[wp-hackers] Force plugin to add code only where really needed

[mailapera]

Hi,
is there a way to do it? Almost all plugins add a bunch of css,
jquery, JS, php, ajax, meta tags all over the places in the code, even
if you need a plugin only on one single post or page. This slows down
performance and dirties the code quite a lot. Is there a way to force
a plugin, use a simple "if" statement, to detect where it is
absolutely needed and only output code on that page? I see that some
plugin developers do it, could this be implemente in the core? Thanks