[PD] canvas path

[Jonathan Wilkes]

Hi Miller,
     Well, currently it works like this: "If I put my stuff in the folder with my abstraction, and the person using my abstraction doesn't happen to use [declare] to set a path containing stuff that aliases the name of my abstraction or stuff that aliases the libdir/name of my subdir/abstraction, then my abstraction will load the stuff from my folder, _except_ for cases where my folder contains an abstraction aliased by an external binary found either in the global path or the aforementioned coincidental use of [declare] in a parent patch.

The only sensible thing I can think of is giving the abstraction's directory implicit 
precedence.  "If I put my stuff in the folder with my abstraction, then 
my abstraction will load the stuff from my folder."

-Jonathan

On Monday, October 20, 2014 11:34 AM, Miller Puckette <msp at ucsd.edu> wrote:
 


Hi all,

I think it might work simply to maintain a per-patch list
 of "externs" 
currently loaded.  New patches would start out with an empty list, which would
then get filled in by that patch's own search procedures.

There might be some complicated problems to resove about such searche within
abstractions (indeed, there are already severe problems the way that is set
up that I want to try to fix.)

cheers
Miller


Oe Sun, Oct 19, 2014 at 11:21:15AM -0700, Jonathan Wilkes via Pd-list wrote:
> Hi list,
> Let me describe a typical way to use Pd:
> 1) patch author makes a patch
> 2)
>  patch author abstracts out certain functions into Pd abstractions
> 3) patch author makes a
 self-contained collection of these abstractions (and maybe some helper abstractions)
> 4) patch author takes every _reasonable_ step to make their collection portable-- that is, to ensure that their abstractions and nested abstractions create correctly on any version of Pd and don't collide with anything in the standard library path.
> 
> Currently a patch author cannot achieve this.  Pure data forces them to care about what names pre-existing externals might have (which is probably why many externals make a common name prefix part of the name of each object).  The reason is that an abstraction's directory is not the first place to be searched for externals or abstractions to be loaded.  It is superceded by the searchpath set by [declare] for all of that abstraction's parent canvases.
> 
> If any of those parent canvases declare a path which
>  has an external or abstraction by the same name as one of the helper abstractions, the object in that path will get created instead of the helper abstraction.  Furthermore, if any of those parent canvases declare a path that happens to have the same name as the subdirectory containing the helper abstraction, then "path/objectname" will override "subdirectory/helper".  This is even true if you use "./subdirectory/helper".
> 
> This means that if the patch author wants to grope toward portability they have to do this, too:
> 5) read/search all the libnames and object names in pd-extended, and all the other widely used libs and objects scattered about the internet.  Then come up with a name that is human readable, but also unique enough to prevent collisions with anything else out there.
> 
> I think #5 is unreasonable,
 especially because creating a little zipped directory with abstractions (or even externals) is such a common way of
>  making ostensibly portable libraries in Pd.  Essentially we're asking users to do their own name-mangling.
> 
> So why isn't an abstraction's directory the _first_ one to be searched by default in Pd?  I understand katja and Matt Barber's reasons for using [declare] to infect an entire running instance with different path priorities, but I think that's the exception rather than the rule.  Can we give abstraction directories precedence in the loading scheme, and maybe use a startup flag to trigger Pd's current behavior?
> 
> -Jonathan

> _______________________________________________
> Pd-list at lists.iem.at mailing list
> UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20141020/65173bba/attachment.html>