When generating an HTML file from an org-mode document, I'd like to do a
GET operation to retrieve a property value from the drawer of an arbitrary
heading, using the CUSTOM_ID property to identify the heading.  From
Google-searching, I suspect that "org-heading-components" will be involved,
but I'm not proficient enough in elisp to be able to figure out how to use
it from the on-line examples I've found --- and I'm not proficient enough
in Emacs to use any built-in documentation about it ("apropos" doesn't
produce any results).

Here's an example, where GET-PROP is a macro I'd like to use:

==BEGIN==

#+MACRO: get-prop [????]

#+MACRO: get-title [omitted -- thanks to Nicolas Goaziou for the get-title
macro, at
https://lists.gnu.org/archive/html/emacs-orgmode/2014-02/msg00386.html]

* CLAUSES

** Affiliate status from voting control
  :PROPERTIES:
  :CUSTOM_ID: AffilDefn
  :CD-ID: AFFIL-VOTE
  :IMPORTANCE: Situational
  :PUSHBACK: Unlikely
  :END:

(a) One individual or organization ("Person") is an {{{DEFN(Affiliate)}}}
of another Person if,  directly or indirectly via one or more
intermediaries, one of those Persons /controls/ (as defined in subdivision
(b) below), or is controlled by, or is under common control with, the other
Person.

(b) [other text omitted]


* CONTRACT TEMPLATES

** Nondisclosure Agreement

{{{GET-PROP(AffilDefn,CD-ID)}}}: {{{GET-TITLE(AffilDefn)}}} -- pushback
from the other side is {{{GET-PROP(AffilDefn,PUSHBACK)}}}.

# This should export to:
# AFFIL-VOTE: Affiliate status from voting control -- pushback from the
other side is: Unlikely.

==END==

Thanks in advance,

--D. C.

*D*ell *C*harles "D. C." Toedt III  *(my** last name is pronounced "Tate") *
Attorney and neutral arbitrator -- tech contracts and intellectual property
Lecturer, University of Houston Law Center
​Editor, ​​​Common Draft <http://www.commondraft.org/> project:  A readable
library of best-practices contract clauses,
     with extensive citations and commentary, updated often.
dc@toedt.com     LinkedIn: dctoedt <http://www.linkedin.com/in/dctoedt>
Calendar
<https://www.google.com/calendar/embed?src=dc.toedt@toedt.com&mode=WEEK>
(redacted)
O: +1 (713) 364-6545    C: +1 (713) 516-8968
​​

​
Houston, Texas (Central time zone)

Unless expressly stated otherwise, this message is not intended
to serve as an electronic signature nor as assent to an agreement.