Return an avatar from a FirebaseSimpleLogin user object.

avatar.js

/**
 * Only CommonJS is cool
 */
module.exports = avatar

/**
 * Example:
 *   var avatar = require('avatar')
 *   var auth = new FirebaseSimpleLogin(db, function (err, user) {
 *     user.avatar = avatar(user)
 *   })
 */
function avatar (user) {
  // TODO: gravatar from email for Persona and password
  return (user.provider == 'facebook') ?
    ('http://graph.facebook.com/'+user.id+'/picture') :
    user.profile_image_url ||
    user.avatar_url
}