My plugin is going to have a section in it's configuration that will look like this:
messages:
reload_complete: ""
line_set: "" # Local Placeholders: %line_number% %line_content%
line_removed: "" # Local Placeholders: %line_number% %line_content%
title_set: "" # Local Placeholders: %title%
board_shown: ""
board_hidden: ""
board_shown_other: ""
board_hidden_other: ""
board_shown_all: ""
board_hidden_all: ""
As you can see, there are "local placeholders", kind of like what BossShopPro has.
The PlaceholderAPI#setPlaceholders methods don't really provide a way of doing this. If I were to register my own expansion, would it be bad practice to set these local placeholders in it temporarily? If you know about Flask in Python, it will do something similar to flask.request, and it will only really work on single-threaded applications. I am thinking that this is okay with Bukkit commands as long as they are all done on one thread... but I do not know that for sure.


