pipeline.rb in html-pipeline-2.7.1

- old
+ new

@@ -42,9 +42,15 @@
     autoload :TextileFilter,         'html/pipeline/textile_filter'
     autoload :TableOfContentsFilter, 'html/pipeline/toc_filter'
     autoload :TextFilter,            'html/pipeline/text_filter'
 
     class MissingDependencyError < LoadError; end
+    def self.require_dependency(name, requirer)
+      require name
+    rescue LoadError => e
+      raise MissingDependencyError,
+        "Missing dependency '#{name}' for #{requirer}. See README.md for details.\n#{e.class.name}: #{e}"
+    end
 
     # Our DOM implementation.
     DocumentFragment = Nokogiri::HTML::DocumentFragment
 
     # Parse a String into a DocumentFragment object. When a DocumentFragment is