Re: property searches for #+CATEGORY

[Bastien <bzg@altern.org>]

Adam Spiers <orgmode@adamspiers.org> writes:

>> This would let you restrict any agenda search to a group of agenda
>> files.  I don't want to digg too far in this direction, but I think
>> there are a few other things for which such groups might be useful 
>> (e.g. publish agenda files per group...)
>
> Well, the documentation says
>
>    The category is a broad label assigned to each agenda item.  By
>    default, the category is simply derived from the file name, [...]
>
> so I thought this use case was pretty much exactly what it was
> intended for.

Lets say that #+CATEGORY is more oriented toward files grouping, and
:CATEGORY: is more oriented toward tasks grouping.  In fact, when using
several #+CATEGORY in the same file (as it is *not* recommended to do),
you are virtually splitting your file into several files, each of them
corresponding to a category.

Your request  was to be able to perform a search using #+CATEGORY as a
way to search through multiple files.  

I can see to ways of doing this:

1. implicitely add the #+CATEGORY value of a file to each entry in this
   file, and search through files having the same #+CATEGORY;

2. clearly separate the group of files from the group of tasks, and
   perform a group-restricted search.

I think (1) is problematic: what if a file has a top #+CATEGORY and
several :CATEGORY: properties?  What about precedence and inheritance?
How to build the search string if we want to search through several
:CATEGORY: properties in a single #+CATEGORY ?

> No, I don't think it's #+CATEGORY per se which is only there for
> backward compatibility - it's using it multiple times within a single
> file.

The fact that only *one* instance of #+CATEGORY is allowed in a file
calls itself for the divorce between #+CATEGORY (possibly renamed as
#+GROUP) and the :CATEGORY: property...

>> It's not that easy for users to understand how to user categories, 
>> and staying with two ways of setting them might be confusing IMO.
>
> Surely this is an argument against introducing yet another grouping
> mechanism!  We already have tags, properties, and categories.

But a category is just a property, even if the search interface raises
this property above others.  And besides these search considerations, I
really believe that having several groups of agenda-files would help.

> I already have too many problems keeping a good work/life balance! ;-)

Com'on, our daily brain-sport is to feed this list! :)

-- 
Bastien