Re: Finder Extensions

[uerics@mcl.ucsb.edu (Eric D. Shepherd)]

Here's how Finder Extensions work:

When your system starts up, any Finder Extensions (aka INITs) in your boot
volume's System.Setup folder are executed.  They install a request
procedure, which the Finder can access to tell the Finder Extension to do
various things.

When the Finder starts up, it loads all the Finder Extensions in the
FinderExtras folder located in the _same directory_ as the Finder was
launched from.  Normally this is the boot volume's System/FinderExtras
folder.

When the Finder shuts down, either to launch another application or to
shut down the system (Apple-Q), it notifies all the Finder Extensions that
were loaded by the Finder (the only ones it knows about) that they need to
shut down.  The Finder then unloads all the Finder Extensions that it
loaded from FinderExtras, thus freeing up memory for other applications to
use.

Finder Extensions that were located in System.Setup, though, _never_ get
unloaded, since the Finder doesn't know about them.

Finder Extensions communicate with the Finder indirectly, following a
specific set of instructions.  That's why Finder Extensions are so
versatile -- the Finder simply doesn't need to know anything about them.
Finder Extensions can be NDAs, INITs, or "pure" Finder Extensions.

I don't know if this makes things any clearer.  Heck, I still get a little
confused by it all.  Some of the stuff I just described I just found out
about last night. :)

- Eric S.

--
Eric D. Shepherd                   | Apple II Alliance Charter Member
InterNet: uerics@mcl.mcl.ucsb.edu  |           ACM Member
FidoNet:  1:206/2713 Eric Shepherd | Programming Law #1: "When in
AOL:      Sheppy                   | doubt, rewrite from scratch."