(a) As soon as practicable after the commencement of an action brought as a class action, the court shall determine by order whether it is to be maintained as a class action under this subchapter.
(b) An order under this section may be altered or amended before a decision on the merits.
(c) An order determining whether the action may be maintained as a class action under this subchapter is an interlocutory order that is appealable. The procedures applicable to accelerated appeals in the Texas Rules of Appellate Procedure apply to the appeal.