Adapter specific importing

lib/tire/model/import.rb

@@ -13,15 +13,84 @@ module Import
 
       module ClassMethods
 
-        def import options={}, &block
+        def import options = {}, &block
+
           options = { :method => 'paginate' }.update options
+          options[:per_page] ||= 1000
+
+          # Lets support multiple ORM's
+          if defined?(ActiveRecord) && klass.ancestors.include?(::ActiveRecord::Base) # Active Record
+            extend ActiveRecord
+          elsif defined?(Mondgoid::Document) && klass.ancestors.include?(::Mongoid::Document) # Mongoid
+            extend Mongoid
+          elsif defined?(Kaminari) && klass.respond_to?(:page) # Kaminari
+            extend Kaminari
+          elsif defined?(WillPaginate) && klass.respond_to?(:paginate)  # Will Paginate
+            extend WillPaginate
+          else
+            extend Index
+          end
+
+          import options, &block
+
+        end
+
+      end
+
+      module ActiveRecord
+        def import options={}, &block
           index   = options[:index] ? Tire::Index.new(options.delete(:index)) : self.index
-          index.import klass, options, &block
+          klass.find_in_batches(batch_size: options[:per_page]) do |group|
+            index.import group, options, &block
+          end
         end
+      end
 
+      module Mongoid
+        def import options={}, &block
+          index   = options[:index] ? Tire::Index.new(options.delete(:index)) : self.index
+          0.step(klass.count, options[:per_page]) do |offset|
+            items = klass.limit(options[:per_page]).skip(offset)
+            index.import items, options, &block
+          end
+        end
       end
 
-    end
+      module Kaminari
+        def import options={}, &block
+          index   = options[:index] ? Tire::Index.new(options.delete(:index)) : self.index
+          current = 0
+          page = 1
+          while current < klass.count
+            items = klass.page(page).per(options[:per_page])
+            index.import items, options, &block
+            current = current + items.size
+            page += 1
+          end
+        end
+      end
+
+      module WillPaginate
+        def import options={}, &block
+          index   = options[:index] ? Tire::Index.new(options.delete(:index)) : self.index
+          current = 0
+          page = 1
+          while current < klass.count
+            items = klass.paginate(page: page, per_page: options[:per_page])
+            index.import items, options, &block
+            current += items.size
+            page += 1
+          end
+        end
+      end
+
+      module Index
+        def import options={}, &block
+          index   = options[:index] ? Tire::Index.new(options.delete(:index)) : self.index
+          index.import klass, options, &block
+        end
+      end
 
+    end
   end
 end