Re: org-remember templates with dynamic target headline

[Nick Dokos <nicholas.dokos@hp.com>]

Daniel J. Sinder <djsinder@gmail.com> wrote:

> I want a remember template that will have a target headline based on
> the date on which I call org-remember.
> 
> For a simple example, the effect I'd like to achieve is shown by
> putting the following in my .emacs:
> 
> (setq org-remember-templates
>       `(("Journal" ?j "* %u %?\n" "~/org/wjournal.org"
> ,(format-time-string "%G: Week %V"))))
> 
> I'm an elisp noob, but I realize the problem here is that
> format-time-string is only evaluated once when my .emacs is read.  So,
> unless I restart emacs every week.  This doesn't work.
> 
> How can I cause format-time-string to be re-evaluated whenever
> org-remember is called?
> 

You cannot, unless you change the code. Keith Swartz had a similar
question recently and although I cannot find it in the Gmane archive
(second time today - maybe I'm doing something wrong), here is the last
part of the thread:

,----
| To: Robert Goldman <rpgoldman@sift.info>
| cc: emacs-orgmode@gnu.org
| From: Nick Dokos <nicholas.dokos@hp.com>
| Cc: nicholas.dokos@hp.com
| Reply-to: nicholas.dokos@hp.com
| Subject: Re: [Orgmode] Re: Emacs-orgmode Digest, Vol 39, Issue 122 
| X-Mailer: MH-E 8.1; nmh 1.2; GNU Emacs 23.0.93
| Date: Sat, 30 May 2009 15:39:40 -0400
| Sender: nick@gamaville.dokosmarshall.org
| 
| Robert Goldman <rpgoldman@sift.info> wrote:
| 
| > > Date: Fri, 29 May 2009 23:24:58 -0700
| > > From: Keith Swartz <gnu@oneroad.com>
| > > Subject: [Orgmode] Lazy evaluation when defining org-remember-template
| > > To: "[orgmode]" <emacs-orgmode@gnu.org>
| > > Message-ID: <4A20D13A.2000603@oneroad.com>
| > > Content-Type: text/plain; charset=ISO-8859-1; format=flowed
| > > 
| > > ...
| > > 
| > > Is there a way I can make that command evaluate at the time it is 
| > > invoked, rather than when it is defined? I vaguely recall doing 
| > > something like this, but that was five job roles, three houses, two 
| > > recessions, and two kids ago. :)
| > > 
| > 
| > I can't swear that this will work, but note that the way you have
| > written this, it will all be evaluated at load time, as you say.  the
| > 'list' function will evaluate its arguments to build the list.
| > 
| > Now, if you don't want this to be evaluated when org-remember-templates
| > is set, you can quote the form:
| > 
| > '(format-time-string "%A")
| > 
| > [note that you quoted the argument to format-time-string.  I don't
| > believe that's necessary, since strings evaluate to themselves, but I
| > have not tested this.]
| > 
| > Actually, I think you would get something easier to read if you quoted
| > the whole list, instead of quoting each element.  Something like:
| > 
| > (list '("Todo" ?t "* TODO %?%^{To do} %^g\n  :LOGBOOK:\n  -
| > Added: %U\n  :END:" "d:/tmp/_my.todo" (format-time-string "%A"))))
| > 
| 
| That's correct.
| 
| > The question then is, "what happens when org-remember-templates is
| > retrieved?"  What you want is for this function to be evaluated when the
| > templates are found and used.  That will be done by
| > org-remember-apply-template, which we can examine....
| > 
| > Unfortunately, I don't see in there anything which retrieves (nth 4
| > entry), which is the place where your format-time-string goes, so I'm
| > not sure what is handling this.  It's a little confusing reading that
| > function's code, since "headline" is ambiguous between whether it means
| > the headline of the remember note to be inserted or the headline under
| > which to insert the note...  I believe it's the former.
| > 
| 
| It's the latter.
| 
| You can figure out things like this fairly quickly by inserting a
| (debug) at the appropriate place, and re-evaluating the defun. When the
| function gets called, it will jump into the debugger when it evals the
| (debug) form, and you can use the full power of lisp to examine
| state. For example, here I defined the template the way you suggested,
| placed a (debug) in org-remember-apply-template, just after the
| insertion of the template in the remember buffer, re-evaluated the defun
| (there is an eval-defun, but I prefer to do that by going to the end of
| the defun - which I can do quickly: repeat M-C-u until I'm at the
| beginning of the defun and M-C-f to move over the whole defun - and then
| C-x C-e to eval the last sexpression.)
| 
| I then call org-remember and in the resulting debug buffer, say
| 
|   e headline<RET>
| 
| which says 
| 
| (format-time-string "%A")
| 
|   e entry<RET>
| 
| which says
| 
| ("* TODO %?%^{To do} %^g
|   :LOGBOOK:
|   - 
| Added: %U
|   :END:" (quote "d:/tmp/_my.todo") (format-time-string "%A"))
| 
| Now you can see that the headline is the third element of this list
| (i.e. (nth 2 entry) - the numbering starts from 0).
| 
| > Perhaps someone else can figure this out, or perhaps you could just try
| > quoting the list and seeing if it works to evaluate the
| > format-time-string when you want it to.  Org usually does The Right Thing.
| > 
| But even org cannot perform miracles !-) Somebody has to "force the thunk"
| in order for delayed evaluation to work. You'd need something like this 
| patch:
| 
| --- a/lisp/org-remember.el
| +++ b/lisp/org-remember.el
| @@ -388,7 +388,7 @@ to be run from that hook to function properly."
|  				(functionp (nth 1 entry))))
|  		       (nth 1 entry)
|  		     org-default-notes-file))
| -	     (headline (nth 2 entry))
| +	     (headline (eval (nth 2 entry)))
|  	     (v-c (and (> (length kill-ring) 0) (current-kill 0)))
|  	     (v-x (or (org-get-x-clipboard 'PRIMARY)
|  		      (org-get-x-clipboard 'CLIPBOARD)
| 
| This should work in simple cases (in particular, because the headline is
| a string and strings evaluate to themselves, so it should not adversely affect
| any existing template), but I certainly have not thought about repercussions
| (including the possibility of *very* obscure bugs because somebody mistyped
| something in the template - that would be a maintenance nightmare that Carsten
| might not be willing to take on).
| 
| Thanks,
| Nick
`----

HTH,
Nick