katex
Version:
Fast math typesetting for the web.
25 lines (23 loc) • 943 B
JavaScript
import katexReplaceWithTex from './katex2tex';
// Global copy handler to modify behavior on .katex elements.
document.addEventListener('copy', function(event) {
const selection = window.getSelection();
if (selection.isCollapsed) {
return; // default action OK if selection is empty
}
const fragment = selection.getRangeAt(0).cloneContents();
if (!fragment.querySelector('.katex-mathml')) {
return; // default action OK if no .katex-mathml elements
}
// Preserve usual HTML copy/paste behavior.
const html = [];
for (let i = 0; i < fragment.childNodes.length; i++) {
html.push(fragment.childNodes[i].outerHTML);
}
event.clipboardData.setData('text/html', html.join(''));
// Rewrite plain-text version.
event.clipboardData.setData('text/plain',
katexReplaceWithTex(fragment).textContent);
// Prevent normal copy handling.
event.preventDefault();
});