Move predicate building to a stand alone PredicateBuilder class

activerecord/lib/active_record.rb

@@ -54,6 +54,7 @@ module ActiveRecord
       autoload :QueryMethods
       autoload :FinderMethods
       autoload :CalculationMethods
+      autoload :PredicateBuilder
     end
 
     autoload :Base

activerecord/lib/active_record/relation/predicate_builder.rb

@@ -0,0 +1,36 @@
+module ActiveRecord
+  class PredicateBuilder
+
+    def initialize(engine)
+      @engine = engine
+    end
+
+    def build_from_hash(attributes, default_table)
+      predicates = attributes.map do |column, value|
+        arel_table = default_table
+
+        if value.is_a?(Hash)
+          arel_table = Arel::Table.new(column, @engine)
+          build_predicate_from_hash(value, arel_table)
+        else
+          column = column.to_s
+
+          if column.include?('.')
+            table_name, column = column.split('.', 2)
+            arel_table = Arel::Table.new(table_name, @engine)
+          end
+
+          case value
+          when Array, Range, ActiveRecord::Associations::AssociationCollection, ActiveRecord::NamedScope::Scope
+            arel_table[column].in(value)
+          else
+            arel_table[column].eq(value)
+          end
+        end
+      end
+
+      predicates.flatten
+    end
+
+  end
+end

activerecord/lib/active_record/relation/query_methods.rb

@@ -104,11 +104,14 @@ module ActiveRecord
     def where(*args)
       return spawn if args.blank?
 
+      builder = PredicateBuilder.new(Arel::Sql::Engine.new(@klass))
+
       conditions = if [String, Array].include?(args.first.class)
         merged = @klass.send(:merge_conditions, args.size > 1 ? Array.wrap(args) : args.first)
         Arel::SqlLiteral.new(merged) if merged
       elsif args.first.is_a?(Hash)
-        build_predicate_from_hash(args.first)
+        attributes = @klass.send(:expand_hash_conditions_for_aggregates, args.first)
+        builder.build_from_hash(attributes, table)
       else
         args.first
       end
@@ -130,34 +133,5 @@ module ActiveRecord
       }.join(',')
     end
 
-    def build_predicate_from_hash(attributes, default_table = self.table)
-      attributes = @klass.send(:expand_hash_conditions_for_aggregates, attributes)
-
-      predicates = attributes.map do |column, value|
-        arel_table = default_table
-
-        if value.is_a?(Hash)
-          arel_table = Arel::Table.new(column, Arel::Sql::Engine.new(@klass))
-          build_predicate_from_hash(value, arel_table)
-        else
-          column = column.to_s
-
-          if column.include?('.')
-            table_name, column = column.split('.', 2)
-            arel_table = Arel::Table.new(table_name, Arel::Sql::Engine.new(@klass))
-          end
-
-          case value
-          when Array, Range, ActiveRecord::Associations::AssociationCollection, ActiveRecord::NamedScope::Scope
-            arel_table[column].in(value)
-          else
-            arel_table[column].eq(value)
-          end
-        end
-      end
-
-      predicates.flatten
-    end
-
   end
 end