Mario-Like Semisolid / One Way platform

[BJC95]

I'm making a platformer game, and want to have a one way platform that allows you to jump up through it, but not fall back down.
I was thinking on using a tag on a collision box and having the player only collide with boxes with that tag when they fall down (when the player's yVol var is <= 0), but I cannot figure out how to check a collision box for a tag and apply that logic...
Any help would be appreciated, I can't for the life of me figure this out.

[nightm4re94]

I think your best bet would be to override canCollideWith on your player or your platform, and simply add your y velocity check condition to determine whether the collision is valid or not.
I don't think it makes a huge difference whether that code would be in the player or the platform class.