From mboxrd@z Thu Jan  1 00:00:00 1970
From: Seong-Kook Shin <cinsky@gmail.com>
Subject: accessing ATTR_HTML and CAPTION from custom
Date: Fri, 9 Mar 2018 19:53:49 -0800
Message-ID: <5095d0b6-787e-1ac0-fd71-2c1e73454d22@gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Return-path: <emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([2001:4830:134:3::10]:56247)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <cinsky@gmail.com>) id 1euVZz-0006kr-Lu
	for emacs-orgmode@gnu.org; Fri, 09 Mar 2018 22:53:56 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <cinsky@gmail.com>) id 1euVZy-0006KV-R8
	for emacs-orgmode@gnu.org; Fri, 09 Mar 2018 22:53:55 -0500
Received: from mail-io0-x233.google.com ([2607:f8b0:4001:c06::233]:40663)
	by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16)
	(Exim 4.71) (envelope-from <cinsky@gmail.com>) id 1euVZy-0006K3-LP
	for emacs-orgmode@gnu.org; Fri, 09 Mar 2018 22:53:54 -0500
Received: by mail-io0-x233.google.com with SMTP id v6so5702407iog.7
	for <emacs-orgmode@gnu.org>; Fri, 09 Mar 2018 19:53:52 -0800 (PST)
Received: from ?IPv6:2602:306:32b2:d7f0:9085:36a:b6b2:260a?
	([2602:306:32b2:d7f0:9085:36a:b6b2:260a])
	by smtp.gmail.com with ESMTPSA id
	i31sm1799972iod.78.2018.03.09.19.53.50 for <emacs-orgmode@gnu.org>
	(version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
	Fri, 09 Mar 2018 19:53:51 -0800 (PST)
Content-Language: en-US
List-Id: "General discussions about Org-mode." <emacs-orgmode.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/emacs-orgmode>,
	<mailto:emacs-orgmode-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/emacs-orgmode/>
List-Post: <mailto:emacs-orgmode@gnu.org>
List-Help: <mailto:emacs-orgmode-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/emacs-orgmode>,
	<mailto:emacs-orgmode-request@gnu.org?subject=subscribe>
Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org
Sender: "Emacs-orgmode"
	<emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org>
To: emacs-orgmode@gnu.org

Hello,

I'm using Nikola (https://getnikola.com/) with its orgmode plugin to 
write blog posts.  Their script contains following custom link for HTML 
export:

     (defun org-custom-link-img-url-export (path desc format)
       (cond
        ((eq format 'html)
         (format "<img src=\"%s\" alt=\"%s\"/>" path desc))))
     (org-add-link-type "img-url" nil 'org-custom-link-img-url-export)


And I have org-mode contents like this:

     #+CAPTION: some caption for the image
     #+ATTR_HTML: width="60%"
     [[img-url:/img/a.jpg]]

I found that somehow DESC parameter passed to above 
org-custom-link-img-url-export function contains all information 
regarding CAPTION and ATTR_HTML but unable to retrieve it properly.  Is 
there any org utility functions to retrieve them?  For example, I want 
to access 'width' parameter from ATTR_HTML like this:

     (defun org-custom-link-img-url-export (path desc format)
       (cond
        ((eq format 'html)
         (let ((width (SOME-FUNCTION desc :width)))
           (if (null width)
               (format "<img ... width=\"%s\"/>" ... width)
             (format "<img .../>" ...))))))

Could you help me how to do that?

Thank you.