one-click-accessibility/modules/scanner/assets/js/hooks/use-prevent-aria-hidden.js

79 lines
2.1 KiB
JavaScript

import { useLayoutEffect, useRef } from '@wordpress/element';
/**
* Prevents MUI's ModalManager from adding aria-hidden="true" to document.body
* children. Inside a shadow root the ModalManager can't associate the modal
* with its shadow host, so it inadvertently hides the shadow host (and
* therefore the dialog itself) from screen readers.
*
* MUI sets aria-hidden via a ref callback during React's commit phase, before
* any effects run. We capture a snapshot of pre-existing aria-hidden state
* during render (before commit), then use useLayoutEffect to clean up what MUI
* added and attach an observer for any future mutations.
*
* MUI issue: https://github.com/mui/material-ui/issues/19450
*
* @param {boolean} active
*/
const usePreventAriaHidden = (active) => {
const snapshot = useRef(null);
// Capture which body children already have aria-hidden during the render
// phase, before React's commit phase where MUI's ref callbacks fire.
if (active && snapshot.current === null) {
const preserved = new Set();
for (const child of document.body.children) {
if (child.getAttribute('aria-hidden') !== null) {
preserved.add(child);
}
}
snapshot.current = preserved;
}
if (!active) {
snapshot.current = null;
}
useLayoutEffect(() => {
if (!active) {
return;
}
const preserved = snapshot.current || new Set();
const strip = (element) => {
if (
!preserved.has(element) &&
element.getAttribute('aria-hidden') === 'true'
) {
element.removeAttribute('aria-hidden');
}
};
const observer = new MutationObserver((mutations) => {
for (const mutation of mutations) {
if (mutation.attributeName === 'aria-hidden') {
strip(mutation.target);
}
}
});
for (const child of document.body.children) {
observer.observe(child, {
attributes: true,
attributeFilter: ['aria-hidden'],
});
// Clean up aria-hidden that MUI already set via ref callbacks
// during the commit phase (before this layout effect ran).
strip(child);
}
return () => {
observer.disconnect();
};
}, [active]);
};
export default usePreventAriaHidden;