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