Added the list_for helper (as demoed at RailsConf)

git-svn-id: svn://hamptoncatlin.com/haml/trunk@44 7063305b-7217-0410-af8c-cdc13e5119b9

lib/haml/helpers.rb

@@ -1,5 +1,7 @@
 module Haml
   module Helpers
+    # Flatten will take any string, find all the endlines (via \n)
+    # and convert them to html entities for endlines.
     def flatten(input)
       input.gsub(/\n/, '
').gsub(/\r/, '')
     end
@@ -18,5 +20,24 @@ module Haml
     def count_soft_tabs(line)
       line.index(/[^ ]/) ? [line.index(/[^ ]/)/2, line.strip] : []
     end
+
+    # List_for is a really nifty little helper that helps
+    # cleanup your code. Basically, give it an array of
+    # objects, and then pass in a block that tells how
+    # what to put out, and you will get each block item
+    # in rows of <li> tags.
+    #
+    # For instance:
+    #   list_of([['hello'], ['yall']]) { |i| i[0] }
+    # or
+    #   list_of(['hello', 'yall'])
+    #
+    # Produces:
+    #   <li>hello</li>
+    #   <li>yall</li>
+    #
+    def list_of(array)
+      (array.collect { |i| "<li>#{yield(i)}</li>" }).join("\n")
+    end
   end
 end

test/helper_test.rb

@@ -5,6 +5,7 @@ $:.unshift File.join(File.dirname(__FILE__), "..", "lib")
 
 require 'rubygems'
 require 'action_view'
+require 'active_support'
 
 class HamlTest < Test::Unit::TestCase
   include Haml::Helpers
@@ -28,4 +29,9 @@ class HamlTest < Test::Unit::TestCase
     assert_equal("  ", tabs(1))
     assert_equal("          ", tabs(5))
   end
+
+  def test_list_of
+    assert_equal("<li>1</li>\n<li>2</li>", (list_of([1, 2]) { |i| i.to_s}))
+    assert_equal("<li>1</li>", (list_of([[1]]) { |i| i.first}))
+  end
 end