How do you deal with violent behaviour in public

[lisad123]

Dd2 has had a bad few weeks, and while at home when she's kicking off I can leave the room ect. But when we are out, we used to have buggy to strap her in to keep her safe, and us.
Yesterday, she really kicked off at a group and she was gunning for me. Kicking me, so removed her shoes, moved away at a safe distance, but then she was pinching me, slapping and spitting.
I should add this behaviour isn't regular for her.

She did calm down, but this took about 30 mins.
Other than restraint, what do you do?

sorry about this with my little one it always happened if she could not express herself non verbal,not feeling well and another big thing was constipation....

Not much else, other than get very good at spotting triggers before they were activated, selected my clothing and jewellery to fit the situation, use restraint and pinning when necessary and completely ignore and not worry about the observations and opinions of other people whilst the meltdown was going on.
I always went for avoidance wherever possible, even if that invited criticism from others.

I used to get this with DD1 though its fading now.
For me, the biggest factor was to completely block the judgey-pants-brigade in the background.
I used to get down to DD1's level look her in the eye, tell her that I loved her and that her behaviour was not on.
After that, she could kick away at the floor or walls, but not me. And I contained where she was threatening to run to the road/stream/carpark/whatever.
She's much better now.....but I am also much better at letting her know what is coming up and at spotting when she is getting to overload.