Coding a retest, whats standard method?

So I have a strategy that is reading levels but I want to enter on a retest as in touch it then continue. what is a good method for doing this?

Currently im just setting a buy order at that level with a stop loss. I would like to find ways of entering after a touch and reversal or something. Any thoughts on techniques for sort of thing ?

If there are sources for education on this portion of algo i would also be interested.