[Haml] [HTML] Work even if Hpricot is loaded first.

Closes gh-324
Closes gh-322

doc-src/HAML_CHANGELOG.md

@@ -3,6 +3,10 @@
 * Table of contents
 {:toc}
 
+## 3.0.25 (Unreleased)
+
+* HTML-to-Haml conversion now works within Ruby even if Hpricot is loaded before `haml/html`.
+
 ## 3.0.24
 
 [Tagged on GitHub](http://github.com/nex3/haml/commit/3.0.24).

lib/haml/html.rb

@@ -3,82 +3,91 @@ require File.dirname(__FILE__) + '/../haml'
 require 'haml/engine'
 require 'rubygems'
 require 'cgi'
+require 'hpricot'
 
 module Haml
   class HTML
     # A module containing utility methods that every Hpricot node
     # should have.
     module Node
-      # Whether this node has already been converted to Haml.
-      # Only used for text nodes and elements.
-      #
-      # @return [Boolean]
-      attr_accessor :converted_to_haml
+      # We have to do everything in `#included`
+      # rather than including the methods in the module itself
+      # because if we do that, they don't propagate to the already-defined subclasses
+      # of the modules including this.
+      def self.included(base)
+        base.class_eval do
+          # Whether this node has already been converted to Haml.
+          # Only used for text nodes and elements.
+          #
+          # @return [Boolean]
+          attr_accessor :converted_to_haml
 
-      # Returns the Haml representation of the given node.
-      #
-      # @param tabs [Fixnum] The indentation level of the resulting Haml.
-      # @option options (see Haml::HTML#initialize)
-      def to_haml(tabs, options)
-        return "" if converted_to_haml || to_s.strip.empty?
-        text = uninterp(self.to_s)
-        node = next_node
-        while node.is_a?(::Hpricot::Elem) && node.name == "haml:loud"
-          node.converted_to_haml = true
-          text << '#{' <<
-            CGI.unescapeHTML(node.inner_text).gsub(/\n\s*/, ' ').strip << '}'
+          # Returns the Haml representation of the given node.
+          #
+          # @param tabs [Fixnum] The indentation level of the resulting Haml.
+          # @option options (see Haml::HTML#initialize)
+          def to_haml(tabs, options)
+            return "" if converted_to_haml || to_s.strip.empty?
+            text = uninterp(self.to_s)
+            node = next_node
+            while node.is_a?(::Hpricot::Elem) && node.name == "haml:loud"
+              node.converted_to_haml = true
+              text << '#{' <<
+                CGI.unescapeHTML(node.inner_text).gsub(/\n\s*/, ' ').strip << '}'
 
-          if node.next_node.is_a?(::Hpricot::Text)
-            node = node.next_node
-            text << uninterp(node.to_s)
-            node.converted_to_haml = true
+              if node.next_node.is_a?(::Hpricot::Text)
+                node = node.next_node
+                text << uninterp(node.to_s)
+                node.converted_to_haml = true
+              end
+
+              node = node.next_node
+            end
+            return parse_text_with_interpolation(text, tabs)
           end
 
-          node = node.next_node
-        end
-        return parse_text_with_interpolation(text, tabs)
-      end
+          private
 
-      private
+          def erb_to_interpolation(text, options)
+            return text unless options[:erb]
+            text = CGI.escapeHTML(uninterp(text))
+            %w[<haml:loud> </haml:loud>].each {|str| text.gsub!(CGI.escapeHTML(str), str)}
+            ::Hpricot::XML(text).children.inject("") do |str, elem|
+              if elem.is_a?(::Hpricot::Text)
+                str + CGI.unescapeHTML(elem.to_s)
+              else # <haml:loud> element
+                str + '#{' + CGI.unescapeHTML(elem.innerText.strip) + '}'
+              end
+            end
+          end
 
-      def erb_to_interpolation(text, options)
-        return text unless options[:erb]
-        text = CGI.escapeHTML(uninterp(text))
-        %w[<haml:loud> </haml:loud>].each {|str| text.gsub!(CGI.escapeHTML(str), str)}
-        ::Hpricot::XML(text).children.inject("") do |str, elem|
-          if elem.is_a?(::Hpricot::Text)
-            str + CGI.unescapeHTML(elem.to_s)
-          else # <haml:loud> element
-            str + '#{' + CGI.unescapeHTML(elem.innerText.strip) + '}'
+          def tabulate(tabs)
+            '  ' * tabs
+          end
+
+          def uninterp(text)
+            text.gsub('#{', '\#{') #'
+          end
+
+          def attr_hash
+            attributes.to_hash
+          end
+
+          def parse_text(text, tabs)
+            parse_text_with_interpolation(uninterp(text), tabs)
+          end
+
+          def parse_text_with_interpolation(text, tabs)
+            text.strip!
+            return "" if text.empty?
+
+            text.split("\n").map do |line|
+              line.strip!
+              "#{tabulate(tabs)}#{'\\' if Haml::Engine::SPECIAL_CHARACTERS.include?(line[0])}#{line}\n"
+            end.join
           end
         end
       end
-
-      def tabulate(tabs)
-        '  ' * tabs
-      end
-
-      def uninterp(text)
-        text.gsub('#{', '\#{') #'
-      end
-
-      def attr_hash
-        attributes.to_hash
-      end
-
-      def parse_text(text, tabs)
-        parse_text_with_interpolation(uninterp(text), tabs)
-      end
-
-      def parse_text_with_interpolation(text, tabs)
-        text.strip!
-        return "" if text.empty?
-
-        text.split("\n").map do |line|
-          line.strip!
-          "#{tabulate(tabs)}#{'\\' if Haml::Engine::SPECIAL_CHARACTERS.include?(line[0])}#{line}\n"
-        end.join
-      end
     end
   end
 end
@@ -98,8 +107,6 @@ module Hpricot
   end
 end
 
-require 'hpricot'
-
 # @private
 HAML_TAGS = %w[haml:block haml:loud haml:silent]