forgejo/web_src/js/markup/anchors.js
silverwind c97a7b8347
Small refactors in anchors.js (#29947)
Some minor refactors, remove unnecessary `:is` selector and move the
`:target` check out of the function. Might as well backport for the rare
browser that does not support `:is`.

(cherry picked from commit 29118743a58cf3172bddb6a4fa287484c62b4eb1)
2024-03-26 19:04:27 +01:00

71 lines
2.4 KiB
JavaScript

import {svg} from '../svg.js';
const addPrefix = (str) => `user-content-${str}`;
const removePrefix = (str) => str.replace(/^user-content-/, '');
const hasPrefix = (str) => str.startsWith('user-content-');
// scroll to anchor while respecting the `user-content` prefix that exists on the target
function scrollToAnchor(encodedId) {
if (!encodedId) return;
const id = decodeURIComponent(encodedId);
const prefixedId = addPrefix(id);
let el = document.getElementById(prefixedId);
// check for matching user-generated `a[name]`
if (!el) {
const nameAnchors = document.getElementsByName(prefixedId);
if (nameAnchors.length) {
el = nameAnchors[0];
}
}
// compat for links with old 'user-content-' prefixed hashes
if (!el && hasPrefix(id)) {
return document.getElementById(id)?.scrollIntoView();
}
el?.scrollIntoView();
}
export function initMarkupAnchors() {
const markupEls = document.querySelectorAll('.markup');
if (!markupEls.length) return;
for (const markupEl of markupEls) {
// create link icons for markup headings, the resulting link href will remove `user-content-`
for (const heading of markupEl.querySelectorAll('h1, h2, h3, h4, h5, h6')) {
const a = document.createElement('a');
a.classList.add('anchor');
a.setAttribute('href', `#${encodeURIComponent(removePrefix(heading.id))}`);
a.innerHTML = svg('octicon-link');
heading.prepend(a);
}
// remove `user-content-` prefix from links so they don't show in url bar when clicked
for (const a of markupEl.querySelectorAll('a[href^="#"]')) {
const href = a.getAttribute('href');
if (!href.startsWith('#user-content-')) continue;
a.setAttribute('href', `#${removePrefix(href.substring(1))}`);
}
// add `user-content-` prefix to user-generated `a[name]` link targets
// TODO: this prefix should be added in backend instead
for (const a of markupEl.querySelectorAll('a[name]')) {
const name = a.getAttribute('name');
if (!name) continue;
a.setAttribute('name', addPrefix(a.name));
}
for (const a of markupEl.querySelectorAll('a[href^="#"]')) {
a.addEventListener('click', (e) => {
scrollToAnchor(e.currentTarget.getAttribute('href')?.substring(1));
});
}
}
// scroll to anchor unless the browser has already scrolled somewhere during page load
if (!document.querySelector(':target')) {
scrollToAnchor(window.location.hash?.substring(1));
}
}