openproject/modules/costs/app/models/work_package/material_costs.rb

class WorkPackage
  class MaterialCosts < AbstractCosts
    def costs_model
      CostEntry
    end

    def filter_authorized(scope)
      CostEntry.with_visible_costs_on scope
    end

    def costs_sum_alias
      'cost_entries_sum'
    end

    def subselect_alias
      'cost_entries'
    end
  end
end