Add defaults to filters

app/controllers/categories_controller.rb

@@ -9,7 +9,7 @@ class CategoriesController < ApplicationController
   # GET /categories
   # GET /categories.json
   def index
-    @filter = ProcessorFilter.new(Category.order(name: :asc), params)
+    @filter = ProcessorFilter.new(Category.all, params, defaults: { order_by: :name, sort_by: :asc })
     authorize! @categories = @filter.results
   end
 

app/models/filter.rb

@@ -4,13 +4,24 @@
   include ActiveModel::Conversion
   extend ActiveModel::Translation
 
-  attr_reader :attribute_names
+  attr_reader :attributes, :attribute_names
 
   delegate :model_name, to: :class
 
-  def initialize(params, attribute_names)
-    @params = params.dup
+  def initialize(params, attribute_names, defaults: {})
     @attribute_names = attribute_names
+
+    params = if params.respond_to?(:permit)
+                      _compact_attributes params.permit(*_permitted_attributes_names).to_h
+                    else
+                      _compact_attributes params.with_indifferent_access
+                    end
+
+    @attributes = defaults.with_indifferent_access
+      .select { |k, v| attribute_names.include?(k.to_sym) }
+      .deep_transform_values(&:to_s)
+      .merge(params)
+            # raise
   end
 
   class << self
@@ -41,14 +52,6 @@
   def filled_attributes
     @filled_attributes ||= attributes.compact_blank
   end
-
-  def attributes
-    @attributes ||= if @params.respond_to?(:permit)
-                      _compact_attributes @params.permit(*_permitted_attributes_names).to_h
-                    else
-                      _compact_attributes @params.with_indifferent_access
-                    end
-  end
   alias to_h attributes
 
   private

app/models/processor_filter.rb

@@ -1,13 +1,13 @@
 # frozen_string_literal: true
 
 class ProcessorFilter < Filter
-  def initialize(records, params, with: nil)
+  def initialize(records, params, with: nil, defaults: {})
     @records = records
     @rubanok_class = with || guess_processor_from_records(records)
 
     raise "Processor class missing" unless @rubanok_class
 
-    super(params, @rubanok_class.fields_set.to_a)
+    super(params, @rubanok_class.fields_set.to_a, defaults:)
   end
 
   def results