Integrate "@a", "@p" e.t.c in values section of the httpsend command

[DNAmaster10]

@A should insert a list of online players into the values section of the httpsend command.

@p should insert the name of the closest player to the sender (e.g a command block) into the value section.

[Dinty1]

There is slightly more to this. Ideally arguments would also be supported within these selectors, for which there would hopefully be a library already in existence. https://minecraft.fandom.com/wiki/Target_selectors

[DNAmaster10]

I've started implementing some basic selector features. Currently, @A should be possible for display names, actual names and UUIDs. Will publish and update documentation when completed.

[DNAmaster10]

The general idea for how this will work is users will insert a special selector with parameters into their command. This will look something like this:

/httpsend POST https://10.8.1.1:80 data=Hey!-#-Players:-#-|@a:displayNames|

Upon execution, the plugin will first replace all the space characters, so the data string will look like this:
data=Hey! Players: |@a:displayNames|

Then, anything between the "|" symbols will be replaced with whatever it's asking for. The above will be an @A selector which returns all player display names separated by a comma.

So following the selectors being replaced, it might look like:
data=Hey! Players: jim_bob,notch

It will also be possible to escape the "|" symbols by adding a "\".