add the Publisher class to handle publishing logic

lib/jekyll.rb

@@ -50,6 +50,7 @@ require 'jekyll/related_posts'
 require 'jekyll/cleaner'
 require 'jekyll/entry_filter'
 require 'jekyll/layout_reader'
+require 'jekyll/publisher'
 
 # extensions
 require 'jekyll/plugin'

lib/jekyll/publisher.rb

@@ -0,0 +1,21 @@
+module Jekyll
+  class Publisher
+    def initialize(site)
+      @site = site
+    end
+
+    def publish?(thing)
+      can_be_published?(thing) && !hidden_in_the_future?(thing)
+    end
+
+    private
+
+    def can_be_published?(thing)
+      thing.data.fetch('published', true) || @site.unpublished
+    end
+
+    def hidden_in_the_future?(thing)
+      thing.is_a?(Post) && !@site.future && thing.date > @site.time
+    end
+  end
+end