Images
The image feature appears only when the host wired onUploadImage. An
inserted image is a drop zone until it has a url: the picked file goes to
your callback, its result lands on the node, and a failure keeps the node and
says why. Files dropped on or pasted into the canvas become image nodes too,
one per file, each filled in as its upload lands. The callback receives the
File and resolves with { url, width?, height? }; the sizes reach the
rendered <img>.
onUploadImage={async (file) => {
const uploaded = await storage.put(file);
return { url: uploaded.publicUrl, width: uploaded.width, height: uploaded.height };
}}Every media node carries a caption, edited in place under it.
Video, files, YouTube, X
Four embed features, each an attribute form in a popover rather than a
prompt: a video url, a file url and name, a YouTube url or id, an X post url
or id. Leave any out with createContentFeatures({ embeds: ["youtube"] }).
A YouTube node renders the youtube-nocookie player; an X post renders the
blockquote X's embed script upgrades in place, so a host that loads the
script gets the card and one that does not still gets a link.