Removing/Ignoring xmlns when using xml->sxml

Removing/Ignoring xmlns when using xml->sxml

[Richard Sent]

Hi all,

I have some XML created by a tool called latexml that can convert LaTeX
equations to MathML. I am processing the output of this tool as part of
a Guile program and will be using it in a website.

The output looks something like this:

--8<---------------cut here---------------start------------->8---
<math xmlns=\"http://www.w3.org/1998/Math/MathML\" alttext=\"\\frac{1}{2}\" display=\"block\">
  <mfrac>
    <mn>1</mn>
    <mn>2</mn>
  </mfrac>
</math>
--8<---------------cut here---------------end--------------->8---

I need to convert this output to SXML to integrate it with the rest of
the toolchain.

Annoyingly, when using xml->sxml, the xmlns attribute is prepended to
every non-default element. For example,
'(http://www.w3.org/1998/Math/MathML:math ...) [1].

This behavior is undesirable when splicing the MathML into HTML, since
HTML doesn't support namespaces and web browsers don't seem to handle
elements with colons. The intended conversion is to simply splice the
MathML into HTML, sans namespace [2].

xml->sxml has a #:namespaces argument that allows me to alias the URL
namespace to something else in the SXML, but it doesn't look like I can
alias it to a "nil" namespace that isn't prepended at all.

The only option I can think of is to strip the xmlns=blah string from
the XML ahead of time. (Because converting to SXML prepends every
element, that's a lot harder to fix.) This solution feels rather hacky.

Does anyone know of a better way? I don't believe latexml has an option
to force HTML-compatible MathML output for individual equations.

I'd be surprised if no one else encountered this before. Hopefully I'm
missing something. Thanks! :)

[1]: (guile) Reading and Writing XML, "SXML elements built from
non-default namespaces will have their tags prefixed with their URI."
[2]:
https://en.wikipedia.org/wiki/MathML#Embedding_MathML_in_HTML/XHTML_files

-- 
Take it easy,
Richard Sent
Making my computer weirder one commit at a time.

Re: Removing/Ignoring xmlns when using xml->sxml

[Luis Felipe]

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Hi Richard,

El 22/07/24 a las 3:11, Richard Sent escribió:
> Hi all,
>
> I have some XML created by a tool called latexml that can convert LaTeX
> equations to MathML. I am processing the output of this tool as part of
> a Guile program and will be using it in a website.
>
> The output looks something like this:
>
> --8<---------------cut here---------------start------------->8---
> <math xmlns=\"http://www.w3.org/1998/Math/MathML\" alttext=\"\\frac{1}{2}\" display=\"block\">
>    <mfrac>
>      <mn>1</mn>
>      <mn>2</mn>
>    </mfrac>
> </math>
> --8<---------------cut here---------------end--------------->8---
>
> I need to convert this output to SXML to integrate it with the rest of
> the toolchain.
>
> Annoyingly, when using xml->sxml, the xmlns attribute is prepended to
> every non-default element. For example,
> '(http://www.w3.org/1998/Math/MathML:math ...) [1].
>
> This behavior is undesirable when splicing the MathML into HTML, since
> HTML doesn't support namespaces and web browsers don't seem to handle
> elements with colons. The intended conversion is to simply splice the
> MathML into HTML, sans namespace [2].
>
> xml->sxml has a #:namespaces argument that allows me to alias the URL
> namespace to something else in the SXML, but it doesn't look like I can
> alias it to a "nil" namespace that isn't prepended at all.

The following seems to work (where xml-string is the example you provided):

(define namespaces '((#false . "http://www.w3.org/1998/Math/MathML")))

(xml->sxml xml-string #:namespaces namespaces)
$7 = (*TOP* (math (@ (display "block") (alttext "\\frac{1}{2}")) "\n  " 
(mfrac "\n    " (mn "1") "\n    " (mn "2") "\n  ") "\n"))



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Re: Removing/Ignoring xmlns when using xml->sxml

[Richard Sent]

Thanks! That works. As far as I can tell that behavior is not documented
in the manual so I'll try to send out a patch for that.

-- 
Take it easy,
Richard Sent
Making my computer weirder one commit at a time.