cal.pub0.org/packages/lib/defaultAvatarImage.ts

/**
 * Given an avatar URL and a name, return the appropriate avatar URL. In the
 * event that no avatar URL is provided, return a placeholder avatar URL from
 * ui-avatars.com.
 *
 * ui-avatars.com is a free service that generates placeholder avatars based on
 * a name. It is used here to provide a consistent placeholder avatar for users
 * who have not uploaded an avatar.
 */
export function getPlaceholderAvatar(avatar: string | null | undefined, name: string | null | undefined) {
  return avatar
    ? avatar
    : "https://eu.ui-avatars.com/api/?background=fff&color=f9f9f9&bold=true&background=000000&name=" +
        encodeURIComponent(name || "");
}