Support for <object>s containing MathML

[cpitclaudel]

Firefox supports embedding MathML objects using the <object> tag, with mime type application/mathml+xml. Chromium doesn't support this, so it would be great to use MathJax for this.

This topic was discussed on the mailing list some time ago: https://groups.google.com/forum/#!msg/mathjax-users/5VOt3rJXHms/X1_ovYTCm5MJ, and led to a wiki page in MathJax-docs (https://github.com/mathjax/mathjax-docs/wiki/External-MathML-files-with--object--does-not-work-with-MathJax), but the solution posted there is for MathJax v2.

The feature request is for MathJax to replace <object>s with type application/mathml+xml with its own rendering.

Here is an example:

• input.mml

  <?xml version="1.0" encoding="UTF-8"?>
  <math xmlns="http://www.w3.org/1998/Math/MathML" alttext="1+2" display="block">
    <mrow>
      <mn>1</mn>
      <mo>+</mo>
      <mn>2</mn>
    </mrow>
  </math>

• HTML source code

  <object type="application/mathml+xml" data="input.mml"></object>

Alternatives: Including MathML directly works fine, but it's not as convenient for reusing math.

[dpvc]

If you are willing to change the type to type="text/html" (which renders essentially the same in Firefox, and allows other browsers to at least load the MathML document and try to display it), then you can use

<script>
MathJax = {
  options: {
    renderActions: {
      objects: [5, (doc) => {
        const objects = Array.from(document.querySelectorAll('object[type="text/html"]'));
        const jax = doc.inputJax[0];
        for (const object of objects) {
          const mml = ((object.contentDocument || {}).documentElement || {});
          if (String(mml.nodeName).toLowerCase() === "math") {
            object.parentNode.replaceChild(document.importNode(mml, true), object);
          }
        }
      }]
    }
  }
}
</script>
<script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/mml-chtml.js"></script>

to have MathJax v3 replace the objects by the MathML they contain, and then process that MathML as through it were in the main document originally.

It you leave it as type="application/mathml+xml", then it will work in Firefox (with the native Firefox MathML rendering replaced by MathJax's rendering), but will not work in Chrome or other browsers.

[cpitclaudel]

Thanks! This snippet is perfect. I have updated the wiki page.