New group scoped #blank? and #present? which simply checks if the pro…

…xy owner has a group set.

This allows us to tune the SQL generated to IN statements only when needed, even if a grouped
scope is being used.

CHANGELOG

@@ -7,6 +7,10 @@
 
 * The group object is now an ActiveRecord::Relation so you can further scope it.
 
+* New group scoped #blank? and #present? which simply checks if the proxy owner has a group set.
+  This allows us to tune the SQL generated to IN statements only when needed, even if a grouped 
+  scope is being used.
+
 * New group.ids_sql which is an Arel SQL literal. Avoids large groups IDs and better query plans.
 
 

lib/grouped_scope/arish/associations/association_scope.rb

@@ -48,7 +48,11 @@ def add_constraints(scope)
             if reflection == chain.last
               # GroupedScope changed this line.
               # scope = scope.where(table[key].eq(owner[foreign_key]))
-              scope = scope.where(table[key].in(owner.group.ids))
+              scope = if owner.group.present?
+                        scope.where(table[key].in(owner.group.ids))
+                      else
+                        scope.where(table[key].eq(owner[foreign_key]))
+                      end
 
               if reflection.type
                 scope = scope.where(table[reflection.type].eq(owner.class.base_class.name))

lib/grouped_scope/self_grouping.rb

@@ -17,6 +17,14 @@ def initialize(proxy_owner)
       @proxy_owner = proxy_owner
     end
 
+    def blank?
+      proxy_owner.group_id.blank?
+    end
+
+    def present?
+      !blank?
+    end
+
     def ids
       grouped_scoped_ids.map(&primary_key.to_sym)
     end
@@ -64,17 +72,13 @@ def grouped_proxy
       @grouped_proxy ||= grouped_scoped
     end
 
-    def grouped?
-      proxy_owner.group_id.present?
-    end
-
     def all_grouped?
       proxy_owner.all_grouped? rescue false
     end
 
     def grouped_scoped
       return proxy_class.scoped if all_grouped?
-      proxy_class.where grouped? ? arel_group_id.eq(proxy_owner.group_id) : arel_primary_key.eq(proxy_owner.id)
+      proxy_class.where present? ? arel_group_id.eq(proxy_owner.group_id) : arel_primary_key.eq(proxy_owner.id)
     end
 
     def grouped_scoped_ids

test/grouped_scope/has_many_test.rb

@@ -8,13 +8,20 @@ class GroupedScope::HasManyTest < GroupedScope::TestCase
       @employee = FactoryGirl.create(:employee)
     end
 
-    it 'scope existing association to owner' do
+    it 'scopes existing association to owner' do
       assert_sql(/"employee_id" = #{@employee.id}/) do
         @employee.reports(true)
       end
     end
 
-    it 'scope group association to group' do
+    it 'scopes group association to owner when no group present' do
+      assert_sql(/"employee_id" = #{@employee.id}/) do
+        @employee.group.reports(true)
+      end
+    end
+
+    it 'scopes group association to owner when group present' do
+      @employee.update_attribute :group_id, 43
       assert_sql(/"employee_id" IN \(#{@employee.id}\)/) do
         @employee.group.reports(true)
       end
@@ -110,7 +117,14 @@ class GroupedScope::HasManyTest < GroupedScope::TestCase
       end
     end
 
-    it 'scope group association to group' do
+    it 'scope group association to owner, since no group is present' do
+      assert_sql(/"legacy_reports"."email" = '#{@employee.id}'/) do
+        @employee.group.reports(true)
+      end
+    end
+
+    it 'scopes group association to owners group when present' do
+      @employee.update_attribute :group_id, 43
       assert_sql(/"legacy_reports"."email" IN \('#{@employee.id}'\)/) do
         @employee.group.reports(true)
       end

test/grouped_scope/self_grouping_test.rb

@@ -34,6 +34,21 @@ class GroupedScope::SelfGrouppingTest < GroupedScope::TestCase
       end
     end
 
+    it 'allows you to ask if the group is present' do
+      @employee.update_attribute :group_id, 28
+      assert_no_queries do
+        assert @employee.group_id.present?
+        assert @employee.group.present?
+      end
+    end
+
+    it 'allows you to ask if the group is blank' do
+      assert_no_queries do
+        assert @employee.group_id.blank?
+        assert @employee.group.blank?
+      end
+    end
+
     describe 'for #with_reflection' do
 
       before { @reflection = Employee.reflections[:reports] }