Re: Add output-attributes grob property to replace id (issue 308430043 by address@hidden)

[Paul]

On 09/27/2016 02:49 PM, Urs Liska wrote:

> We will definitely want to have an 'id property to address elements from
> elsewhere in a document, be it spanners or be it edition-engraver mods
> or similar additions. Maybe in the context of partial recompilation
> features IDs may become handy. So it might be an option to leave a
> top-level 'id property in place right now instead of possibly adding it
> back at a later point?

Ok, since there's hesitation about removing it, I'll leave it in. We can 
always remove it in a follow-up patch if that is desired.  I will keep 
the convert-ly rule that rewrites ".id" to ".output-attributes.id" to 
help keep the svg functionality working for existing user files.

For the doc string I'll just use "An id string for the grob."  I'm open 
to suggestions if anyone thinks it should say more, like "not currently 
used by LilyPond".

(This brings up some thoughts I've had about supporting custom 
properties.  I'll send another email about that.)

-Paul