Thomas played John Connor in Terminator: The Sarah Connor Chronicles from 2009 to 2009. He starred as Adam Conant from 2011 to 2012 in The Secret Circle. He starred in the 2010 remake of A Nightmare on Elm Street and in Kaboom. Dekker has also voiced the roles of Littlefoot in The Land Before Time and Fievel Mousekewitz in An American Tail. His first album Psyanotic was released in 2008. Dekker won Young Artist Awards in 2000, 2001, 2003, and 2004. He won a Young Hollywood Award in 2008.