Re: [O] org-e-latex: ignoreheading is not working any more.

[Nicolas Goaziou]

Hello,

Myles English <address@hidden> writes:

> Hi Yagnesh,
>
> Yagnesh Raghava Yakkala writes:
>> I have been using example setting suggested by Nicolas
>> (http://article.gmane.org/gmane.emacs.orgmode/55972) to tell exporter to skip
>> particular headline (with ignoreheading tag).
>>
>> It seems recent commit made this setup obsolete. could anybody suggest me the
>> alternative setting for this.?

There are only two changes:

#+BEGIN_SRC emacs-lisp
(add-to-list 'org-e-latex-translate-table '(headline . my-e-latex-headline))
#+END_SRC

is obsolete since `org-e-latex-translate-table' variable has been
removed. If you want to install a new translator, you have to create
a derived back-end, which is easy (see the example at the end of that
link).

Also, the hook will now be called with an argument: the back-end used as
a symbol.

Otherwise, the thread is still valid.

> I've been using this, (I notice it is significantly longer than the
> example in the link above so it may be overkill):
>
> #+BEGIN_SRC emacs-lisp
> (defun my-export-delete-headlines-tagged-noheading(heading-text)
>     "Goto headline `heading-text'"
>     (let ((wasfound t))
>       (while wasfound
>         (progn (org-element-map
>                 (org-element-parse-buffer 'headline)
>                 'headline
>                 (lambda (x)
>                   (if (member "noheading" (org-element-property :tags x))
>                       (progn
>                         (goto-char (org-element-property :begin x))
>                         (delete-region (point)
>                                        (progn
>                                          (forward-line 1)
>                                          (point)))
>                         (goto-char (point-min)))
>                     (setq wasfound nil)))
>                 nil
>                 t)) ;; stop at first find,
>         nil)        ;; start again from the top of the buffer
>       (goto-char (point-min))))
>   
>   (add-to-list 'org-export-before-processing-hook
>                'my-export-delete-headlines-tagged-noheading)
> #+END_SRC

Each time you delete an headline, you parse the full buffer again, so,
yes, it will be slow. You can simply reverse list returned by
`org-element-map' (but don't stop at first find) and walk that list,
deleting matching headlines along the way.

#+begin_src emacs-lisp
(defun my-export-delete-headlines-tagged-noheading (backend)
  (dolist (hl (nreverse (org-element-map (org-element-parse-buffer 'headline)
                                         'headline
                                         'identity)))
    (when (member "noheading" (org-element-property :tags hl))
      (goto-char (org-element-property :begin hl))
      (delete-region (point) (progn (forward-line) (point))))))
#+end_src

Another option is to use `org-map-entries', which doesn't require to
reverse the results (and doesn't use Org Element). This is left as an
exercise.


Regards,

-- 
Nicolas Goaziou