that really depends on what you want to accomplish in a workout.
Since we generally recommend a warm-up, a complete cardio session is certainly an option. If the subsequent resistance training is mainly stabilization and strength endurance, it may fit quite nicely. If the weight workout is with heavier weights, then pre-fatiguing the body may not be a wise choice, and the cardio should be just a few minutes or should be any other form of dynamic warm-up.
Time is another consideration. Some clients want to get is all ‘done and over with’ at one point in time and chalk up cardio and weight in one session. Other want to split it.
There is no right or wrong here.