Improve variable naming and counting

lib/data_tables/active_model_serializers/adapter/pagination.rb

@@ -12,7 +12,7 @@ def initialize(serializer)
         def as_h
           {
             recordsTotal: collection&.total_entries&.to_i,
-            recordsFiltered: @collection&.unscope(:limit, :offset)&.count_estimate&.to_i
+            recordsFiltered: collection&.unscope(:limit, :offset)&.count_estimate&.to_i
           }
         end
 

lib/data_tables/modules/pagination.rb

@@ -5,35 +5,42 @@ module Modules
     class Pagination
       FIRST_PAGE = 1
 
-      attr_reader :collection, :context
+      attr_reader :original_scope, :filtered_scope, :context
 
-      def initialize(collection, request_parameters)
-        @collection = collection
+      def initialize(original_scope, filtered_scope, request_parameters)
+        @original_scope = original_scope
+        @filtered_scope = filtered_scope
         @request_parameters = request_parameters
       end
 
       def paginate
         start = (@request_parameters[:start] || '0').to_i
         length = (@request_parameters[:length] || '10').to_i
         page = (start / length) + 1
-        @collection = @collection.paginate(page: page, per_page: length, total_entries: records_total)
+        @filtered_scope = @filtered_scope.paginate(page: page, per_page: length, total_entries: records_total)
       end
 
       def as_json
         {
-          recordsTotal: @collection&.total_entries&.to_i,
+          recordsTotal: @filtered_scope&.total_entries&.to_i,
           recordsFiltered: records_filtered&.to_i
         }
       end
 
       protected
 
       def records_total
-        @collection&.model&.all.count_estimate
+        # TODO: Check threshold
+        count_estimate = @original_scope&.model&.all&.count_estimate.to_i
+        if count_estimate < 1_000_000
+          count_estimate = @original_scope&.count
+        end
+
+        count_estimate
       end
 
       def records_filtered
-        @collection&.unscope(:limit, :offset)&.count_estimate
+        @filtered_scope&.unscope(:limit, :offset)&.count_estimate
       end
 
       attr_reader :adapter_options

lib/data_tables/responder.rb

@@ -9,29 +9,29 @@
 module DataTables
   module Responder
 
-    def self.respond(resource, params)
-      model = resource.try(:model) || resource
+    def self.respond(original_scope, params)
+      model = original_scope.try(:model) || original_scope
 
-      results = resource
+      filtered_results = original_scope&.dup || model.none
       hashed_orders = transmute_datatable_order(params[:order], params[:columns])
       orders = flat_keys_to_nested hashed_orders
 
       order_by = orders.collect do |k, order|
         if order.is_a? Hash
           if (klass = model.reflect_on_association(k).try(:klass))
-            results = results.joins(k)
+            filtered_results = filtered_results.joins(k)
             klass.arel_table[order.first.first].send(order.first.last)
           end
         else
           { k => order }
         end
       end
 
-      results = search(results, params)
+      filtered_results = search(filtered_results, params)
 
       # Rails.logger.warn "SEARCH BY: #{search_by}"
-      results = order_by.inject(results) { |r, o| r.order(o) }
-      results = paginate(results, params)
+      filtered_results = order_by.inject(filtered_results) { |r, o| r.order(o) }
+      filtered_results = paginate(original_scope, filtered_results, params)
     end
 
     def self.flat_keys_to_nested(hash)
@@ -43,12 +43,12 @@ def self.flat_keys_to_nested(hash)
     end
 
 
-    def self.paginate(collection, params)
-      Modules::Pagination.new(collection, params).paginate
+    def self.paginate(original_scope, filtered_results, params)
+      Modules::Pagination.new(original_scope, filtered_results, params).paginate
     end
 
-    def self.search(collection, params)
-      Modules::Search.new(collection, params).search
+    def self.search(filtered_results, params)
+      Modules::Search.new(filtered_results, params).search
     end
 
     def self.transmute_datatable_order(orders, columns)

lib/data_tables/responder/version.rb

@@ -1,5 +1,5 @@
 module DataTables
   module Responder
-    VERSION = '0.3.0'
+    VERSION = '0.3.1'
   end
 end