Does a defendant have a right of confrontation at a formal revocation hearing?

defendant's right of confrontation at the formal revocation hearing does not arise from the confrontation clause, but from due process [citation]; it is 'not absolute. Confrontation may be denied if the trier-of-fact finds and expresses good cause for doing so.' [Citation.] For example, the former testimony of a legally unavailable witness is generally admissible. [Citation.] Due process does not prohibit the 'use where appropriate of the conventional substitutes for live testimony, including affidavits, depositions, and documentary evidence.' " (People v. Gomez (2010) 181 Cal.App.4th 1028, 1033-1034.)