if blocks work with filtered variables

lib/liquid.rb

@@ -22,7 +22,7 @@
 $LOAD_PATH.unshift(File.dirname(__FILE__))
 
 module Liquid
-  FilterSperator              = /\|/
+  FilterSeparator              = /\|/
   ArgumentSeparator           = ','
   FilterArgumentSeparator     = ':'
   VariableAttributeSeparator  = '.'
@@ -33,7 +33,12 @@ module Liquid
   VariableStart               = /\{\{/
   VariableEnd                 = /\}\}/
   VariableIncompleteEnd       = /\}\}?/
-  QuotedFragment              = /"[^"]+"|'[^']+'|[^\s,|]+/
+  QuotedFragment              = /"[^"]+"|'[^']+'|[^\s,\|]+/
+  StrictQuotedFragment        = /"[^"]+"|'[^']+'|[^\s,\|,\:,\,]+/
+  FirstFilterArgument         = /#{FilterArgumentSeparator}(?:#{StrictQuotedFragment})/
+  OtherFilterArgument         = /#{ArgumentSeparator}(?:#{StrictQuotedFragment})/
+  SpacelessFilter             = /#{FilterSeparator}(?:#{StrictQuotedFragment})(?:#{FirstFilterArgument}(?:#{OtherFilterArgument})*)?/
+  Expression                  = /(?:#{QuotedFragment}(?:#{SpacelessFilter})*)/
   TagAttributes               = /(\w+)\s*\:\s*(#{QuotedFragment})/
   TemplateParser              = /(#{TagStart}.*?#{TagEnd}|#{VariableStart}.*?#{VariableIncompleteEnd})/
   VariableParser              = /\[[^\]]+\]|#{VariableSegment}+/

lib/liquid/context.rb

@@ -133,6 +133,9 @@ module Liquid
         :blank?
       when 'empty'
         :empty?
+      # filtered variables
+      when SpacelessFilter
+        filtered_variable(key)
       # Single quoted strings
       when /^'(.*)'$/
         $1.to_s
@@ -221,5 +224,9 @@ module Liquid
 
       object
     end
+    
+    def filtered_variable(markup)
+      Variable.new(markup).render(self)
+    end
   end
 end

lib/liquid/tags/if.rb

@@ -13,7 +13,7 @@ module Liquid
   #
   class If < Block
     SyntaxHelp = "Syntax Error in tag 'if' - Valid syntax: if [expression]"
-    Syntax = /(#{QuotedFragment})\s*([=!<>a-z_]+)?\s*(#{QuotedFragment})?/
+    Syntax = /(#{Expression})\s*([=!<>a-z_]+)?\s*(#{Expression})?/
     
     def initialize(tag_name, markup, tokens)    
     

lib/liquid/variable.rb

@@ -19,8 +19,8 @@ module Liquid
       @filters = []
       if match = markup.match(/\s*(#{QuotedFragment})/)
         @name = match[1]
-        if markup.match(/#{FilterSperator}\s*(.*)/)
-          filters = Regexp.last_match(1).split(/#{FilterSperator}/)
+        if markup.match(/#{FilterSeparator}\s*(.*)/)
+          filters = Regexp.last_match(1).split(/#{FilterSeparator}/)
         
           filters.each do |f|    
             if matches = f.match(/\s*(\w+)/)

test/if_else_test.rb

@@ -112,6 +112,13 @@ class IfElseTest < Test::Unit::TestCase
     assert_template_result('elsif','{% if false %}if{% elsif true %}elsif{% endif %}')    
   end
   
+  def test_with_filtered_expressions
+    assert_template_result('yes','{% if "BLAH"|downcase == "blah" %}yes{% endif %}')
+    assert_template_result('yes','{% if "FOO BAR"|truncatewords:1,"--" == "FOO--" %}yes{% endif %}')
+    assert_template_result('yes','{% if "FOO BAR"|truncatewords:1,"--"|downcase == "foo--" %}yes{% endif %}')
+    assert_template_result('yes','{% if "foo--" == "FOO BAR"|truncatewords:1,"--"|downcase %}yes{% endif %}')
+  end
+  
   def test_syntax_error_no_variable
     assert_raise(SyntaxError){ assert_template_result('', '{% if jerry == 1 %}')}
   end