WIP: reduce stack buffer usage for AudioReactive settings page

[softhack007]

Currently we cannot add any more options to the AudioReactive settings page, as the buffer used by oappend() is very limited and cannot be expanded any more (its placed into the task stack, not into the heap ... for historical reasons and to help tiny 8266).

This is an attempt to work around the problem, by shortening the strings that are passed into oappend(). A typical call looks like this: oappend(SET_F("dd=addDropdown('AudioReactive','config:AGC');"));. We can shorten the JS function names like this

• adI = addInfo
• adD = addDropdown
• adO = addOption
• adF = addField

before: String buffer usage: 3540 of 3871 bytes
after: String buffer usage: 3158 of 3871 bytes
==> 382 bytes saved

Actually its even possible to save more buffer space, if "AudioReactive" gets replaced by "AR": String buffer usage: 2784 of 3871 bytes
==> another 368 bytes of potential savings

To be discussed:
a) depending on predefined PINs from the buildenv, stack buffer usage can be bigger because descriptions get longer.
b) source code is harder to read after replacing names; so maybe better that oappend() peforms the replacement behind the scenes, without needing to modify audioreactive code.
c) Changing "AudioReactive" to "AR" in parameters causes problems in other areas; so maybe that could be another behind-the-scenes optimimization done by oappend. It would then need to be "undone" in the JS part, so that parameters with "AR" become "AudioReactive" again.

actually for point c) i don't have an idea for implementation yet - I'm still a "hobby coder" when it comes to JavaScript 😅

@netmindz, @ewoudwijma and other devs: I would be happy to get your opinions, ideas, and possible alternatives.
Right now we are at the limits and cannot add new options to the AudioReactive settings page any more.

[netmindz]

I didn't know what oappend was limited in length.

Definitely agree that shortening the names makes it harder to understand what is going on, it's already pretty difficult.

Use of more user friendly constants who's value contains the shorter name sounds like a good compromise.

In order to not break people's existing config files we would definitely need to swap to the longer name when saving /loading the config

[softhack007]

Note to self:

• use "A~" instead of "Audioreactive", but only in the short-named functions (see first post).
• The short functions will then expand (replace) any "A~" inside parameter strings back to "Audioreactive".

-> Fully transparent, and no problems with user settings or anything.

[ewoudwijma]

Sounds good! Shouldn't we do it consistently for all usermods?
Maybe use a 2 or 3 letter abbreviation?

[softhack007]

Sounds good! Shouldn't we do it consistently for all usermods?
Maybe use a 2 or 3 letter abbreviation?

Indeed this would be good. On the c++ side, we could do the replacement "behind the scenes" inside oappend(). On the JS side, String replace() could be used for "unpacking" abbreviations.

https://www.w3schools.com/jsref/jsref_replace.asp

[softhack007]

oappend(SET_F("dd=addDropdown('AudioReactive','config:AGC');"));. We can shorten the JS function names like this

• adI = addInfo
• adD = addDropdown
• adO = addOption
• adF = addField

The principle of this PR seems good, however in the next days I'll do a fresh restart using latest MDev.