Allow remapping front-matter variables

[kaibagley]

Hey, thanks for the great package

I have an org-roam setup i've added around 500 files to over the last couple years, and in all of these I use

...
#+CREATED: <date>
#+MODIFIED: <date>
...

As the creation and modified dates. But ox-hugo requires:

...
#+date: <date>
#+hugo_lastmod: <date>
...

I'd prefer not to replace-regexp for all files if possible, so I was wondering how you would feel about allowing users to remap front matter property names, maybe with an alist (('hugo_lastmod . "CREATED") ('date . "MODIFIED")) or something along those lines.

Thanks a lot!

[dnaeon]

Similar story here, interested to know if we can map hugo properties to already existing org-mode properties, thanks!

[dnaeon]

Currently I'm using the CREATED property to all my org-roam nodes, which is added via the following hook.

(defun dnaeon/org-set-created-property ()
  "Sets the CREATED property when a new org-roam node is created"
  (org-set-property "CREATED" (format-time-string "%Y-%m-%d %T")))

;; Add CREATED property to each org-roam node
(add-hook 'org-roam-capture-new-node-hook #'dnaeon/org-set-created-property)

When exporting via ox-hugo I'm currently using this workaround, until a proper solution exists.

;; All my org-roam notes contain the `CREATED' property, which specifies the
;; creation date of the note. This wrapper adds the `:date' property to the
;; export environment, which `ox-hugo' will use when exporting to Markdown.
(defun org-export-get-environment/add-date (orig-fun &rest args)
  (let ((env (apply orig-fun args))
        (created (org-entry-get nil "CREATED")))
    (plist-put env :date created)))

(advice-add 'org-export-get-environment :around #'org-export-get-environment/add-date)

The advice function will push the :date property to the export environment used by ox-hugo, so the front-matter will contain the date property. Other properties we can play with here are :hugo-publishdate, :hugo-lastmod, etc.

Ideally, the org-export-get-environment/add-date hook will be used only when the backend is 'hugo, since that's what ox-hugo uses internally.