Thank you very much for that suggestion.
Unfortunately, that does not seem to work for org-export-taskjuggler.
An exported taskjuggler file has extremely simple syntax. For a report, for
example, there is the header, "textreport id name {"
then a series of "attribute_name", "value" pairs such as "formats html".
Some attributes take multi-line string values, which are designated
"-8<- \n line1 \n line2 \n ->8-" (but with actual newlines rather than
"\n"s).
The taskjuggler export uses a very simple approach: when an org headline is
tagged as a report, it cycles through the properties, and for each
property, simply emits the property name followed by the property value (
org-taskjuggler-valid-report-attributes contains names such as "formats'
and "center"):

   (org-taskjuggler--indent-string
>     (org-taskjuggler--build-attributes
>      report org-taskjuggler-valid-report-attributes))
>
where

> (defun org-taskjuggler--build-attributes (item attributes)
>   (mapconcat
>    (lambda (attribute)
>      (let ((value (org-element-property
>                    (intern (upcase (format ":%s" attribute)))
>                    item)))
>        (and value (format "%s %s\n" attribute value))))
>    (remq nil attributes) ""))
>


For an org source such as

** Reports
> :PROPERTIES:
> :REPORT_KIND: textreport
> :formats:  html
> :center: -8<-
> :center+:    [#Plan Plan] | [#Resource_Allocation Resource Allocation]
> :center+:    ----
> :center+:    === Plan ===
> :center+:    <[report id="plan"]>
> :center+:    ----
> :center+:    === Resource Allocation ===
> :center+:    <[report id="resourceGraph"]>
> :center+: ->8-
> :END:
>

unfortunately, (org-element-property :center) returns only "-8<-", whereas
I want it to return a 9-line string.

-- Greg

--
Greg Sullivan   email: gregs@sulliwood.org   cell: 617-417-4746
70 Pigeon Hill Street, Rockport, MA 01966


On Mon, Feb 28, 2022 at 3:37 PM Kaushal Modi <kaushal.modi@gmail.com> wrote:

> On Sat, Oct 2, 2021 at 11:03 AM Hanno Perrey <hanno@hoowl.se> wrote:
> >
> > Hej,
> >
> > I have noticed that properties that stretch over multiple lines using
> > the :value+: syntax are ignored by org-element-property and therefore
> > also by e.g. org-export-get-node-property when exporting to ics via
> > ox-icalendar.el (see example below). I was wondering now whether this is
> > intentional and to be expected or a bug?
>
> I use the :value+: syntax for the subtree properties regularly. For
> exports, though, you need to prefix the properties with EXPORT_.
>
> See the (org) Export Settings node in Org manual.
>
> > When exporting sub-trees, special node properties can override the
> above keywords.  These properties have an ‘EXPORT_’ prefix.  For
> example, ‘DATE’ becomes, ‘EXPORT_DATE’ when used for a specific
> sub-tree.  Except for ‘SETUPFILE’, all other keywords listed above have
> an ‘EXPORT_’ equivalent.
>
> Here's one of the pathogenic test cases of ox-hugo:
>
> =====
> ** Custom front matter in multiple lines
> :PROPERTIES:
> :EXPORT_FILE_NAME: custom-front-matter-multiple-lines
> :EXPORT_DATE: 2017-07-24
> :EXPORT_HUGO_CUSTOM_FRONT_MATTER: :foo bar
> :EXPORT_HUGO_CUSTOM_FRONT_MATTER+: :baz zoo
> :EXPORT_HUGO_CUSTOM_FRONT_MATTER+: :alpha 1
> :EXPORT_HUGO_CUSTOM_FRONT_MATTER+: :beta "two words"
> :EXPORT_HUGO_CUSTOM_FRONT_MATTER+: :gamma 10
> :EXPORT_HUGO_CUSTOM_FRONT_MATTER+: :empty_string ""
> :END:
> =====
>
> All the HUGO_CUSTOM_FRONT_MATTER properties get collected as expected.
>
> Here's another example:
>
> =====
> #+author:
> #+options: toc:nil
> * Heading
> :PROPERTIES:
> :EXPORT_AUTHOR: abc def
> :EXPORT_AUTHOR+: ghi jkl
> :EXPORT_AUTHOR+: kmo pqr
> :END:
> =====
>
> C-c C-e C-s t A exports to:
>
> =====
>                        _________________________
>
>                                 HEADING
>
>                         abc def ghi jkl kmo pqr
>                        _________________________
>
>
> =====
>
>