Robert Klein <roklein <at> roklein.de> writes:
>
> Hi,
>
> is there a way, to read header arguments to source blocks in the
> exporters org-<exporter>-src-block funktions?
Not directly. org-babel-exp-code has no provision for headers.
They get dropped.
>
> E.g. is there a way to access :firstline in the example below?
>
Not exactly, but ...
If you precede the code block with
#+attr_firstline: 23
then with point in the src block
(org-element-property :attr_firstline (org-element-context))
will return ("23"). And org-*-src-block functions can use it.
If you really want to use the :firstline idiom, you can add a hook in
`org-export-before-processing-hook' to find :firstline headers and
insert #+attr_firstline lines in the buffer copy that the exporter is using.
> #+begin_src c++ -n :firstline 23
> static struct
> {
> char *entity;
> unsigned char equiv;
> } entities[] =
> {
> { "lt", '<' } ,
> { "gt", '>' } ,
> { "amp", '&' } ,
> { "quot", '"' } ,
> { "trade", 153 } , /* trade mark */
> #+end_src
>
> I didn't find it in the `element' structure.
>
> However, if I use
>
> #+begin_src c++ firstline=23
> // random C++
> #+end_src
>
> I could access :parameters from `element' and parse the string.
> However I'm not sure if I'd break some babel stuff or not.
>
C-c C-v C-i on that src block shows that 'firstline=23' is treated as
a switch by babel. So if there is any language that tries to use that
as a switch (or has a regexp that matches it), there could be trouble.
But in C it looks innocuous.
> If I'm trying to implement a firstline feature -- source blocks with
> new line numbering (-n) beginning at a given line number -- I'd prefer
> to use :firstline, but I didn't find anything to suggest `:XXX ZZ'
> header arguments to source blocks are available to the exporters.
>
HTH,
Chuck
