Nick, Thanks very much! Excellent description. Cheers. Fil On 13 April 2012 00:35, Nick Dokos <nicholas.do...@hp.com> wrote:
> Filippo A. Salustri <salus...@ryerson.ca> wrote: > > > Hi all, > > I'm looking for a little coding help. > > > > I want to try to a task's priority automatically, based on the > priorities of its subtasks. > > Specifically, I'd like to set the priority of the task to the priority > of the highest-priority > > subtask. > > And I'd like that task priority to be updated (if necessary) > automatically any time I change the > > priority of one of its subtasks. > > > > The basic idea in all of these situations is to use org-map-entries > from the mapping API: > > (info "(org) Using the mapping API") > > to walk the entries, applying a function on each. > > The function to apply on each entry is frequently a specialization > of one of the functions provided by the property API: > > (info "(org) Using the property API") > > In this case, you need a function to get the priority of each entry: > > (def fas/task-priority () > (org-entry-get (point) "PRIORITY")) > > which you can then give to org-map-entries: > > (org-map-entries (function fas/task-priority) t 'tree) > > The assumption here is that we are at the head node and we have > an arbitrary number of subnodes. The call above will accumulate > the priorities of each subnode in a list (if a subnode does not > have a priority assigned, the priority will be nil). > > For example, applying > > * section > ** [#B] subsection > *** [#C] subsubsection > **** paragraph > ***** [#B] subparagraph > > will return the list > > (nil "B" "C" nil "B") > > It is then just a matter of finding the highest priority and applying > it to the top node. Assuming that "A" is higher priority than "B" etc, > something like this will do: > > --8<---------------cut here---------------start------------->8--- > (defun fas/task-priority () > (org-entry-get (point) "PRIORITY")) > > (defun fas/set-task-priority () > (interactive) > (let* ((priorities (org-map-entries (function fas/task-priority) t 'tree)) > (sortedpriorities (sort (delq nil priorities) (function > string-lessp)))) > (if sortedpriorities > (org-priority (aref (car sortedpriorities) 0))))) > --8<---------------cut here---------------end--------------->8--- > > org-priority wants a character, but sortedpriorities is a list of > strings, hence the aref rigmarole. It should work even if *no* > priorities are set at all: sortedpriorities will be nil, so nothing will > be done. > > Nick > > -- \V/_ Filippo A. Salustri, Ph.D., P.Eng. Mechanical and Industrial Engineering Ryerson University 350 Victoria St, Toronto, ON M5B 2K3, Canada Tel: 416/979-5000 ext 7749 Fax: 416/979-5265 Email: salus...@ryerson.ca http://deseng.ryerson.ca/~fil/
