Re: [O] [patch] Support CUSTOM_ID property in latex export

[Nicolas Goaziou]

Hello,

Richard Lawrence <address@hidden> writes:

> 1) Sometimes I need to refer to a section from within an embedded LaTeX
> block.  In that case, I need to know the appropriate label to use at the
> LaTeX level, not just in Org.  For example:
>
> * A headline
>   :PROPERTIES:
>   :CUSTOM_ID: sec:a-headline
>   :END:
>
> # ... stuff ...
>
> #+BEGIN_LATEX
> % ... more stuff ...
> (see section~\ref{sec:a-headline})
> #+END_LATEX

I don't think this is a good idea, as the character set allowed in
\label{...} macros is only a subset of the character set allowed in
custom id value. Hence the `org-export-solidify-link-text' function.

If you are cautious, this will not be a problem, but it could bite users
with little LaTeX knowledge.

> This is not possible with the present section labeling in LaTeX export,
> because I have no way of forcing Org to use a particular label for a
> section.

  * A headline
    #+latex: \label{my-section}

    #+BEGIN_LATEX
    % ... more stuff ...
    (see section~\ref{my-section})
    #+END_LATEX

It also seems more consistent to me: since you want to explicitly write
the \ref{...}, you are also expected to explicitly write the \label{...}
part.

> 2) I hope this doesn't happen, but there may come a time when I need to
> move away from Org and just use straight LaTeX.  Having control over the
> labeling will make this transition much easier, because it means I won't
> have to worry about manually changing the labels in a long document from
> Org's default "sec-..." numbering to my own semantic labels.

See above. You can even automate that with a hook (i.e., get the custom
id value and add a corresponding label at the beginning of the
headline).

> 3) This will make the LaTeX exporter's behavior more consistent with the
> HTML exporter's behavior.  The HTML exporter will use CUSTOM_ID if it is
> supplied to construct the id attributes of headlines and divs.  If
> someone is relying on this behavior of the HTML exporter, they might be
> unpleasantly surprised by the LaTeX exporter's behavior.

One relying on an implementation detail instead of the actual
specifications has to be prepared for surprises.

What do you think?


Regards,

-- 
Nicolas Goaziou