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From: John Kitchin <jkitchin@andrew.cmu.edu>
Subject: Re: Document of org-map-entries
Date: Thu, 13 Oct 2016 10:05:35 -0400
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To: York Zhao <gtdplatform@gmail.com>
Cc: Nick Dokos <ndokos@gmail.com>, emacs-orgmode <emacs-orgmode@gnu.org>

Try this instead:

#+BEGIN_SRC emacs-lisp
(org-map-entries (lambda () (org-heading-components)) "myproperty<>\"\"")
#+END_SRC

Empty properties get returned as "" not nil I think.

York Zhao writes:

> One more question: how do I map only the entries that has a specific
> property
> defined? The following code didn't work.
>
> (org-map-entries
>      (lambda () (...))
>      "mytag+myproperty<>nil")
>
> Thanks,
>
>
> On Thu, Oct 13, 2016 at 1:00 AM, York Zhao <gtdplatform@gmail.com> wrote:
>
>> Thank you very much Nick.
>>
>> (info "(org) Using the mapping API") was the first doc I read which has
>> very little information on how to use the "match" parameter.  (info "(org)
>> Matching tags and properties") does have a lot more detail though.
>>
>>
>> On Thu, Oct 13, 2016 at 12:46 AM, Nick Dokos <ndokos@gmail.com> wrote:
>>
>>> York Zhao <gtdplatform@gmail.com> writes:
>>>
>>>
>>> > I wanted to know how to use the MATCH parameter in
>>> > `org-map-entries'. I've searched extensively, but was unable to find
>>> > much useful information. Can somebody please shed some lights on
>>> > this?
>>> >
>>>
>>> See
>>>
>>>    (info "(org) Using the mapping API")
>>>
>>> and
>>>
>>>    (info "(org) Matching tags and properties")
>>>
>>> --
>>> Nick
>>>
>>>
>>>
>>


-- 
Professor John Kitchin
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