Merge pull request #264 from GUI/offset

Fix erroneous offset/start behavior

lib/ajax-datatables-rails/datatable/datatable.rb

@@ -56,7 +56,7 @@ def paginate?
       end
 
       def offset
-        (page - 1) * per_page
+        options.fetch(:start, 0).to_i
       end
 
       def page

spec/ajax-datatables-rails/base_spec.rb

@@ -155,10 +155,10 @@
           expect(datatable.datatable.send(:offset)).to eq(0)
         end
 
-        it 'matches the value on view params[:start] minus 1' do
+        it 'matches the value on view params[:start]' do
           paginated_view = double('view', params: { start: '11' })
           datatable = described_class.new(paginated_view)
-          expect(datatable.datatable.send(:offset)).to eq(10)
+          expect(datatable.datatable.send(:offset)).to eq(11)
         end
       end
 

spec/ajax-datatables-rails/datatable/datatable_spec.rb

@@ -73,7 +73,7 @@
     end
 
     it 'offset' do
-      expect(datatable.offset).to eq(45)
+      expect(datatable.offset).to eq(50)
     end
 
     it 'page' do

spec/ajax-datatables-rails/orm/active_record_paginate_records_spec.rb

@@ -38,16 +38,16 @@
       if AjaxDatatablesRails.config.db_adapter.in? %i[oracle oracleenhanced]
         if Rails.version.in? %w[4.0.13 4.1.16 4.2.10]
           expect(datatable.paginate_records(records).to_sql).to include(
-            'rownum <= 50'
+            'rownum <= 51'
           )
         else
           expect(datatable.paginate_records(records).to_sql).to include(
-            'rownum <= (25 + 25)'
+            'rownum <= (26 + 25)'
           )
         end
       else
         expect(datatable.paginate_records(records).to_sql).to include(
-          'LIMIT 25 OFFSET 25'
+          'LIMIT 25 OFFSET 26'
         )
       end
     end