Advice on an issue with my nephew who has ASD?

I have a wonderful nephew who is a very loving, sweet boy, and tho he is not very verbal he can communicate.
One of the things that he loves is his iphone. Lately they've become an obsession of his, he's always on his phone and when they visit us or vice versa and he wants to play with our phones as well. I never had any issue with this, they seem to relax him and keep him entertained, so I would hand him my phone and let him have fun. Recently tho, he started deleting things, some of which were important, others I couldn't have cared about. After that I figured I would not bring my phone in to my sisters in laws house, and when they came over I put it up where he couldn't see it. Of course, he couldn't be fooled, he knew it was somewhere. He had a complete meltdown after I told him I didn't have it, I let him check my bag, pockets, jacket, just so he knew I didn't have it with me. However he continued crying/yelling etc until I was asked (by my mother in law) to go to the car and get my phone so he would stop. I hated seeing him so upset, and I went to the car, got my phone and let him use it. Once again, he deleted numerous things and then threw it at a wall. The issue here really isn't about my phone, after all it is just a phone. What I'm wondering is if children with Autism are supposed to be told no, or disciplined?
I guess my question is one of curiosity, are children with ASD typically told "no", are there types of discipline that should be used?

Yes they should be disciplined, but they respond better to being told yes.

instead of saying 'don't use my iPhone'

say' use your iPhone' maybe you can send him text or picture messages so he has some of the same things on his phone.

if you let him use your phone --tell him what is okay to do:
look at the pictures
play the games
make a video
take a selfie

he needs to be praised and rewarded for acting appropriately instead of punished.

when he does go to delete something, stop him and redirect him… And then praise and reward for good behavior… You would need to be supervising him with the phone.

a major issue with this incident is that it was an unexpected change… If you are going to change the rules on him--you need to give him advance notice when possible…

tell him next time, you will not have your iPhone… And remind him of this often. Maybe write it down in a social story for him… Showing you don't have the phone and what he can do instead.

possibly, he could be allowed to use your phone for a few minutes under direct supervision for good behavior during the visit… It would help to have a list of activities (look at books while adults talk, eat dinner, go for walk, etc) and in the end use your phone for 3-5 minutes…

you can use a timer--when the timer goes off phone time is done.

if he has been taught with applied behavior analysis before, he should catch on quick, but if he hasn't it will take a lot of work to get him into the routine.