def update_doctype_attributes new_doctype
if new_doctype && new_doctype != @attributes['doctype']
attrs = @attributes
current_doctype = attrs['doctype']
current_backend = attrs['backend']
current_basebackend = attrs['basebackend']
if current_doctype
attrs.delete %(doctype-#{current_doctype})
attrs.delete %(backend-#{current_backend}-doctype-#{current_doctype}) if current_backend
attrs.delete %(basebackend-#{current_basebackend}-doctype-#{current_doctype}) if current_basebackend
end
attrs['doctype'] = new_doctype
attrs[%(doctype-#{new_doctype})] = ''
attrs[%(backend-#{current_backend}-doctype-#{new_doctype})] = '' if current_backend
attrs[%(basebackend-#{current_basebackend}-doctype-#{new_doctype})] = '' if current_basebackend
@doctype = nil
end
end