Re: [O] creating new #+KEYWORD: variables

[John Kitchin]

I have used something like this:

(defun gb-set-filetag (tag value)
	"Set filetag TAG to VALUE.
	If VALUE is nil, remove the filetag."
	(save-excursion
	(goto-char (point-min))
	(if (re-search-forward (format "#\\+%s:" tag) (point-max) 'end)
	;; replace existing filetag
	(progn
	(beginning-of-line)
	(kill-line)
	(when value
	(insert (format "#+%s: %s" tag value))))
	;; add new filetag
	(if (looking-at "^$") ;empty line
	;; at beginning of line
	(when value
	(insert (format "#+%s: %s" tag value)))
	;; at end of some line, so add a new line
	(when value
	(insert (format "\n#+%s: %s" tag value)))))))

I am not sure what you mean by the end of the headers. This code ends up putting new keywords at the end of the file. You could add some code I guess that jumps back to the top, and puts it at the next line after the last #+ or something.

John

-----------------------------------
Professor John Kitchin 
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803

@johnkitchin
http://kitchingroup.cheme.cmu.edu

On Thu, Nov 15, 2018 at 7:14 AM Matt Price <address@hidden> wrote:

On Sat, Nov 10, 2018 at 1:58 PM Nicolas Goaziou <address@hidden> wrote:

Hello,

John Kitchin <address@hidden> writes:

> You can retrieve keywords in the org-file like this:
>
> (defun get-keyword (key)
>   (org-element-map (org-element-parse-buffer) 'keyword
>     (lambda (k)
>       (when (string= key (org-element-property :key k))
> (org-element-property :value k)))
>     nil t))

As a minor addendum,

    (org-element-parse-buffer 'element)

is more efficient in this case.

An even more efficient way to retrieve keywords, assuming buffer is not
already parsed, would be:

    (org-with-point-at 1
      (let ((case-fold-search t)
            (regexp (format "^[ \t]*#\\+%s:" key))
            (result nil))
        (while (re-search-forward regexp nil t)
          (let ((element (org-element-at-point)))
            (when (eq 'keyword (org-element-type element))
              (push (org-element-property :value element) result))))
        result))

This is very helpful, Nicolas and John. 

What about *setting* a global keyword? I would like to write something like this:

(defun org-lms-set-global-prop-value (key value)
  "Add or update keyword KEY in the org file header."
  (save-excursion
    (goto-char (point-min))
    (insert (format "#+%s: %" (upcase key) value))))

But

(a) insert the value at the *end* of the headers section, not the beginning.

(b) preferably replace any existing values of the keyword rather than write a whole new line.

(b) I guess could be achieved with something like

(replace-regexp (format "\(^[ \t]*#\\+%s: \)\(.*\)" key) (concat "\1" value))

But what about (a)? I thought org already had a couple of functions that performed this kind of serach but now I'm not so sure. 

 

Regards,

--
Nicolas Goaziou