Contents

# frozen_string_literal: true

require_relative '../enumerable_set_instruction'
require 'active_support/core_ext/module/delegation'

class ActiveSet
  module Filtering
    class EnumerableStrategy
      delegate :attribute_instance,
               :attribute_class,
               :attribute_value,
               :attribute_value_for,
               :operator,
               :attribute,
               to: :@set_instruction

      def initialize(set, attribute_instruction)
        @set = set
        @attribute_instruction = attribute_instruction
        @set_instruction = EnumerableSetInstruction.new(attribute_instruction, set)
      end

      def execute
        return false unless @set.respond_to? :select

        if execute_filter_operation?
          set = filter_operation
        elsif execute_intersect_operation?
          begin
            set = intersect_operation
          rescue TypeError # thrown if intersecting with a non-Array
            return false
          end
        else
          return false
        end

        set
      end

      private

      def execute_filter_operation?
        return false unless attribute_instance
        return false unless attribute_instance.respond_to?(attribute)
        return false if attribute_instance.method(attribute).arity.positive?

        true
      end

      def execute_intersect_operation?
        return false unless attribute_class
        return false unless attribute_class.respond_to?(attribute)
        return false if attribute_class.method(attribute).arity.zero?

        true
      end

      def filter_operation
        @set.select do |item|
          attribute_value_for(item)
            .public_send(
              operator,
              attribute_value
            )
        end
      end

      def intersect_operation
        other_set = attribute_class
                    .public_send(
                      attribute,
                      attribute_value
                    )
        @set & other_set
      end
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
actionset-0.8.2	lib/active_set/filtering/enumerable_strategy.rb
actionset-0.8.1	lib/active_set/filtering/enumerable_strategy.rb