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From: "Jan Böcker" <jan.boecker@jboecker.de>
To: sand@blarg.net
Cc: emacs-orgmode List <emacs-orgmode@gnu.org>,
	Carsten Dominik <carsten.dominik@gmail.com>
Subject: Re: Embedding images as data: URIs in the HTML exporter (was: MathJax is now the default for HTML math)
Date: Fri, 03 Sep 2010 17:53:01 +0200	[thread overview]
Message-ID: <4C8119DD.3030408@jboecker.de> (raw)
In-Reply-To: <19584.26243.447375.125613@priss.frightenedpiglet.com>

On 09/03/2010 05:07 AM, sand@blarg.net wrote:
> How about doing the same data: URI embedding for images in the HTML
> exporter?  It should be possible to implement it entirely inside
> Emacs.  It would have to be optional, of course.
> 
> Derek
> 

This is certainly possible, the following patch would do this to *every*
image. Maybe someone who knows the HTML exporter code better than I do
can make it configurable and submit a patch.

Bonus points for an extra option which only embeds images smaller than
32 KB to keep it compatible with Internet Explorer.

Maybe something like this configuration variable:


(defcustom org-export-html-embed-images-as-data-uris 'never
"Controls if references to inlined images (see
`org-export-html-inline-images') are replaced with their contents as a
data: URI.

Possible values:
'never (default)   All images are inlined using normal URL references.
'always            Embed all images as data: URIs.
'up-to-32KB        Use data: URIs only for images up to 32 KByte
                   (Internet Explorer does not allow bigger data: URIs)

See also: http://en.wikipedia.org/wiki/Data_URI_scheme"
:group org-export-html
:type (choice (const never) (const always) (const up-to-32KB)))



-- Jan


---
 lisp/org-html.el |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/lisp/org-html.el b/lisp/org-html.el
index eecda0d..5e5ec95 100644
--- a/lisp/org-html.el
+++ b/lisp/org-html.el
@@ -1820,7 +1820,7 @@ lang=\"%s\" xml:lang=\"%s\">
                    (if org-par-open "</p>\n" "")
                    (if label (format "id=\"%s\" " label) "")))
        (format "<img src=\"%s\"%s />"
-               src
+               (org-export-html-image-to-data-uri src)
                (if (string-match "\\<alt=" (or attr ""))
                    (concat " " attr )
                  (concat " " attr " alt=\"" src "\"")))
@@ -1830,6 +1830,16 @@ lang=\"%s\" xml:lang=\"%s\">
                (concat "\n<p>" caption "</p>")
                (if org-par-open "\n<p>" ""))))))))

+(defun org-export-html-image-to-data-uri (src)
+  "Load an image file and convert it to a data: URI.
+See http://en.wikipedia.org/wiki/Data_URI_scheme"
+  (with-temp-buffer
+    (insert-file-contents src)
+    (base64-encode-region (point-min) (point-max))
+    (goto-char 1)
+    (insert "data:;base64,")
+    (buffer-string)))
+
 (defun org-export-html-get-bibliography ()
   "Find bibliography, cut it out and return it."
   (catch 'exit
-- 
1.7.0.4

  reply	other threads:[~2010-09-03 15:53 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-14  6:09 MathJax is now the default for HTML math Carsten Dominik
2010-08-14 19:37 ` Jan Böcker
2010-08-14 20:39   ` Detlef Steuer
2010-08-14 20:59   ` Carsten Dominik
2010-08-14 22:16     ` Jan Böcker
2010-08-15  7:25       ` Carsten Dominik
2010-08-15 13:24       ` Jan Böcker
2010-08-16  8:59         ` Carsten Dominik
2010-08-16 10:05           ` Detlef Steuer
2010-08-16 17:55             ` Bastien
2010-08-16 10:09           ` Jan Böcker
2010-08-16 10:33             ` Carsten Dominik
2010-08-17 10:44               ` Jan Böcker
2010-08-17 11:01                 ` Carsten Dominik
2010-08-17 15:17                   ` Jan Böcker
2010-08-20 16:14                     ` Carsten Dominik
2010-09-03  3:07   ` sand
2010-09-03 15:53     ` Jan Böcker [this message]
2010-09-26 18:51       ` Embedding images as data: URIs in the HTML exporter (was: MathJax is now the default for HTML math) David Maus
2010-08-16 17:50 ` MathJax is now the default for HTML math Bastien

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