dpvc
commented
9 months ago I wasn't able to reproduce in Firefox, but did see it in Chrome and Safari.
It took a bit of digging, but it turns out that the typeset: false was also a significant part of the problem. It turns out that when the startup typeset is shipped, the metrics need for the typesetting (e.g., the ex and em sizes) aren't computed, and when the math is then processed by the lazy loader, the values for ex and em are not defined, and the results produce the NaN values you re seeing. That means the final SVG is not properly scaled. The AssistiveMml extension plays a role because it requires the speech-rule engine to be set up, and that is done in a promise, so some code runs before that is processed, and MathJax thinks the metrics have been obtained when they haven't.
This code will work around the problem for now:
MathJax = {
loader: { load: [ 'ui/lazy' ] },
options: {
lazyAlwaysTypeset: '.disable-lazy-typesetting',
menuOptions: { settings: { assistiveMml: true } },
},
output: { font: 'https://cdn.jsdelivr.net/npm/mathjax-tex-font@1.0.0-alpha.1/es5/output/fonts/mathjax-tex' },
startup: {
typeset: false,
ready() {
const {AbstractMathItem, STATE} = MathJax._.core.MathItem;
Object.assign(AbstractMathItem.prototype, {
__state: AbstractMathItem.prototype.state,
state(state, restore) {
if (state === STATE.TYPESET - 1 && !this.metrics.hasOwnProperty('em')) {
state = STATE.METRICS - 1;
}
return this.__state(state, restore);
}
});
MathJax.startup.defaultReady();
}
},
};but I will make a PR to fix the issue in the next release.
For me, Firefox doesn't process the math when typeset: false is in play, but Chrome and Safari do. I'm trying to decide what the proper behavior should be for the lazy loader, but all three browser should really do the same thing, I would think. The typeset: false really should prevent any typesetting until the first time MathJax.typeset or MathJax.typesetPromise() is called. I'm not sure why Safari and Chrome are doing the typesetting, and will have to look into that. It is probably the the IntersectionObserver fires in one case and not the other.
AlexEdgcomb
Issue Summary
Having both assistive MML and lazy typesetting causes enormous typesettings
Steps to Reproduce:
Expected: Typesetting is normal size
Console warnings:
No console error.
Technical details:
I am using the following MathJax configuration:
and loading MathJax via
Supporting information:
Also confirmed to reproduce in: