lib/left_joins.rb in left_joins-1.0.1 vs lib/left_joins.rb in left_joins-1.0.2

@@ -1,33 +1,47 @@
 require "left_joins/version"
 require 'active_record'
 require 'active_record/relation'
 
-module ActiveRecord::QueryMethods
+module LeftJoins
   IS_RAILS3_FLAG = Gem::Version.new(ActiveRecord::VERSION::STRING) < Gem::Version.new('4.0.0')
-  if IS_RAILS3_FLAG
+end
+
+module ActiveRecord::QueryMethods
+
+  # ----------------------------------------------------------------
+  # ● Implement check_if_method_has_arguments! method for Rails 3
+  # ----------------------------------------------------------------
+  if LeftJoins::IS_RAILS3_FLAG
     def check_if_method_has_arguments!(method_name, args)
       if args.blank?
         raise ArgumentError, "The method .#{method_name}() must contain arguments."
       end
     end
   end
   if not method_defined?(:left_outer_joins!)
+    # ----------------------------------------------------------------
+    # ● Storing left joins values into @left_outer_joins_values
+    # ----------------------------------------------------------------
+    attr_accessor :left_outer_joins_values
     def left_outer_joins(*args)
       check_if_method_has_arguments!(:left_outer_joins, args)
 
       args.compact!
       args.flatten!
 
-      return (IS_RAILS3_FLAG ? clone : spawn).left_outer_joins!(*args)
+      return (LeftJoins::IS_RAILS3_FLAG ? clone : spawn).left_outer_joins!(*args)
     end
 
     def left_outer_joins!(*args)
       (@left_outer_joins_values ||= []) << args
       self
     end
 
+    # ----------------------------------------------------------------
+    # ● Implement left joins when building arel
+    # ----------------------------------------------------------------
     alias_method :left_joins, :left_outer_joins
     alias_method :build_arel_without_outer_joins, :build_arel
     def build_arel(*args)
       arel = build_arel_without_outer_joins(*args)
       build_left_outer_joins(arel, @left_outer_joins_values.flatten) if @left_outer_joins_values
@@ -53,11 +67,11 @@
       end
       alias_method :left_outer_joins, :left_joins
     end
 
     class ::ActiveRecord::Associations::JoinDependency
-      if IS_RAILS3_FLAG
+      if LeftJoins::IS_RAILS3_FLAG
         alias_method :build_without_hooking_join_type, :build
         def build(associations, parent = nil, join_type = Arel::Nodes::InnerJoin)
           join_type = Thread.current.thread_variable_get :left_joins_join_type || join_type
           return build_without_hooking_join_type(associations, parent, join_type)
         end
@@ -74,11 +88,11 @@
       def perform_calculation(operation, column_name, options = {})
         operation = operation.to_s.downcase
 
         # If #count is used with #distinct (i.e. `relation.distinct.count`) it is
         # considered distinct.
-        distinct = IS_RAILS3_FLAG ? options[:distinct] || self.uniq_value : self.distinct_value
+        distinct = LeftJoins::IS_RAILS3_FLAG ? options[:distinct] || self.uniq_value : self.distinct_value
 
         if operation == "count"
           column_name ||= select_for_count
           column_name = primary_key if column_name == :all && distinct
           distinct = nil if column_name =~ /\s*DISTINCT[\s(]+/i
@@ -92,5 +106,35 @@
       end
     end
   end
 end
 
+# ----------------------------------------------------------------
+# ● Implement left joins when merging relations
+# ----------------------------------------------------------------
+if not LeftJoins::IS_RAILS3_FLAG
+  require 'active_record/relation/merger'
+  class ActiveRecord::Relation
+    class Merger
+      alias_method :merge_without_left_joins, :merge
+      def merge
+        values = other.left_outer_joins_values
+        relation.left_outer_joins!(*values) if values.present?
+        return merge_without_left_joins
+      end
+    end
+  end
+
+  module ActiveRecord
+    module SpawnMethods
+
+      private
+
+      alias_method :relation_with_without_left_joins, :relation_with
+      def relation_with(values) # :nodoc:
+        result = relation_with_without_left_joins(values)
+        result.left_outer_joins_values = self.left_outer_joins_values
+        return result
+      end
+    end
+  end
+end