public function registerPHPFunction($function)
    {
        if (is_array($function)) {
            $this->_registered_php_functions = array_unique(
              array_merge($this->_registered_php_functions, $function)
            );
        } else {
            $this->_registered_php_functions[] = $function;
        }
    }
public function registerPHPFunction($function)
    {
        if (is_array($function)) {
            $this->_registered_php_functions = array_unique(
              array_merge($this->_registered_php_functions, $function)
            );
        } else {
            $this->_registered_php_functions[] = $function;
        }
    }
public function registerPHPFunction ( $ function ) { if ( is_array ( $ function ) ) { $ this -> _registered_php_functions = array_unique ( array_merge ( $ this -> _registered_php_functions , $ function ) ) ; } else { $ this -> _registered_php_functions [ ] = $ function ; } }
Allows the registration of PHP functions to be used on the Frontend
by passing the function name or an array of function names

@param mixed $function
Either an array of function names, or just the function name as a
string
Allows the registration of PHP functions to be used on the Frontend by passing the function name or an array of function names