Refactor to create tags with a parse class method instead of new.

By moving parse out of the initializer, we can call super at the start of
the initializers for subclasses, and avoid the nasty allocate hack.

History.md

@@ -3,6 +3,7 @@
 ## 3.0.0 / not yet released / branch "master"
 
 * ...
+* Tag#parse is called after initialize, which now takes options instead of tokens as the 3rd argument. See #321 [Dylan Thacker-Smith, dylanahsmith]
 * Raise `Liquid::ArgumentError` instead of `::ArgumentError` when filter has wrong number of arguments #309 [Bogdan Gusiev, bogdan]
 * Add a to_s default for liquid drops, see #306 [Adam Doeler, releod]
 * Add strip, lstrip, and rstrip to standard filters [Florian Weingarten, fw42]

lib/liquid/block.rb

@@ -31,7 +31,7 @@ module Liquid
 
             # fetch the tag from registered blocks
             if tag = Template.tags[$1]
-              new_tag = tag.new_with_options($1, $2, tokens, @options || {})
+              new_tag = tag.parse($1, $2, tokens, @options)
               @blank &&= new_tag.blank?
               @nodelist << new_tag
               @children << new_tag

lib/liquid/document.rb

@@ -1,9 +1,8 @@
 module Liquid
   class Document < Block
-    # we don't need markup to open this block
+    def self.parse(tokens, options={})
-    def initialize(tokens, options = {})
+      # we don't need markup to open this block
-      @options = options
+      super(nil, nil, tokens, options)
-      parse(tokens)
     end
 
     # There isn't a real delimiter

lib/liquid/tag.rb

@@ -3,20 +3,20 @@ module Liquid
     attr_accessor :options
     attr_reader :nodelist, :warnings
 
-    def self.new_with_options(tag_name, markup, tokens, options)
+    class << self
-      # Forgive me Matz for I have sinned. I know this code is weird
+      def parse(tag_name, markup, tokens, options)
-      # but it was necessary to maintain API compatibility.
+        tag = new(tag_name, markup, options)
-      new_tag = self.allocate
+        tag.parse(tokens)
-      new_tag.options = options
+        tag
-      new_tag.send(:initialize, tag_name, markup, tokens)
+      end
-      new_tag
+
+      private :new
     end
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
       @tag_name   = tag_name
       @markup     = markup
-      @options    ||= {} # needs || because might be set before initialize
+      @options    = options
-      parse(tokens)
     end
 
     def parse(tokens)

lib/liquid/tags/assign.rb

@@ -11,15 +11,14 @@ module Liquid
   class Assign < Tag
     Syntax = /(#{VariableSignature}+)\s*=\s*(.*)\s*/o
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       if markup =~ Syntax
         @to = $1
         @from = Variable.new($2)
       else
         raise SyntaxError.new options[:locale].t("errors.syntax.assign")
       end
-
-      super
     end
 
     def render(context)

lib/liquid/tags/capture.rb

@@ -14,14 +14,13 @@ module Liquid
   class Capture < Block
     Syntax = /(\w+)/
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       if markup =~ Syntax
         @to = $1
       else
         raise SyntaxError.new(options[:locale].t("errors.syntax.capture"))
       end
-
-      super
     end
 
     def render(context)

lib/liquid/tags/case.rb

@@ -3,7 +3,8 @@ module Liquid
     Syntax     = /(#{QuotedFragment})/o
     WhenSyntax = /(#{QuotedFragment})(?:(?:\s+or\s+|\s*\,\s*)(#{QuotedFragment}.*))?/o
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       @blocks = []
 
       if markup =~ Syntax
@@ -11,8 +12,6 @@ module Liquid
       else
         raise SyntaxError.new(options[:locale].t("errors.syntax.case"))
       end
-
-      super
     end
 
     def nodelist

lib/liquid/tags/cycle.rb

@@ -15,7 +15,8 @@ module Liquid
     SimpleSyntax = /\A#{QuotedFragment}+/o
     NamedSyntax  = /\A(#{QuotedFragment})\s*\:\s*(.*)/o
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       case markup
       when NamedSyntax
         @variables = variables_from_string($2)
@@ -26,7 +27,6 @@ module Liquid
       else
         raise SyntaxError.new(options[:locale].t("errors.syntax.cycle"))
       end
-      super
     end
 
     def render(context)

lib/liquid/tags/decrement.rb

@@ -19,10 +19,9 @@ module Liquid
   #    Hello: -3
   #
   class Decrement < Tag
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
-      @variable = markup.strip
-
       super
+      @variable = markup.strip
     end
 
     def render(context)

lib/liquid/tags/for.rb

@@ -46,10 +46,10 @@ module Liquid
   class For < Block
     Syntax = /\A(#{VariableSegment}+)\s+in\s+(#{QuotedFragment}+)\s*(reversed)?/o
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       parse_with_selected_parser(markup)
       @nodelist = @for_block = []
-      super
     end
 
     def nodelist

lib/liquid/tags/if.rb

@@ -14,10 +14,10 @@ module Liquid
     ExpressionsAndOperators = /(?:\b(?:\s?and\s?|\s?or\s?)\b|(?:\s*(?!\b(?:\s?and\s?|\s?or\s?)\b)(?:#{QuotedFragment}|\S+)\s*)+)/o
     BOOLEAN_OPERATORS = %w(and or)
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       @blocks = []
       push_block('if', markup)
-      super
     end
 
     def nodelist

lib/liquid/tags/include.rb

@@ -17,7 +17,9 @@ module Liquid
   class Include < Tag
     Syntax = /(#{QuotedFragment}+)(\s+(?:with|for)\s+(#{QuotedFragment}+))?/o
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
+
       if markup =~ Syntax
 
         @template_name = $1
@@ -31,8 +33,6 @@ module Liquid
       else
         raise SyntaxError.new(options[:locale].t("errors.syntax.include"))
       end
-
-      super
     end
 
     def parse(tokens)

lib/liquid/tags/increment.rb

@@ -15,9 +15,9 @@ module Liquid
   #    Hello: 2
   #
   class Increment < Tag
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
-      @variable = markup.strip
       super
+      @variable = markup.strip
     end
 
     def render(context)

lib/liquid/tags/table_row.rb

@@ -2,7 +2,8 @@ module Liquid
   class TableRow < Block
     Syntax = /(\w+)\s+in\s+(#{QuotedFragment}+)/o
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       if markup =~ Syntax
         @variable_name = $1
         @collection_name = $2
@@ -13,8 +14,6 @@ module Liquid
       else
         raise SyntaxError.new(options[:locale].t("errors.syntax.table_row"))
       end
-
-      super
     end
 
     def render(context)

lib/liquid/template.rb

@@ -72,7 +72,7 @@ module Liquid
     # Parse source code.
     # Returns self for easy chaining
     def parse(source, options = {})
-      @root = Document.new(tokenize(source), DEFAULT_OPTIONS.merge(options))
+      @root = Document.parse(tokenize(source), DEFAULT_OPTIONS.merge(options))
       @warnings = nil
       self
     end

performance/shopify/comment_form.rb

@@ -1,15 +1,15 @@
 class CommentForm < Liquid::Block
   Syntax = /(#{Liquid::VariableSignature}+)/
 
-  def initialize(tag_name, markup, tokens)
+  def initialize(tag_name, markup, options)
+    super
+
     if markup =~ Syntax
       @variable_name = $1
       @attributes = {}
     else
       raise SyntaxError.new("Syntax Error in 'comment_form' - Valid syntax: comment_form [article]")
     end
-
-    super
   end
 
   def render(context)

performance/shopify/paginate.rb

@@ -1,7 +1,9 @@
 class Paginate < Liquid::Block
   Syntax     = /(#{Liquid::QuotedFragment})\s*(by\s*(\d+))?/
 
-  def initialize(tag_name, markup, tokens)
+  def initialize(tag_name, markup, options)
+    super
+
     @nodelist = []
 
     if markup =~ Syntax
@@ -19,8 +21,6 @@ class Paginate < Liquid::Block
     else
       raise SyntaxError.new("Syntax Error in tag 'paginate' - Valid syntax: paginate [collection] by number")
     end
-
-    super
   end
 
   def render(context)

test/liquid/tags/standard_tag_test.rb

@@ -4,7 +4,7 @@ class StandardTagTest < Test::Unit::TestCase
   include Liquid
 
   def test_tag
-    tag = Tag.new('tag', [], [])
+    tag = Tag.parse('tag', [], [], {})
     assert_equal 'liquid::tag', tag.name
     assert_equal '', tag.render(Context.new)
   end