How do I pick a date in my new major mode?

Question

I want to insert a date in the current buffer.

I know the function calendar-cursor-to-date that when invoked gives back the date at which the cursor is.

But how do I get that info back into my program?

Here is what I've got so far:

(defun insert-new-entry ()
   (interactive)
   (save-excursion
      (goto-char (point-max))
      ;;next comes mostly pseudocode except *calendar-cursor-to-date*

      (calendar)
       (let ((x (bind-key (kdb "enter) 'calendar-mode calendar-cursor-to-date)))
            (insert x))))

So in english it's:

1. go to the last location in the buffer
2. open calendar
3. store in x whatever is returned where enter is pressed
4. insert it into buffer.

The problem is step 3. How do I store into x whatever is returned from calendar-cursor-to-date?

Thanks

Answer 1

As stated in a comment of mine underneath a similar / duplicate question by this original poster -- how to detect selection in date mode? -- the function org-read-date is the best choice:

(insert (org-read-date))

The following example function demonstrates proposed usage of org-read-date based on the outline of the original poster:

(defun insert-date-at-eob ()
"Go to the end of the buffer, insert a date using the function `org-read-date',
and return to the original position in the buffer."
(interactive)
  (save-excursion
    (goto-char (point-max))
    (insert (org-read-date))))

For more information on the function org-read-date, type M-x describe-function RET org-read-date RET

Answer 2

It's not as clean as I'd like, but it works:

(defvar *calendar-entry-buffer* nil)

(defun select-date ()
  (interactive)
  (destructuring-bind (month day year) (calendar-cursor-to-date)
    (if *calendar-entry-buffer*
        (progn
          (save-current-buffer
            (set-buffer *calendar-entry-buffer*)
            (insert (format "%d-%02d-%02d\n" year month day)))
          (setf *calendar-entry-buffer* nil)
          (calendar-exit)))))


(define-key calendar-mode-map (kbd "RET") 'select-date)

(defun insert-date-at-point ()
  (interactive)
  (setf *calendar-entry-buffer* (current-buffer))
  (calendar))