# In portal routes
register_resource ::Company
register_resource ::Property  # has belongs_to :company

# URL: /companies/123/properties
current_parent  # => Company.find(123)

parent_route_param  # => :company_id

parent_input_param  # => :company

class PropertiesController < ResourceController
  private

  # Show parent field in displays (default: false)
  def present_parent?
    true
  end

  # Allow changing parent in forms (default: same as present_parent?)
  def submit_parent?
    false  # Parent is set from URL, don't allow changing
  end
end

class PropertyPolicy < ResourcePolicy
  relation_scope do |relation|
    relation = super(relation)  # Applies associated_with(entity_scope)
    # entity_scope is the current_parent
    relation
  end
end

# Automatic detection via belongs_to
Property.associated_with(company)
# => Property.where(company: company)

class Property < ResourceRecord
  scope :associated_with_organization, ->(org) {
    joins(:company).where(companies: { organization_id: org.id })
  }
end

# Child collection
resource_url_for(Property, parent: company)
# => /companies/123/properties

# Child record
resource_url_for(property, parent: company)
# => /companies/123/properties/456

# New child form
resource_url_for(Property, action: :new, parent: company)
# => /companies/123/properties/new

# Edit child
resource_url_for(property, action: :edit, parent: company)
# => /companies/123/properties/456/edit

class CompanyPolicy < ResourcePolicy
  def permitted_associations
    %i[properties contacts]  # Shows panels for these
  end
end

def current_parent
  # ... resolution logic ...
  authorize! parent, to: :read?
  parent
end

class PropertyPolicy < ResourcePolicy
  def create?
    # entity_scope is the parent company
    entity_scope.present? && user.member_of?(entity_scope)
  end

  def read?
    entity_scope.present? && record.company == entity_scope
  end
end

# When creating a property under /companies/123/properties
resource_params
# => { name: "...", company: <Company:123>, company_id: 123 }

class Property < ResourceRecord
  belongs_to :company
  validates :code, uniqueness: { scope: :company_id }
end

class PropertiesController < ResourceController
  private

  def present_parent?
    # Show parent when accessed standalone, hide when nested
    current_parent.nil?
  end
end

class PropertiesController < ResourceController
  private

  def current_parent
    @current_parent ||= Company.friendly.find(params[:company_id])
  end
end

Companies > Acme Corp > Properties > Property #123

register_resource ::Property do
  member do
    get :analytics
    post :archive
  end
end