forgejo/web_src/js/features/clipboard.js

// For all DOM elements with [data-clipboard-target] or [data-clipboard-text], this copy-to-clipboard will work for them

// TODO: replace these with toast-style notifications
function onSuccess(btn) {
  if (!btn.dataset.content) return;
  $(btn).popup('destroy');
  btn.dataset.content = btn.dataset.success;
  $(btn).popup('show');
  btn.dataset.content = btn.dataset.original;
}
function onError(btn) {
  if (!btn.dataset.content) return;
  $(btn).popup('destroy');
  btn.dataset.content = btn.dataset.error;
  $(btn).popup('show');
  btn.dataset.content = btn.dataset.original;
}

export default function initGlobalCopyToClipboardListener() {
  document.addEventListener('click', async (e) => {
    let target = e.target;
    // in case <button data-clipboard-text><svg></button>, so we just search up to 3 levels for performance.
    for (let i = 0; i < 3 && target; i++) {
      let text;
      if (target.dataset.clipboardText) {
        text = target.dataset.clipboardText;
      } else if (target.dataset.clipboardTarget) {
        text = document.querySelector(target.dataset.clipboardTarget)?.value;
      }
      if (text) {
        e.preventDefault();
        try {
          await navigator.clipboard.writeText(text);
          onSuccess(target);
        } catch {
          onError(target);
        }
        break;
      }
      target = target.parentElement;
    }
  });
}