Re: Strange latex symbol behavior on html export

[Rasmus <rasmus@gmx.us>]

Nick Dokos <ndokos@gmail.com> writes:

> Lawrence Bottorff <borgauf@gmail.com> writes:
>
>> ... I use
>>
>> # this makes MathJax work
>> #+OPTIONS: tex:t
>>
>> I just now found this caption weirdness because I started a new .org
>> file with no latex symbol markup besides in the caption. Quite
>> bizarre that when my file sees other latex symbols, the caption
>> symbols then render correctly. 
>>
>
>> On Wed, Sep 13, 2017 at 6:55 PM, Nick Dokos <ndokos@gmail.com> wrote:
>>
>>     Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:
>>    
>>     > Hello,
>>     >
>>     > Lawrence Bottorff <borgauf@gmail.com> writes:
>>     >
>>     >> Consider this markup:
>>     >>
>>     >> ------------
>>     >> * MATHEMATICS AUXILIARY
>>     >>
>>     >> ** deriving sines and cosines
>>     >>
>>     >> #+caption: Right triangle with two $\pi\big/4$ angles.
>>     >> [[file:images/45-45-triangle.png]]
>>     >>
>>     >> $\big/$
>>     >> ------------
>>     >>
>>     >> If I remove the second $\big/$, the first latex, $\pi\big/4$, in the
>>     >> caption will not properly render on export to html. Include it and both
>>     >> render just fine. Without the second, the first looks like this:
>>     >>
>>     >> Figure 1: Right triangle with two \(\pi\big/4\) angles.
>>     >>
>>     >> Is this a bug?
>>     >
>>     > If you use
>>     >
>>     >   #+options: tex:dvipng
>>     >
>>     > the symbol in the caption is correctly rendered. It may be a bug in Mathjax.
>>     >
>>    
>>     I looked at the diff between html files produced with and without the $\big/$ addition.
>>     The one without does not include any of the mathjax configuration code at all. Is that
>>     code included conditionally perhaps when a latex construct is seen? Maybe the latex construct
>>     in the caption does not trigger the inclusion?
>>    
>>     --
>>     Nick
>>
>
> org-html--build-mathjax-config includes the mathjax code only if
>
>   (and (memq (plist-get info :with-latex) '(mathjax t))
>        (org-element-map (plist-get info :parse-tree)
> 		 '(latex-fragment latex-environment) 'identity info t))
>
> is true.

I guess we didn’t want to load extra JS unless it’s needed.

> So if there is latex markup in the file (other than the caption) the org-element-map
> call finds it and returns non-nil, but it apparently does not look inside the caption.

When org-element looks at something like "#+caption: a $b$" it sees a
keyword.  I don’t know if it’s possible to check explicitly whether it
contains maths.  Alternatively, we could check if :with-latex is
explicitly set in the buffer (like in ox-koma-letter) and then load it
regardless.

Rasmus

-- 
This is the kind of tedious nonsense up with which I will not put