge(:routing_type => :path))
+    end
+
+    private
+      def action_prefix(options)
+        options[:action] ? "#{options[:action]}_" : ''
+      end
+
+      def routing_type(options)
+        options[:routing_type] || :url
+      end
+
+      def build_named_route_call(records, namespace, inflection, options = {})
+        unless records.is_a?(Array)
+          record = extract_record(records)
+          route  = ''
+        else
+          record = records.pop
+          route = records.inject("") do |string, parent|
+            if parent.is_a?(Symbol) || parent.is_a?(String)
+              string << "#{parent}_"
+            else
+              string << "#{RecordIdentifier.__send__("plural_class_name", parent)}".singularize
+              string << "_"
+            end
+          end
+        end
+
+        if record.is_a?(Symbol) || record.is_a?(String)
+          route << "#{record}_"
+        else
+          route << "#{RecordIdentifier.__send__("plural_class_name", record)}"
+          route = route.singularize if inflection == :singular
+          route << "_"
+        end
+
+        action_prefix(options) + namespace + route + routing_type(options).to_s
+      end
+
+      def extract_record(record_or_hash_or_array)
+        case record_or_hash_or_array
+          when Array; record_or_hash_or_array.last
+          when Hash;  record_or_hash_or_array[:id]
+          else        record_or_hash_or_array
+        end
+      end
+
+      # Remove the first symbols from the array and return the url prefix
+      # implied by those symbols.
+      def extract_namespace(record_or_hash_or_array)
+        return "" unless record_or_hash_or_array.is_a?(Array)
+
+        namespace_keys = []
+        while (key = record_or_hash_or_array.first) && key.is_a?(String) || key.is_a?(Symbol)
+          namespace_keys << record_or_hash_or_array.shift
+        end
+
+        namespace_keys.map {|k| "#{k}_"}.join
+      end
+  end
+end