Does shr support HTML directional attributes?

Does shr support HTML directional attributes?

[Eli Zaretskii]

I've just got a (spam) mail in Arabic whose portions were displayed
left-aligned, which is not what the HTML payload wanted (it used
dir=RTL and style='margin-right:.5in;text-align:right...'), which
AFAIU should have caused the text rendered as right-to-left paragraph.

Does shr support these attributes?

Re: Does shr support HTML directional attributes?

[Lars Magne Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

> I've just got a (spam) mail in Arabic whose portions were displayed
> left-aligned, which is not what the HTML payload wanted (it used
> dir=RTL and style='margin-right:.5in;text-align:right...'), which
> AFAIU should have caused the text rendered as right-to-left paragraph.
>
> Does shr support these attributes?

Nope; shr doesn't support the "dir" attribute in elements.  I think
there used to be support for the text-align style attribute in <td>
cells, but looking at shr.el now, that seems to have been lost during
the variable-width font rewrite.

shr is a pretty minimal HTML renderer -- it tries to be fast enough for
most web pages, but it doesn't try very hard to be an accurate HTML
renderer.  There's tons of stuff it doesn't support, because it'd be too
slow.  If you find a way to support those two elements without affecting
the general rendering speed, please go ahead and add support for them.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Re: Does shr support HTML directional attributes?

[Eli Zaretskii]

> From: Lars Magne Ingebrigtsen <larsi@gnus.org>
> Cc: emacs-devel@gnu.org
> Date: Tue, 05 May 2015 02:59:43 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > I've just got a (spam) mail in Arabic whose portions were displayed
> > left-aligned, which is not what the HTML payload wanted (it used
> > dir=RTL and style='margin-right:.5in;text-align:right...'), which
> > AFAIU should have caused the text rendered as right-to-left paragraph.
> >
> > Does shr support these attributes?
> 
> Nope; shr doesn't support the "dir" attribute in elements.

It looked like that, thanks for confirming.

> shr is a pretty minimal HTML renderer -- it tries to be fast enough for
> most web pages, but it doesn't try very hard to be an accurate HTML
> renderer.  There's tons of stuff it doesn't support, because it'd be too
> slow.  If you find a way to support those two elements without affecting
> the general rendering speed, please go ahead and add support for them.

To render this correctly, we should simply insert the appropriate
directional control characters.  E.g., this page:

  http://www.w3.org/International/questions/qa-bidi-unicode-controls

provides part of the story (look under "Correspondences").  It's not
the whole story, because text-align:right is not covered, but
supporting that is similarly simple.

Would it help if I provide an algorithmic description of what needs to
be done?

Re: Does shr support HTML directional attributes?

[Lars Magne Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

> Would it help if I provide an algorithmic description of what needs to
> be done?

Sure; that would be helpful.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no