Fully move section data retrieval logic into section

Author: Envek

lib/tram/page.rb

@@ -16,7 +16,7 @@ def section(name, options = {})
       raise "Section #{n} already exists" if @__sections.key?(n)
 
       section = Section.new(n, options)
-      define_section_method(n, options[:value]) if options[:value]
+      define_section_method(n, section) if options[:value]
       @__sections[n] = section
     end
 
@@ -27,8 +27,8 @@ def url_helper(name)
 
     private
 
-    def define_section_method(n, value)
-      define_method(n) { instance_exec(&value) }
+    def define_section_method(n, section)
+      define_method(n) { section.value(self) }
     end
 
     def inherited(subclass)

lib/tram/page/section.rb

@@ -4,6 +4,7 @@ class Tram::Page::Section
   extend Dry::Initializer
 
   param  :name
+  option :value,  optional: true, as: :getter
   option :if,     optional: true, as: :positive
   option :unless, optional: true, as: :negative
 
@@ -12,12 +13,12 @@ def call(page)
     show?(page) ? { name => value(page) } : {}
   end
 
-  private
-
   def value(page)
-    page.public_send(name)
+    getter ? page.instance_exec(&getter) : page.public_send(name)
   end
 
+  private
+
   def show?(page)
     condition  = true
     condition &= page.send(positive)  if positive