finding a parent node

finding a parent node

[Łukasz Stelmach]

Hello All.

What is the best way to iterate over ((great)*grand)?parent headlines of
the current one (at point), that meets some criteria.

--8<---------------cut here---------------start------------->8---
* Projects
  I am working on.

** Project for Mondays

*** tasks

*** resources

** Project for the rest of the week

*** tasks                        :TASKS:
^                      <------ (3) I'd like it to move here
    If I do this stuff I will rule the world.
                             ^       <----- (2) or it may be here.
**** TODO do this                  

**** TODO do that                  
     I am trying.
                 ^     <------ (1) point is here
**** TODO WAT?

*** resources
--8<---------------cut here---------------end--------------->8---

With my point somewher deep I'like to find the closest parent heading
tagged :TASKS:.

If that helps, I'd like to export the subtree of the heading I find by
simply running the export function at any point of the subtree.

Kind regards,
-- 
Łukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics

Re: finding a parent node

[Thorsten Jolitz]

l.stelmach@samsung.com (Łukasz Stelmach) writes:

Hello,

> What is the best way to iterate over ((great)*grand)?parent headlines of
> the current one (at point), that meets some criteria.

not an answer to your question, but rather a related question I wanted
to post anyway, so I do it in this thread:

simple-test.org:
#+begin_src org
* header 1
  :PROPERTIES:
  :CUSTOM_ID: XYZ22
  :END:
* header 2
  [2013-06-28 Fr 11:01]
** subheader 1
Some text
** subheader 2

More text and a table

| label  | col1 | col2 |
|--------+------+------|
| string | 3    | 4    |

Text and a src-block

#+begin_src emacs-lisp
 (+ 3 4)
#+end_src

#+end_src

parse buffer:
#+begin_src emacs-lisp
(progn
  (goto-char (point-max))
  (newline 2)
  (insert
   (format "%s"
           (with-current-buffer
               (find-file-noselect
                "/path/to/simple-test.org")
             (setq tree (org-element-parse-buffer))))) )
#+end_src

excerpts form parse-tree:
#+begin_src emacs-lisp
  (org-data
   nil
   ;; first headline
   (headline
    (:raw-value header 1 :begin 1 :end55 :pre-blank0 :hiddenp
  outline :contents-begin 12 :contents-end 55 :level 1 :priority
  nil :tags nil :todo-keyword nil :todo-type nil :post-blank
  1 :footnote-section-p nil :archivedp nil :commentedp nil :quotedp
  nil :CUSTOM_ID XYZ22 :CATEGORY simple-test :title (header
  1) :parent #0)

    (section (:begin 12 :end 55 :contents-begin 12 :contents-end
  55 :post-blank 0 :parent #1)

     (property-drawer (:begin 12 :end 55 :hiddenp
  outline :contents-begin 27 :contents-end 47 :post-blank
  0 :post-affiliated 12 :parent #2) (node-property (:key
  CUSTOM_ID :value XYZ22 :begin 27 :end 47 :post-blank 0 :parent
  #3)))))

   ;; second headline
   (headline (:raw-value header 2 :begin 55 :end 295 :pre-blank
  0 :hiddenp outline :contents-begin 66 :contents-end 295 :level
  1 :priority nil :tags nil :todo-keyword nil :todo-type
  nil :post-blank 0 :footnote-section-p nil :archivedp
  nil :commentedp nil :quotedp nil :CATEGORY
  simple-test :title (header 2) :parent #0)

    (section (:begin 66 :end 90 :contents-begin 66 :contents-end
  90 :post-blank 0 :parent #1) (paragraph (:begin 66 :end
  90 :contents-begin 66 :contents-end 90 :post-blank
  0 :post-affiliated 66 :parent #2)

     (timestamp (:type inactive :raw-value [2013-06-28 Fr
  11:01] :year-start 2013 :month-start 6 :day-start 28 :hour-start
  11 :minute-start 1 :year-end 2013 :month-end 6 :day-end
  28 :hour-end 11 :minute-end 1 :begin 68 :end 89 :post-blank
  0 :parent #3)) )) ...) )

#+end_src

now I can use `org-element-map' to access the elements and their attributes:

#+begin_src emacs-lisp
(insert
 (format "\n\n%s"
         (org-element-map
             tree
             'timestamp
           '(lambda (X) (org-element-property :raw-value X)))))

;; => ([2013-06-28 Fr 11:01])

#+end_src

this gives me the first timestamp element and its property list:
#+begin_src emacs-lisp
(setq stamp1
      (org-element-map
          tree
          'timestamp
        'identity nil t))
#+end_src

but for further processing I always struggle with the :parent attribute and
the circularities in the list. 

I often would like to use just a sublist like this, with :parent being a Link
or ID and not the parent object that refers to its parent object and so on ...

#+begin_src emacs-lisp
(timestamp (:type inactive :raw-value [2013-06-28 Fr
  11:01] :year-start 2013 :month-start 6 :day-start 28 :hour-start
  11 :minute-start 1 :year-end 2013 :month-end 6 :day-end
  28 :hour-end 11 :minute-end 1 :begin 68 :end 89 :post-blank
  0 :parent <<ID of or LINK to #3>>))
#+end_src

I tried to use the NO-RECURSION arg of `org-element-map' for this, but often
the parent is a headline or section, and then 'org-element-map' doesn't enter
headlines or sections and returns nil, i.e. the timestamp is never found. 

Is there a way - using the parser/export framework toolbox - to avoid these
circularities, i.e. to either ignore the :parent attribute or better replace
the list object in it by something else that nevertheless identifies the
parent unmistakenly? 

I know that with special bookkeeping while walking the tree one can deal with
these circularities, maybe I'm just new to this stuff, but I feel they make
the usual processing of such a nested list a bit complicated. 

--
cheers,
Thorsten

Re: finding a parent node

[Thorsten Jolitz]

l.stelmach@samsung.com (Łukasz Stelmach) writes:

Hello Lukasz, 

assume my simple-test.org with a :TASK: tag:

#+begin_src org
* header 1
  :PROPERTIES:
  :CUSTOM_ID: XYZ22
  :END:
* header 2                             :TASK:
  [2013-06-28 Fr 11:01]
** subheader 1
Some text
** subheader 2

More text and a table

| label  | col1 | col2 |
|--------+------+------|
| string | 3    | 4    |

Text and a src-block

#+begin_src emacs-lisp 
 (+ 3 4)
#+end_src

#+end_src

> With my point somewher deep I'like to find the closest parent heading
> tagged :TASKS:.

Lets move point to the source-block and get `org-element-context':

#+begin_src emacs-lisp
(with-current-buffer
    (find-file
     "/path/to/simple-test.org")
    (goto-char (point-min))
    (org-babel-next-src-block)
    (message "%s" (point))
     (format "%s"
     (org-element-context)))
#+end_src

#+begin_quote
"(src-block (:language emacs-lisp :switches nil :parameters nil :begin 319
 :end 362 :number-lines nil :preserve-indent nil :retain-labels t :use-labels
 t :label-fmt nil :hiddenp nil :value (+ 3 4) :post-blank 0 :post-affiliated
 319 :parent nil))"
#+end_quote

too bad, does not work in isolated use, :parent is nil. Othewise one could
get the parent(s) and check for the :TASK: tag. 

So the only way to find this headline I know of would be:

#+begin_src emacs-lisp
(with-current-buffer
  (find-file-noselect
     "/path/to/simple-test.org")
  (let ((tree (org-element-parse-buffer)))
  (org-element-map tree 'headline
   (lambda (hl)
     (and
      (member "TASK" (org-element-property :tags hl))
      (list (org-element-property :begin hl)
            (org-element-property :end hl)))))))
#+end_src

returns

,-----------
| ((55 362))
`-----------

so you could at least find out if (point) is inside a headline with a :TASK:
tag, then get this headline and use its attribute list to move to some place
inside of it. 

But I'm sure Nicolas can give you a much better solution (I would be
interested in that solution too). 

-- 
cheers,
Thorsten

Re: finding a parent node

[Łukasz Stelmach]

It was <2013-07-02 wto 13:06>, when Thorsten Jolitz wrote:
> l.stelmach@samsung.com (Łukasz Stelmach) writes:
>
> Hello Lukasz, 
>
> assume my simple-test.org with a :TASK: tag:
>
> #+begin_src org
> * header 1
>   :PROPERTIES:
>   :CUSTOM_ID: XYZ22
>   :END:
> * header 2                             :TASK:
>   [2013-06-28 Fr 11:01]
> ** subheader 1
> Some text
> ** subheader 2
>
> More text and a table
>
> | label  | col1 | col2 |
> |--------+------+------|
> | string | 3    | 4    |
>
> Text and a src-block
>
> #+begin_src emacs-lisp 
>  (+ 3 4)
> #+end_src
>
> #+end_src
>
>> With my point somewher deep I'like to find the closest parent heading
>> tagged :TASKS:.
>
> Lets move point to the source-block and get `org-element-context':
>
> #+begin_src emacs-lisp
> (with-current-buffer
>     (find-file
>      "/path/to/simple-test.org")
>     (goto-char (point-min))
>     (org-babel-next-src-block)
>     (message "%s" (point))
>      (format "%s"
>      (org-element-context)))
> #+end_src
> #+begin_quote
> "(src-block (:language emacs-lisp :switches nil :parameters nil :begin 319
>  :end 362 :number-lines nil :preserve-indent nil :retain-labels t :use-labels
>  t :label-fmt nil :hiddenp nil :value (+ 3 4) :post-blank 0 :post-affiliated
>  319 :parent nil))"
> #+end_quote
>
> too bad, does not work in isolated use, :parent is nil. Othewise one could
> get the parent(s) and check for the :TASK: tag. 
>
> So the only way to find this headline I know of would be:
>
> #+begin_src emacs-lisp
> (with-current-buffer
>   (find-file-noselect
>      "/path/to/simple-test.org")
>   (let ((tree (org-element-parse-buffer)))
>   (org-element-map tree 'headline
>    (lambda (hl)
>      (and
>       (member "TASK" (org-element-property :tags hl))
>       (list (org-element-property :begin hl)
>             (org-element-property :end hl)))))))
> #+end_src
>
> returns
>
> ,-----------
> | ((55 362))
> `-----------
>
> so you could at least find out if (point) is inside a headline with a :TASK:
> tag, then get this headline and use its attribute list to move to some place
> inside of it. 
>
> But I'm sure Nicolas can give you a much better solution (I would be
> interested in that solution too). 

This might be enough for me as I get the tree in the exporting
code.  However, this way is far from efficient. If only there was a way
to find the current element in the tree.

I am not sure yet, but a sequence of org-back-to-heading  and
re-search-backward inside a save-excursion may be the easiest way to
place the point where I want it.

Any other thoughts?
-- 
Łukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics

Re: finding a parent node

[Thorsten Jolitz]

l.stelmach@samsung.com (Łukasz Stelmach) writes:

> It was <2013-07-02 wto 13:06>, when Thorsten Jolitz wrote:
>> l.stelmach@samsung.com (Łukasz Stelmach) writes:
> This might be enough for me as I get the tree in the exporting
> code.  However, this way is far from efficient. If only there was a way
> to find the current element in the tree.
>
> I am not sure yet, but a sequence of org-back-to-heading  and
> re-search-backward inside a save-excursion may be the easiest way to
> place the point where I want it.
>
> Any other thoughts?


#+begin_src emacs-lisp
(defun tj/export-enclosing-header (tag backend)
  "Export enclosing header with TAG member of tags."
  (save-excursion
    (unless (org-on-heading-p)
      (outline-previous-heading))
    (while (not (member tag (org-get-tags)))
      (outline-up-heading 1))
    (org-export-as backend 'SUBTREEP)))
#+end_src


then doing (with point e.g. at the src-block)

,------------------------------------------
| M-: (tj/export-enclosing-header "TASK" 'html)
`------------------------------------------

works in my sample org file. Not sure if this what you are looking for

-- 
cheers,
Thorsten