thanks John,

On Fri, Jul 30, 2021 at 9:01 PM John Kitchin <jkitchin@andrew.cmu.edu>
wrote:

> I think the way to do this is to use a function in
> org-export-before-processing-hook to add it if you don't find it.
>
> you can still use org-ml to generate the string that gets inserted. I
> guess you would just go to the end of the buffer and insert it.
>
>
this is what I came up with. I don't know if it might be useful to others,
or if maybe a modified version might be worth putthing into some kind of
package.

(use-package org-cite
  :config
  (defcustom org-export-ensure-biblio
    t
    "Whether or not to create bibliography slide when missing from document"
    :group 'org-export
    :type 'string)

  (defcustom org-export-biblio-heading-id
    "bibliography"
    "custom id for bibliography slide heading in org-re-reveal"
    :group 'org-export
    :type 'string
    :package-version '(org-re-reveal . 1.5))

  (defcustom org-export-biblio-heading-text
    "Sources"
    "Default Title to display above bibliography in org-re-reveal"
    :group 'org-export
    :type 'string
    )

  (defun mwp-add-biblio-export-hook (&optional backend)
    "If there's a citation object, search for a bibliography keyword;
if that's missing, create a new headline with the keyword. Intended for use
with
org-export-before-parsing-hook"
    (save-excursion
      (when (and org-export-ensure-biblio
                 (not (re-search-forward "^[ ]?+#\\+print_bibliography:"
nil t))
                 (progn
                   (goto-char (point-min))
                   (re-search-forward org-element-citation-key-re
(point-max) t)))
        (let* ((title (or org-export-biblio-heading-text "Sources"))
               (id (or org-export-biblio-heading-id "bibliography")))
          (goto-char (point-max))
          (insert
           (org-ml-to-trimmed-string
            (org-ml-build-headline
             :title `(,title)
             (org-ml-build-section
              (org-ml-build-property-drawer
               (org-ml-build-node-property "CUSTOM_ID" id))
              (org-ml-build-keyword "print_bibliography" "")))))))))

  (add-hook org-export-before-parsing-hook 'mwp-add-biblio-export-hook))

Matt


> John
>
> -----------------------------------
> Professor John Kitchin (he/him/his)
> Doherty Hall A207F
> Department of Chemical Engineering
> Carnegie Mellon University
> Pittsburgh, PA 15213
> 412-268-7803
> @johnkitchin
> http://kitchingroup.cheme.cmu.edu
>
>
>
> On Fri, Jul 30, 2021 at 8:18 PM Matt Price <moptop99@gmail.com> wrote:
>
>> Goal:
>> conditionally add a headline with content to parse tree using either
>> org-export-before-parsing-hook or org-export-filter-parse-tree-functions
>>
>> Explanation:
>> I use org-re-reveal to make lecture slides from subtrees. Often I forget
>> to add a heading with #+print_bibliography: and as a result org-cite does
>> not generate the bibliography, and my citations are not wrapped in links.
>> I'd like to search *either* the parse tree  *or* the temporary export
>> buffer for the #+print_bibliography keyword, and if it's not found, add a
>> headline to the end of the subtree/parse-tree with the appropriate
>> information.
>>
>> I can easily generate the proper lisp object with the org-ml package:
>>
>> (org-ml-build-headline :title '("Sources")
>>                        (org-ml-build-section
>>                         (org-ml-build-property-drawer
>>                          (org-ml-build-node-property "CUSTOM_ID"
>> "bibliography"))
>>                         (org-ml-build-keyword "print_bibliography" "" )
>>                         ))
>>
>> And if I want I can turn that into a string by wrapping it in
>> (org-ml-to-trimmed-string ...)
>>
>> However, I'm not sure how best to add it to the exported data.  I believe
>> I can add a function to either org-export-before-parsing-hook or
>> org-export-filter-parse-tree-functions, but beyond that I'm a bit lost.
>> It's not immediately obvious how to find the last headline and append
>> another headline after that headline's section. Looking at the nesting
>> confuses me somewhat and I'm afraid I'll break the data structure.
>>
>> Has anyone done something like this before and do you have ideas?
>>
>> Thank you!
>>
>