2016-03-03 12:26 GMT+01:00 Nicolas Goaziou <mail@nicolasgoaziou.fr>:
Hello,


Hi Nicolas,
 
Fabrice Popineau <fabrice.popineau@gmail.com> writes:

> First, I can't find where is documented the difference between
> :EXPORT_LATEX_HEADER:
> and
> :EXPORT_LATEX_HEADER+:

See (info "(org) Property syntax").


I need to learn to read better because I didn't see that this paragraph was about it:

If you want to add to the value of an existing property, append a + to the property name.
The following results in the property var having the value “foo=1 bar=2”.
#+PROPERTY: var foo=1
#+PROPERTY: var+ bar=2 



> Second, when I use several lines with
> :EXPORT_LATEX_HEADER+:
> they  are concatenated into a single line.

Correct.

> This is annoying because:
>
> :PROPERTIES:
> :EXPORT_LATEX_HEADER+: \usepackage{mathptmx} % rm & math
> :EXPORT_LATEX_HEADER+: \usepackage[scaled=0.90]{helvet} % ss
> ...
> :END:
>
> results in
>
> \usepackage{mathptmx} % rm & math  \usepackage[scaled=0.90]{helvet} % ss
>
> which is obviously unintended.
>
> Could it be possible to add a '\n' between those lines?

Not quite what you are asking for, but couldn't you simply not comment
each line?

Yes, I can remove the comments, however, from time to time, it may be useful to be able to comment
some \usepackage line, and I don't see how it can be done in Org, except by killing the whole line.
 
In org reference, 12.7.2, it is said that:

‘LATEX_HEADER’
Arbitrary lines added to the preamble of the document, before the ‘hyperref’
settings. The location can be controlled via org-latex-classes.

Note the plural to lines. How can several lines be specified? AFAICS, if I do :

:EXPORT_LATEX_HEADER: \usepackage{mathptmx} % rm & math
:EXPORT_LATEX_HEADER: \usepackage[scaled=0.90]{helvet} % ss

The second line will take precedence over the first one.

Thanks for your help,

Fabrice