Highlight helper highlights one or many terms in a single pass.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6493 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Highlight helper highlights one or many terms in a single pass.  [Jeremy Kemper]
+
 * Dropped the use of ; as a separator of non-crud actions on resources and went back to the vanilla slash. It was a neat idea, but lots of the non-crud actions turned out not to be RPC (as the ; was primarily intended to discourage), but legitimate sub-resources, like /parties/recent, which didn't deserve the uglification of /parties;recent. Further more, the semicolon caused issues with caching and HTTP authentication in Safari. Just Not Worth It [DHH]
 
 * Added that FormTagHelper#submit_tag will return to its original state if the submit fails and you're using :disable_with [DHH]

actionpack/lib/action_view/helpers/text_helper.rb

@@ -38,15 +38,22 @@ module ActionView
         (text.chars.length > length ? text.chars[0...l] + truncate_string : text).to_s
       end
 
-      # Highlights +phrase+ everywhere it is found in +text+ by inserting it into
+      # Highlights one or more +phrases+ everywhere in +text+ by inserting it into
       # a +highlighter+ string. The highlighter can be specialized by passing +highlighter+ 
       # as a single-quoted string with \1 where the phrase is to be inserted.
       #
       #   highlight('You searched for: rails', 'rails')  
-      #    => You searched for: <strong class="highlight">rails</strong>
-      def highlight(text, phrase, highlighter = '<strong class="highlight">\1</strong>')
-        if phrase.blank? then return text end
-        text.gsub(/(#{Regexp.escape(phrase)})/i, highlighter) unless text.nil?
+      #   # => You searched for: <strong class="highlight">rails</strong>
+      #
+      #   highlight('You searched for: rails', ['for', 'rails'], '<em>\1</em>')  
+      #   # => You searched <em>for</em>: <em>rails</em>
+      def highlight(text, phrases, highlighter = '<strong class="highlight">\1</strong>')
+        if text.blank? || phrases.blank?
+          text
+        else
+          match = Array(phrases).map { |p| Regexp.escape(p) }.join('|')
+          text.gsub(/(#{match})/i, highlighter)
+        end
       end
 
       # Extracts an excerpt from +text+ that matches the first instance of +phrase+. 

actionpack/test/template/text_helper_test.rb

@@ -65,6 +65,8 @@ class TextHelperTest < Test::Unit::TestCase
       "This text is not changed because we supplied an empty phrase",
       highlight("This text is not changed because we supplied an empty phrase", nil)
     )
+
+    assert_equal '   ', highlight('   ', 'blank text is returned verbatim')
   end
 
   def test_highlighter_with_regexp
@@ -84,6 +86,10 @@ class TextHelperTest < Test::Unit::TestCase
     )
   end
 
+  def test_highlighting_multiple_phrases_in_one_pass
+    assert_equal %(<em>wow</em> <em>em</em>), highlight('wow em', %w(wow em), '<em>\1</em>')
+  end
+
   def test_excerpt
     assert_equal("...is a beautiful morni...", excerpt("This is a beautiful morning", "beautiful", 5))
     assert_equal("This is a...", excerpt("This is a beautiful morning", "this", 5))