Linux HTML mail agent with RTL and LTR paragraph explicit support

[Shachar Shemesh]

On 06/24/2012 10:40 PM, Dotan Cohen wrote:
> On Sun, Jun 24, 2012 at 7:30 PM, Shachar Shemesh <shachar at shemesh.biz> wrote:
>> There is a standard way to specify paragraph directionality in emails. It is
>> done through HTML. There is a standard way in HTML to specify
>> directionality. Unless a recent proposed change to HTML5 is accepted, the
>> first directional character of the paragraph is not it.
>>
> I think that you mean that there is a standard way to specify
> directionality in HTML, so if one needs directionality then he should
> send HTML emails.
>
> There is a way to specify directionality in plain text, too: U+202A
> and U+202B (LTR- and RTL-Embedding characters).
I disagree completely. The embedding control characters are designed
for, well, embedding. What the standard[1] suggests, but does not
require, is the use of the first strong directional character in the
paragraph. The reasons this does not work for email are:

 1. It is not required by the standard. It is suggested as a way to
    determine paragraph directionality, but this suggestion is
    incomplete. For example, the standard says nothing about what to do
    with a paragraph with no strong directional character at all.
 2. This suggestion is non-normative. The standard explicitly states
    that a "higher level protocol" can be used to determine this property.
 3. HTML has chosen the "higher level property" as the BiDi
    directionality path. Unless certain discussions currently in effect
    become standard, HTML will not guess the directionality of a
    paragraph ever, no matter how much you want it to. There are some
    discussions about adding a "direction: auto" property to CSS.
 4. The only standard way to provide paragraph directionality in email
    is by sending it as HTML

A few takeaways. There is no standard I'm aware of that states you
SHOULDN'T use the first character in a paragraph to determine paragraph
direction in plain-text emails. I think that is a perfectly reasonable
approach. However, most of the world uses various MS based email
readers. Those don't do it, and they do not violate any standard by not
doing it. As a result, if you want your email to be legible by any
recipient, HTML mail is the way to go if you are writing in Hebrew.
Complaining to your recipient (or sender) that they are not doing it
properly is both impolite and, which I feel many people here will see as
worse, technically incorrect.

>
>
>> I know many people on this list don't like this standard, but this extra
>> email did nothing to change it (not that I, personally, think that changing
>> it is the right thing to do).
>>
> Are you referring to me, in regard to the discussion that we had in
> which I think that the LTR- and RTL-Embedding characters should be
> available in the Hebrew keyboard layout?
No. I am referring to all those who complain so violently when HTML mail
is sent to the list.
>  That doesn't mean that I
> dislike the idea of using HTML. Actually, I don't like HTML mail but
> not for that reason, rather a personal preference with no root in
> ideology nor technical reason.
Okay, so maybe I was referring to you after all :-)

Shachar

1 - By "the standard" I am referring here to the Unicode BiDi Algorithm,
technical report #9 of the Unicode standard.

-- 
Shachar Shemesh
Lingnu Open Source Consulting Ltd.
http://www.lingnu.com

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