Do not include empty blocks, this way, we avoid empty sidebars if not needed.

src/kernel/content/cms_block.e

@@ -23,7 +23,12 @@ feature -- Access
 	html_options: detachable CMS_HTML_OPTIONS
 			-- Optional addition html options.
 
-feature -- status report
+feature -- Status report
+
+	is_empty: BOOLEAN
+			-- Is current block empty?
+		deferred
+		end
 
 	is_enabled: BOOLEAN
 			-- Is current block enabled?
@@ -93,4 +98,7 @@ feature -- Status report
 			end
 		end
 
+note
+	copyright: "2011-2015, Jocelyn Fiat, Javier Velilla, Eiffel Software and others"
+	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
 end

src/kernel/content/cms_block_region.e

@@ -21,11 +21,10 @@ feature {NONE} -- Initialization
 feature -- Access
 
 	name: READABLE_STRING_8
-		-- Block region name.
+			-- Block region name.
 
 	blocks: ARRAYED_LIST [CMS_BLOCK]
-		-- List of blocks.
+			-- List of blocks.
-
 
 feature -- Element change
 
@@ -35,8 +34,15 @@ feature -- Element change
 			blocks.force (b)
 		end
 
-;note
+	remove (b: CMS_BLOCK)
-	copyright: "2011-2014, Jocelyn Fiat, Eiffel Software and others"
+		require
+			has_block_b: blocks.has (b)
+		do
+			blocks.prune_all (b)
+		end
+
+note
+	copyright: "2011-2015, Jocelyn Fiat, Javier Velilla, Eiffel Software and others"
 	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
 	source: "[
 			Eiffel Software

src/kernel/content/cms_content_block.e

@@ -49,6 +49,12 @@ feature -- Access
 
 feature -- Status report
 
+	is_empty: BOOLEAN
+			-- Is current block empty?
+		do
+			Result := is_raw and content.is_empty
+		end
+
 	is_raw: BOOLEAN assign set_is_raw
 			-- Is raw?
 			-- If True, do not get wrapped it with block specific div	
@@ -87,7 +93,7 @@ feature -- Conversion
 			end
 		end
 note
-	copyright: "2011-2014, Jocelyn Fiat, Eiffel Software and others"
+	copyright: "2011-2015, Jocelyn Fiat, Javier Velilla, Eiffel Software and others"
 	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
 	source: "[
 			Eiffel Software

src/kernel/content/cms_menu_block.e

@@ -31,6 +31,12 @@ feature -- Access
 
 feature -- Status report
 
+	is_empty: BOOLEAN
+			-- Is current block empty?
+		do
+			Result := menu.is_empty
+		end
+
 	is_horizontal: BOOLEAN assign set_is_horizontal
 		-- Is horizontal layout for the menu?
 
@@ -72,4 +78,7 @@ feature -- Conversion
 			Result := a_theme.menu_html (menu, is_horizontal, html_options)
 		end
 
+note
+	copyright: "2011-2015, Jocelyn Fiat, Javier Velilla, Eiffel Software and others"
+	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
 end

src/kernel/content/cms_smarty_template_block.e

@@ -69,6 +69,9 @@ feature -- Access
 
 feature -- Status report
 
+	is_empty: BOOLEAN = False
+			-- Is current block empty?
+
 	is_raw: BOOLEAN
 			-- Is raw?
 			-- If True, do not get wrapped it with block specific div	
@@ -192,4 +195,7 @@ feature -- Debug
 			end
 			Result.append ("%N}")
 		end
+note
+	copyright: "2011-2015, Jocelyn Fiat, Javier Velilla, Eiffel Software and others"
+	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
 end

src/service/response/cms_response.e

@@ -738,7 +738,9 @@ feature -- Generation
 	prepare (page: CMS_HTML_PAGE)
 		local
 			lnk: CMS_LINK
+			l_region: CMS_BLOCK_REGION
 			l_menu_list_prepared: ARRAYED_LIST [CMS_LINK_COMPOSITE]
+			l_empty_blocks: detachable ARRAYED_LIST [CMS_BLOCK]
 		do
 				-- Menu
 			create {CMS_LOCAL_LINK} lnk.make ("Home", "")
@@ -756,14 +758,29 @@ feature -- Generation
 			across
 				regions as reg_ic
 			loop
+				l_region := reg_ic.item
 				across
-					reg_ic.item.blocks as ic
+					l_region.blocks as ic
 				loop
 					if attached {CMS_MENU_BLOCK} ic.item as l_menu_block then
 						l_menu_list_prepared.force (l_menu_block.menu)
 						prepare_links (l_menu_block.menu)
+						if l_menu_block.menu.is_empty then
+							if l_empty_blocks = Void then
+								create l_empty_blocks.make (1)
+							end
+							l_empty_blocks.force (l_menu_block)
+						end
 					end
 				end
+				if l_empty_blocks /= Void then
+					across
+						l_empty_blocks as ic
+					loop
+						l_region.remove (ic.item)
+					end
+					l_empty_blocks := Void
+				end
 			end
 
 				-- Prepare menu not in a block.