CLOSED: [2016-12-23 Fri 18:01] SCHEDULED: <2016-12-23 Fri>
:PROPERTIES:
:CREATED: [2016-12-22 Thu 20:16]
:ID: 2016-12-23-my-org-region-to-property
:END:
:LOGBOOK:
- State "DONE"       from "DONE"       [2019-11-15 Fri 14:55]
- State "DONE"       from "NEXT"       [2016-12-23 Fri 18:01]
:END:

Silent update 2019-09-25: added to [[id:2019-09-25-using-orgmode][blog series "Using Org Mode Features"]]

Update 2019-11-15: Screencast demo

Please do read [[id:2019-09-25-using-orgmode][my "Using Org Mode Features" (UOMF) series page]] for
explanations on articles of this series.

If you are using [[id:tags-emacs][Org-mode]] you might find yourself in a position, where
you want to set or update a property value for an existing property.

In my case, I frequently do this for [[id:2015-02-01-muttfilter][my contacts]]. Whenever a phone
number changes, I add a note to the heading of the corresponding
contact. Additionally, I maintain phone numbers in properties as well.
To do this in a sane way, I only mark the new phone number (region)
and press a keyboard shortcut which calls an Elisp function. This
function asks me for the name of a property (with tab completion).
Then, the value of this property is set to the string of the region.

Very handy.

Here is the Elisp code of ~my-org-region-to-property()~ which was made
possible with the help of [[http://article.gmane.org/gmane.emacs.orgmode/106364][Antoine R. Dumont]]:

-------------------

#+BEGIN_SRC elisp
(defun org-read-entry-property-name ()
  "Read a property name from the current entry."
  (let ((completion-ignore-case t)
        (default-prop (or (and (org-at-property-p)
                               (org-match-string-no-properties 2))
                          org-last-set-property)))
    (org-completing-read
     (format "Property [%s]: " (if default-prop default-prop ""))
     (org-entry-properties nil nil)
     nil nil nil nil default-prop)))

(defun my-org-region-to-property (&optional property)
  "Copies the region as value to an Org-mode property"
  (interactive)
  ;; if no region is defined, do nothing
  (if (use-region-p)
      ;; if a region string is found, ask for a property and set property to
      ;; the string in the region
      (let ((val (replace-regexp-in-string
                  "\\`[ \t\n]*" ""
                  (replace-regexp-in-string "[ \t\n]*\\'" ""
                                            (substring (buffer-string)
                                                       (- (region-beginning) 1)
                                                       (region-end))))
                 )
            ;; if none was stated by user, read property from user
            (prop (or property
                      (org-read-entry-property-name))))
        ;; set property
        (org-set-property prop val))))
#+END_SRC

In [[https://asciinema.org/a/D55MFKElA0RVpu9A0c6kpcH1N][the following screencast]], you can see how I am adding a new contact
to my Org mode =contacts.org= and how I make use of
=my-org-region-to-property()=:

#+BEGIN_EXPORT html
<a href="https://asciinema.org/a/D55MFKElA0RVpu9A0c6kpcH1N" target="_blank"><img src="https://asciinema.org/a/D55MFKElA0RVpu9A0c6kpcH1N.svg" /></a>
#+END_EXPORT