A state lawmaker says he was assaulted outside a Dartmouth elementary school last weekend and has filed a complaint with police. Representative Christopher Markey, Democrat of Dartmouth, said the assault Saturday morning left him hospitalized. He would not discuss the nature of his injuries or the circumstances that led to the incident. Police Chief Timothy Lee told The Standard-Times that Markey was pushed after a confrontation with another man while there was a youth basketball game in the school. Markey, however, said the alleged assault involved ‘‘more than a push,’’ based on his two-day stay in the hospital and the nature of his injuries.