Context

- Check arity of proc before calling, to prevent error when using ruby 1.9.1+

Code beautifer
  - context.rb

lib/liquid/context.rb

@@ -28,8 +28,9 @@ module Liquid
       @strainer ||= Strainer.create(self)
     end
 
-    # adds filters to this context.
-    # this does not register the filters with the main Template object. see <tt>Template.register_filter</tt>
+    # Adds filters to this context.
+    #
+    # Note that this does not register the filters with the main Template object. see <tt>Template.register_filter</tt>
     # for that
     def add_filters(filters)
       filters = [filters].flatten.compact
@@ -52,7 +53,6 @@ module Liquid
       end
     end
 
-
     def invoke(method, *args)
       if strainer.respond_to?(method)
         strainer.__send__(method, *args)
@@ -61,40 +61,41 @@ module Liquid
       end
     end
 
-    # push new local scope on the stack. use <tt>Context#stack</tt> instead
+    # Push new local scope on the stack. use <tt>Context#stack</tt> instead
     def push(new_scope={})
       raise StackLevelError, "Nesting too deep" if @scopes.length > 100
       @scopes.unshift(new_scope)
     end
 
-    # merge a hash of variables in the current local scope
+    # Merge a hash of variables in the current local scope
     def merge(new_scopes)
       @scopes[0].merge!(new_scopes)
     end
 
-    # pop from the stack. use <tt>Context#stack</tt> instead
+    # Pop from the stack. use <tt>Context#stack</tt> instead
     def pop
       raise ContextError if @scopes.size == 1
       @scopes.shift
     end
 
-    # pushes a new local scope on the stack, pops it at the end of the block
+    # Pushes a new local scope on the stack, pops it at the end of the block
     #
     # Example:
-    #
     #   context.stack do
     #      context['var'] = 'hi'
     #   end
-    #   context['var]  #=> nil
     #
+    #   context['var]  #=> nil
     def stack(new_scope={},&block)
       result = nil
       push(new_scope)
+
       begin
         result = yield
       ensure
         pop
       end
+
       result
     end
 
@@ -116,16 +117,14 @@ module Liquid
     end
 
     private
-
       # Look up variable, either resolve directly after considering the name. We can directly handle
-    # Strings, digits, floats and booleans (true,false). If no match is made we lookup the variable in the current scope and
+      # Strings, digits, floats and booleans (true,false).
+      # If no match is made we lookup the variable in the current scope and
       # later move up to the parent blocks to see if we can resolve the variable somewhere up the tree.
       # Some special keywords return symbols. Those symbols are to be called on the rhs object in expressions
       #
       # Example:
-    #
       #   products == empty #=> products.empty?
-    #
       def resolve(key)
         case key
         when nil, 'nil', 'null', ''
@@ -136,21 +135,16 @@ module Liquid
           false
         when 'blank'
           :blank?
-      when 'empty'
+        when 'empty' # Single quoted strings
           :empty?
-      # Single quoted strings
-      when /^'(.*)'$/
+        when /^'(.*)'$/ # Double quoted strings
           $1.to_s
-      # Double quoted strings
-      when /^"(.*)"$/
+        when /^"(.*)"$/ # Integer and floats
           $1.to_s
-      # Integer and floats
-      when /^(\d+)$/
+        when /^(\d+)$/ # Ranges
           $1.to_i
-      # Ranges
-      when /^\((\S+)\.\.(\S+)\)$/
+        when /^\((\S+)\.\.(\S+)\)$/ # Floats
           (resolve($1).to_i..resolve($2).to_i)
-      # Floats
         when /^(\d[\d\.]+)$/
           $1.to_f
         else
@@ -158,10 +152,10 @@ module Liquid
         end
       end
 
-    # fetches an object starting at the local scope and then moving up
-    # the hierachy
+      # Fetches an object starting at the local scope and then moving up the hierachy
       def find_variable(key)
         scope = @scopes.find { |s| s.has_key?(key) }
+
         if scope.nil?
           @environments.each do |e|
             if variable = lookup_and_evaluate(e, key)
@@ -170,27 +164,28 @@ module Liquid
             end
           end
         end
+
         scope     ||= @environments.last || @scopes.last
         variable  ||= lookup_and_evaluate(scope, key)
 
         variable = variable.to_liquid
         variable.context = self if variable.respond_to?(:context=)
+
         return variable
       end
 
-    # resolves namespaced queries gracefully.
+      # Resolves namespaced queries gracefully.
       #
       # Example
-    #
       #  @context['hash'] = {"name" => 'tobi'}
       #  assert_equal 'tobi', @context['hash.name']
       #  assert_equal 'tobi', @context['hash["name"]']
-    #
       def variable(markup)
         parts = markup.scan(VariableParser)
         square_bracketed = /^\[(.*)\]$/
 
         first_part = parts.shift
+
         if first_part =~ square_bracketed
           first_part = resolve($1)
         end
@@ -229,15 +224,15 @@ module Liquid
         end
 
         object
-    end
+      end # variable
 
       def lookup_and_evaluate(obj, key)
         if (value = obj[key]).is_a?(Proc) && obj.respond_to?(:[]=)
-        obj[key] = value.call(self)
+          obj[key] = (value.arity == 0) ? value.call : value.call(self)
         else
           value
         end
-    end
+      end # lookup_and_evaluate
 
       def squash_instance_assigns_with_environments
         @scopes.last.each_key do |k|
@@ -248,7 +243,7 @@ module Liquid
             end
           end
         end
-    end
+      end # squash_instance_assigns_with_environments
+  end # Context
 
-  end
-end
+end # Liquid