TinyMCE fetch remote images to local

tinymce-fetch-remote-img.js

editor.on('PastePostProcess', (e) => {
  setTimeout(async () => {
    const doc = new DOMParser().parseFromString(editor.getContent(), `text/html`);
    const promises = [];

    for (const img of doc.querySelectorAll('img')) {
      const src = img.src;

      const p = new Promise((resolve) => {
        fetch(src)
          .then(response => response.blob())
          .then(blob => {
            const reader = new FileReader() ;
            reader.addEventListener('load', () => {
              img.src = reader.result;
              resolve();
            });
            reader.readAsDataURL(blob) ;
          });
      });

      promises.push(p);
    }

    await Promise.all(promises);

    // Keep cursor position and replace
    const bookmark = editor.selection.getBookmark(2, true);
    editor.setContent(doc.body.innerHTML);
    editor.selection.moveToBookmark(bookmark);
  }, 0);
});