Parse expressions in Liquid::Variable#parse.

lib/liquid/variable.rb

@@ -35,15 +35,16 @@ module Liquid
 
     def lax_parse(markup)
       @filters = []
-      if markup =~ /\s*(#{QuotedFragment})(.*)/om
-        @name = Regexp.last_match(1)
-        if Regexp.last_match(2) =~ /#{FilterSeparator}\s*(.*)/om
-          filters = Regexp.last_match(1).scan(FilterParser)
+      if markup =~ /(#{QuotedFragment})(.*)/om
+        name_markup, filter_markup = $1, $2
+        @name = Expression.parse(name_markup)
+        if filter_markup =~ /#{FilterSeparator}\s*(.*)/om
+          filters = $1.scan(FilterParser)
           filters.each do |f|
             if f =~ /\w+/
               filtername = Regexp.last_match(0)
               filterargs = f.scan(/(?:#{FilterArgumentSeparator}|#{ArgumentSeparator})\s*((?:\w+\s*\:\s*)?#{QuotedFragment})/o).flatten
-              @filters << [filtername, filterargs]
+              @filters << parse_filter_expressions(filtername, filterargs)
             end
           end
         end
@@ -53,7 +54,7 @@ module Liquid
     def strict_parse(markup)
       # Very simple valid cases
       if markup =~ EasyParse
-        @name = $1
+        @name = Expression.parse($1)
         @filters = []
         return
       end
@@ -61,11 +62,11 @@ module Liquid
       @filters = []
       p = Parser.new(markup)
       # Could be just filters with no input
-      @name = p.look(:pipe) ? ''.freeze : p.expression
+      @name = p.look(:pipe) ? nil : Expression.parse(p.expression)
       while p.consume?(:pipe)
         filtername = p.consume(:id)
         filterargs = p.consume?(:colon) ? parse_filterargs(p) : []
-        @filters << [filtername, filterargs]
+        @filters << parse_filter_expressions(filtername, filterargs)
       end
       p.consume(:end_of_string)
     end
@@ -81,28 +82,52 @@ module Liquid
     end
 
     def render(context)
-      return ''.freeze if @name.nil?
-      @filters.inject(context[@name]) do |output, filter|
-        filterargs = []
-        keyword_args = {}
-        filter[1].to_a.each do |a|
-          if matches = a.match(/\A#{TagAttributes}\z/o)
-            keyword_args[matches[1]] = context[matches[2]]
-          else
-            filterargs << context[a]
-          end
+      return ''.freeze unless @name
+      @filters.inject(context.evaluate(@name)) do |output, (filter_name, filter_args, filter_kwargs)|
+        filter_args = evaluate_filter_expressions(context, filter_args, filter_kwargs)
+        output = context.invoke(filter_name, output, *filter_args)
+      end.tap{ |obj| taint_check(obj) }
+    end
+
+    private
+
+    def parse_filter_expressions(filter_name, unparsed_args)
+      filter_args = []
+      keyword_args = {}
+      unparsed_args.each do |a|
+        if matches = a.match(/\A#{TagAttributes}\z/o)
+          keyword_args[matches[1]] = Expression.parse(matches[2])
+        else
+          filter_args << Expression.parse(a)
         end
-        filterargs << keyword_args unless keyword_args.empty?
-        output = context.invoke(filter[0], output, *filterargs)
-      end.tap do |obj|
-        if obj.tainted?
-          case Template.taint_mode
-          when :warn
-            @warnings ||= []
-            @warnings << "variable '#{@name}' is tainted and was not escaped"
-          when :error
-            raise TaintedError, "Error - variable '#{@name}' is tainted and was not escaped"
-          end
+      end
+      result = [filter_name, filter_args]
+      result << keyword_args unless keyword_args.empty?
+      result
+    end
+
+    def evaluate_filter_expressions(context, filter_args, filter_kwargs)
+      parsed_args = filter_args.map{ |expr| context.evaluate(expr) }
+      if filter_kwargs
+        parsed_kwargs = {}
+        filter_kwargs.each do |key, expr|
+          parsed_kwargs[key] = context.evaluate(expr)
+        end
+        parsed_args << parsed_kwargs
+      end
+      parsed_args
+    end
+
+    def taint_check(obj)
+      if obj.tainted?
+        @markup =~ QuotedFragment
+        name = Regexp.last_match(0)
+        case Template.taint_mode
+        when :warn
+          @warnings ||= []
+          @warnings << "variable '#{name}' is tainted and was not escaped"
+        when :error
+          raise TaintedError, "Error - variable '#{name}' is tainted and was not escaped"
         end
       end
     end