moving all building code to Cell::Building for better overrideability.

lib/cell.rb

@@ -1,6 +1,6 @@
 module Cell
   autoload :Caching, 'cell/caching'
-
+  
   extend ActiveSupport::Concern
 
   DEFAULT_VIEW_PATHS = [File.join('app', 'cells')]
@@ -18,63 +18,5 @@ def render_cell_for(controller, name, state, *args)
 
       cell.render_state(state, *args)
     end
-
-    # Creates a cell instance. Note that this method calls builders which were attached to the
-    # class with Cell::Base.build - this might lead to a different cell being returned.
-    def create_cell_for(controller, name, *args)
-      class_from_cell_name(name).build_for(controller, *args)
-    end
-
-    def build_for(controller, *args)
-      build_class_for(controller, *args).
-      new(controller)
-    end
-
-    # Adds a builder to the cell class. Builders are used in #render_cell to find out the concrete
-    # class for rendering. This is helpful if you frequently want to render subclasses according
-    # to different circumstances (e.g. login situations) and you don't want to place these deciders in
-    # your view code.
-    #
-    # Passes the opts hash from #render_cell into the block. The block is executed in controller context. 
-    # Multiple build blocks are ORed, if no builder matches the building cell is used.
-    #
-    # Example:
-    #
-    # Consider two different user box cells in your app.
-    #
-    #   class AuthorizedUserBox < UserInfoBox
-    #   end
-    #
-    #   class AdminUserBox < UserInfoBox
-    #   end
-    #
-    # Now you don't want to have deciders all over your views - use a declarative builder.
-    #
-    #   UserInfoBox.build do |opts|
-    #     AuthorizedUserBox if user_signed_in?
-    #     AdminUserBox if admin_signed_in?
-    #   end
-    #
-    # In your view #render_cell will instantiate the right cell for you now.
-    def build(&block)
-      builders << block
-    end
-
-    # The cell class constant for +cell_name+.
-    def class_from_cell_name(cell_name)
-      "#{cell_name}_cell".classify.constantize
-    end
-
-  protected
-    def build_class_for(controller, *args)
-      builders.each do |blk|
-        klass = controller.instance_exec(*args, &blk) and return klass
-      end
-      self
-    end
-
-    def builders
-      @builders ||= []
-    end
   end
 end

lib/cell/base.rb

@@ -1,9 +1,11 @@
 require 'abstract_controller'
 require 'cell'
+require 'cell/builder'
 
 module Cell
   class Base < AbstractController::Base
     include Cell
+    extend Builder
     include AbstractController
     include Rendering, Layouts, Helpers, Callbacks, Translation, Logger
 

lib/cell/builder.rb

@@ -0,0 +1,65 @@
+module Cell
+  module Builder
+    # Creates a cell instance. Note that this method calls builders which were attached to the
+    # class with Cell::Base.build - this might lead to a different cell being returned.
+    def create_cell_for(controller, name, *args)
+      class_from_cell_name(name).build_for(controller, *args)
+    end
+
+    def build_for(controller, *args)
+      build_class_for(controller, *args).
+      new(controller)
+    end
+
+    # Adds a builder to the cell class. Builders are used in #render_cell to find out the concrete
+    # class for rendering. This is helpful if you frequently want to render subclasses according
+    # to different circumstances (e.g. login situations) and you don't want to place these deciders in
+    # your view code.
+    #
+    # Passes the opts hash from #render_cell into the block. The block is executed in controller context. 
+    # Multiple build blocks are ORed, if no builder matches the building cell is used.
+    #
+    # Example:
+    #
+    # Consider two different user box cells in your app.
+    #
+    #   class AuthorizedUserBox < UserInfoBox
+    #   end
+    #
+    #   class AdminUserBox < UserInfoBox
+    #   end
+    #
+    # Now you don't want to have deciders all over your views - use a declarative builder.
+    #
+    #   UserInfoBox.build do |opts|
+    #     AuthorizedUserBox if user_signed_in?
+    #     AdminUserBox if admin_signed_in?
+    #   end
+    #
+    # In your view #render_cell will instantiate the right cell for you now.
+    def build(&block)
+      builders << block
+    end
+
+    # The cell class constant for +cell_name+.
+    def class_from_cell_name(cell_name)
+      "#{cell_name}_cell".classify.constantize
+    end
+
+  protected
+    def build_class_for(controller, *args)
+      builders.each do |blk|
+        klass = run_builder_block(blk, controller, *args) and return klass
+      end
+      self
+    end
+
+    def run_builder_block(blk, controller, *args)
+      controller.instance_exec(*args, &blk)
+    end
+
+    def builders
+      @builders ||= []
+    end
+  end
+end