Add AjaxDatatablesRails::Base#column_id and AjaxDatatablesRails::Base#column_data methods

These helper methods help to retrieve:
* column id from view_columns hash for the named column
* column search value for the named column

Author: n-rodriguez

lib/ajax-datatables-rails/base.rb

@@ -111,6 +111,15 @@ def global_search_delimiter
       GLOBAL_SEARCH_DELIMITER
     end
 
+    def column_id(name)
+      view_columns.keys.index(name.to_sym)
+    end
+
+    def column_data(column)
+      id = column_id(column)
+      params.dig('columns', id.to_s, 'search', 'value')
+    end
+
     def raw_records_error_text
       <<-ERROR
 

spec/ajax-datatables-rails/base_spec.rb

@@ -222,6 +222,25 @@ def paginate_records(records)
           expect(datatable.datatable.send(:per_page)).to eq(20)
         end
       end
+
+      describe '#column_id' do
+        let(:datatable) { ComplexDatatable.new(sample_params) }
+
+        it 'should return column id from view_columns hash' do
+          expect(datatable.send(:column_id, :username)).to eq(0)
+          expect(datatable.send(:column_id, 'username')).to eq(0)
+        end
+      end
+
+      describe '#column_data' do
+        let(:datatable) { ComplexDatatable.new(sample_params) }
+        before { datatable.params[:columns]['0'][:search][:value] = 'doe' }
+
+        it 'should return column data from params' do
+          expect(datatable.send(:column_data, :username)).to eq('doe')
+          expect(datatable.send(:column_data, 'username')).to eq('doe')
+        end
+      end
     end
   end
 end