Edits how the proper typecast is retrieved from

AjaxDatatablesRails::Configuration settings.

Author: antillas21

lib/ajax-datatables-rails/base.rb

@@ -106,17 +106,6 @@ def search_condition(column, value)
       model, column = column.split('.')
       model = model.singularize.titleize.gsub( / /, '' ).constantize
 
-      # because postgresql is preferred, so that's why use VARCHAR
-      # but we we need to use CHAR typecast on mysql db adapter
-      # or maybe it should
-      #   if :pg
-      #   elsif :mysql
-      #   else
-      if config.db_adapter == :pg
-        typecast = 'VARCHAR'
-      else
-        typecast = 'CHAR'
-      end
       casted_column = ::Arel::Nodes::NamedFunction.new('CAST', [model.arel_table[column.to_sym].as(typecast)])
       casted_column.matches("%#{value}%")
     end
@@ -129,6 +118,14 @@ def aggregate_query
       conditions.compact.reduce(:and)
     end
 
+    def typecast
+      case config.db_adapter
+      when :pg then 'VARCHAR'
+      when :mysql2 then 'CHAR'
+      when :sqlite3 then 'TEXT'
+      end
+    end
+
     def offset
       (page - 1) * per_page
     end

spec/ajax-datatables-rails/ajax_datatables_rails_spec.rb

@@ -238,6 +238,49 @@ def self.arel_table
       expect(config.db_adapter).to eq(:mysql2)
     end
   end
+
+  describe '#typecast' do
+    params = {
+      :draw => '5',
+      :columns => {
+        "0" => {
+          :data => '0',
+          :name => '',
+          :searchable => true,
+          :orderable => true,
+          :search => { :value => '', :regex => false }
+        },
+        "1" => {
+          :data => '1',
+          :name => '',
+          :searchable => true,
+          :orderable => true,
+          :search => { :value => '', :regex => false }
+        }
+      },
+      :order => { "0" => { :column => '1', :dir => 'desc' } },
+      :start => '0',
+      :length => '10',
+      :search => { :value => '', :regex => false },
+      '_' => '1403141483098'
+    }
+    let(:view) { double('view', :params => params) }
+    let(:datatable) { AjaxDatatablesRails::Base.new(view) }
+
+    it 'returns VARCHAR if :db_adapter is :pg' do
+      expect(datatable.send(:typecast)).to eq('VARCHAR')
+    end
+
+    it 'returns CHAR if :db_adapter is :mysql2' do
+      allow_any_instance_of(AjaxDatatablesRails::Configuration).to receive(:db_adapter) { :mysql2 }
+      expect(datatable.send(:typecast)).to eq('CHAR')
+    end
+
+    it 'returns TEXT if :db_adapter is :sqlite3' do
+      allow_any_instance_of(AjaxDatatablesRails::Configuration).to receive(:db_adapter) { :sqlite3 }
+      expect(datatable.send(:typecast)).to eq('TEXT')
+    end
+  end
 end
 
 describe AjaxDatatablesRails do
@@ -255,4 +298,4 @@ def self.arel_table
     end
 
   end
-end
+end