[Fab-user] Re: Completed suggestion: skipping executed commands (#7)

[Niklas Lindström]

Hi again!

I have reworked the implementation of this feature (and the @depends
which use this via `invoke`). It now plays correctly with Jeff's new
"executions" algorithm. This is in part because the decorators I added
no longer creates wrapped commands, but adds a call chain which is
invoked prior to the command. This also makes it explicit in the
output when commands are chained (i.e. triggered from other commands).
(And it isolates this feature better in the `_execute_command`.)

Since as said this is a complex change, I am willing to move *all*
related code to a branch (including my decorators who add things to
this "call chain"), and use my master only for the more "conventional"
changes I hope you'll eventually accept (as per my other
"Change"-mails).

 (That way I can also experiment with alternative solutions to my
current use of @depends if you're not happy with how it works now.)

(Furthermore I can also move forward with an upcoming change I'd like
to do to make Fabric "resettable", which would make my plans for
unittests of it all much easier. This'll build on my #2 (the "managed
namspace" change) and #3 (`DEFAULT_ENV` + `Configuration`). I'll get
back to this.)

Best regards,
Niklas



On Wed, Oct 22, 2008 at 12:14 AM, Niklas Lindström <address@hidden> wrote:
> [These changes are present in my fork of Fabric at
> <http://github.com/niklasl/fabric/tree/master>]
>
>
> == 7. Skipping executed commands ==
>
> Added the `invoke` operator for prevention of multiple calls of commands.
>
> This is a somewhat invasive change, but I hope I've addressed it
> better now. Here's how it works now:
>
> My initial version only invokes a command once (unless you call it
> manually in code) at all times. Christian had a concern that this may
> play ill with at least the `set` command. I thus realized that it
> works very bad with commands that take arguments altogether.
>
> Therefore, now anything supplied on the command line is executed even
> if repeated. But *all* `_execute_command` invokations, including
> these, are remembered, *including* their arguments (see `_args_hash`).
> This is currently only used via `invoke`, which will not invoke the
> same command+args twice.
>
> (The only, in my opinion minor, "danger" is if `prompt` is used to
> possibly change a similar invocation after the command call. Since
> skips are also printed, even then the user will be notified of the
> skip.)
>
> Note: I won't object much if you find this too complex. I can then
> perhaps revert to a `call_once` (and associated `depends`) without
> support for arguments at all.. (Although I think it would be nice if
> it cooperated with the normal _execute_command.)
>
>
> ------------------------------------------
> Best regards,
> Niklas
>