Re: Extending the Org syntax by a custom exporter - how to do it?

[John Kitchin <jkitchin@andrew.cmu.edu>]

I played around with this a little. Here is a minimal kind of example
with a custom exporter that handles quiz blocks separately. The quiz
block can have some attributes defined that get used in rendering the
HTML. Is this along the lines of what you are trying to do? 

* A custom type

#+BEGIN_EXAMPLE
Example text in a block to make sure it gets handled
#+END_EXAMPLE

Some instructions for the quiz.

#+ATTR_quiz: :points 5 :correct-answer A
#+BEGIN_quiz
test quiz
- [ ] answer A
- [ ] answer B
#+END_quiz


#+BEGIN_SRC emacs-lisp :exports none
(defun my-org-html-export-block (export-block contents info)
  "Transcode a EXPORT-BLOCK element from Org to HTML.
CONTENTS is nil.  INFO is a plist used as a communication
channel. QUIZ blocks are handled separately."

  (cond
   ;; handle our special quiz block
   ((string= (org-element-property :type export-block) "QUIZ")

    (format
     "<b>got it:</b> %s points, correct answer = %s 
<br>
You would have to parse the body to generate your html here.
<br>
<pre>%s</pre>"
     (plist-get 
      (read (format "%s" (org-element-property :attr_quiz export-block)))
     :points)
     (plist-get 
      (read (format "%s" (org-element-property :attr_quiz export-block)))
     :correct-answer)
     (org-element-property :value export-block)
     ))
   ;; handle every other kind of block
   (t
    (org-html-export-block (export-block contents info)))))

(org-export-define-derived-backend 'my-html 'html
  :translate-alist '((export-block . my-org-html-export-block))
  ;; quiz blocks will not be parsed, they are handled directly in org-html-export-block.
  :export-block "quiz"
)


(browse-url (org-export-to-file 'my-html "custom-element.html"))
#+END_SRC

#+RESULTS:
: #<process open custom-element.html>






John Kitchin <jkitchin@andrew.cmu.edu> writes:

> Could you remind us of what you are trying to do? It seems like you may
> not necessarily need custom elements (although that could be
> useful). For example, you can put a lot of information in properties of
> a headline.
>
> You might be interested in this:
>
> http://kitchingroup.cheme.cmu.edu/blog/2014/11/23/Machine-gradable-quizzes-in-emacs+org-modex/
>
> I recently used this is in my class of 58 students (who all used emacs
> and org-mode to take a quiz!).
>
>
> Marcin Borkowski <mbork@wmi.amu.edu.pl> writes:
>
>> Hello there,
>>
>> this is close to necromancy, but let me revive this old thread.
>>
>> On 2014-03-16, at 11:16, Nicolas Goaziou wrote:
>>
>>> Another, more advanced option, is to use a parse tree filter to create
>>> pseudo-types, i.e., element or object types that don't exist in regular
>>> Org syntax. See `math-block' type in "ox-latex.el", in particular
>>> `org-latex-math-block-tree-filter'.
>>
>> Now that I actually started work on my exporter, I'd like to investigate
>> this further.  The thing is, I'm not sure where to start.  First of all,
>> I have a bit old Org-mode (without latex-math-blocks); I guess I'll just
>> have to update it (I'll try to do an Elpa update in a minute).  But my
>> question is:
>>
>> 1. Is it a good idea to instrument `org-latex--wrap-latex-math-block'
>> for Edebug to learn what's happening?
>>
>> 2. Is there any other (possibly simpler) instance of pseudo-blocks I
>> could study?  It seems to me (from the docstring) that latex-math-blocks
>> are a bit tricky; what I'm interested in is more like creating a new
>> element similar to e.g. italics.
>>
>> (Reagrdless of the answer, I'll try with Edebug, but I'm a bit afraid
>> that I won't understand what's going on).
>>
>> Also, if (when?) I "get it", I'm going to describe the process of adding
>> a pseudo-object somewhere (I consider my blog, or maybe I could upload
>> it to Worg?), so that other people can learn it easier.  But for now, I
>> might need help.
>>
>> Best,

-- 
-----------------------------------
John Kitchin
Professor
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
http://kitchingroup.cheme.cmu.edu