polymorphic_routes.rb in radiant-0.7.0

- old
+ new

@@ -1,36 +1,117 @@
 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>
+  # * <tt>formatted_polymorphic_url</tt>, <tt>formatted_polymorphic_path</tt>
+  #
+  # Example usage:
+  #
+  #   edit_polymorphic_path(@post)              # => "/posts/1/edit"
+  #   formatted_polymorphic_path([@post, :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"
+    #
+    # ==== Options
+    #
+    # * <tt>:action</tt> - Specifies the action prefix for the named route:
+    #   <tt>:new</tt>, <tt>:edit</tt>, or <tt>:formatted</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()
+    #
     def polymorphic_url(record_or_hash_or_array, options = {})
-      record = extract_record(record_or_hash_or_array)
+      if record_or_hash_or_array.kind_of?(Array)
+        record_or_hash_or_array = record_or_hash_or_array.dup
+      end
 
+      record    = extract_record(record_or_hash_or_array)
+      format    = extract_format(record_or_hash_or_array, options)
       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 =
         case
-        when options[:action] == "new"
+        when options[:action].to_s == "new"
           args.pop
           :singular
         when record.respond_to?(:new_record?) && record.new_record?
           args.pop
           :plural
         else
           :singular
         end
+
+      args.delete_if {|arg| arg.is_a?(Symbol) || arg.is_a?(String)}
+      args << format if format
       
       named_route = build_named_route_call(record_or_hash_or_array, namespace, inflection, options)
       send!(named_route, *args)
     end
 
-    def polymorphic_path(record_or_hash_or_array)
-      polymorphic_url(record_or_hash_or_array, :routing_type => :path)
+    # 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 = {})
+      options[:routing_type] = :path
+      polymorphic_url(record_or_hash_or_array, options)
     end
 
     %w(edit new formatted).each do |action|
       module_eval <<-EOT, __FILE__, __LINE__
         def #{action}_polymorphic_url(record_or_hash)
@@ -41,48 +122,70 @@
           polymorphic_url(record_or_hash, :action => "#{action}", :routing_type => :path)
         end
       EOT
     end
 
-
     private
       def action_prefix(options)
         options[:action] ? "#{options[:action]}_" : ""
       end
 
       def routing_type(options)
-        "#{options[:routing_type] || "url"}"
+        options[:routing_type] || :url
       end
 
       def build_named_route_call(records, namespace, inflection, options = {})
-        records = Array.new([extract_record(records)]) unless records.is_a?(Array)        
-        base_segment = "#{RecordIdentifier.send!("#{inflection}_class_name", records.pop)}_"
+        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!("singular_class_name", parent)}_"
+            end
+          end
+        end
 
-        method_root = records.reverse.inject(base_segment) do |string, name|
-          segment = "#{RecordIdentifier.send!("singular_class_name", name)}_"
-          segment << string
+        if record.is_a?(Symbol) || record.is_a?(String)
+          route << "#{record}_"
+        else
+          route << "#{RecordIdentifier.send!("#{inflection}_class_name", record)}_"
         end
 
-        action_prefix(options) + namespace + method_root + routing_type(options)
+        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
       
+      def extract_format(record_or_hash_or_array, options)
+        if options[:action].to_s == "formatted" && record_or_hash_or_array.is_a?(Array)
+          record_or_hash_or_array.pop
+        elsif options[:format]
+          options[:format]
+        else
+          nil
+        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)
-        returning "" do |namespace|
-          if record_or_hash_or_array.is_a?(Array)
-            record_or_hash_or_array.delete_if do |record_or_namespace|
-              if record_or_namespace.is_a?(String) || record_or_namespace.is_a?(Symbol)
-                namespace << "#{record_or_namespace.to_s}_"
-              end
-            end
-          end  
+        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