@PowerGlove please chip in. Could the forum display current BTC price when you swipe the mouse cursor over a word that contains a unique piece of code? As an example, we can use the proposed $BTC. Is that or something similar doable?
Yep, I could do something like that. Not sure if it's a good idea though...
I don't always follow my own advice, but when I remember to, I like thinking of forum patches in terms of niftiness vs. usefulness, and then weighing the engineering effort (and maintenance burden) against that. OP's suggestion/idea (while appreciated) scores pretty poorly when looked at this way. That is, it both leans left on the nifty vs. useful scale, and it leans left on the messy-to-implement vs. easy-to-implement scale. The best feature suggestions lean right on both scales (that is, they're legitimately useful
and don't add much complexity to the codebase). The next best kind are right-left (that is, they're useful, but might not admit a simple implementation). The worst kind are left-left (nifty rather than useful, and tricky to implement).
Lack of genuine usefulness aside (IMHO, of course), OP's idea is tricky to implement because it involves complicating SMF's message parsing code (which is already pretty hairy) with new syntax. Thinking in terms of the existing BBCode syntax would lead to a cleaner patch. So, OP's idea would be easier to implement if the proposal was to add a new BBCode tag, like:
[coin]BTC[/coin].
However, if
[coin]BTC[/coin] simply resolves to the same thing (for example) that
[url=https://coinmarketcap.com/currencies/bitcoin/]BTC[/url] would have, then its primary advantage (besides being able to switch out providers, I suppose) is brevity, and I don't think that's important enough to automatically link to some third party. If remembering (and typing out) longish BBCode sequences turns out to be at the heart of the problem statement, then I'd rather tackle that by adding a customizable "snippet" system to the BBCode editor, so that frequently used BBCode templates can be inserted easily (that would also address one of LoyceV's requests for a "split quote" feature that quickly inserts
[/quote][quote], and it would probably find many other uses, too).
Another way to go (if we just concern ourselves with bitcoin, and with showing information directly) would be to modify the existing
[btc] tag, so that in addition to rendering a little bitcoin symbol, it also displays the current price (and maybe other details) on mouse hover. (I still think that's probably more nifty than truly useful, though.)