Unable to add an empty array of embedded entities with different hrefs

[brabster]

Hi,

Issue https://github.com/bleupen/halacious/issues/58 allows empty arrays of embedded entities, but I can't see how to use it where I need to map objects that have self-refs defined by their own properties (eg. '/people/{id}') in an array that might be empty.

I think I'm looking for rep.embed to support an array-arg based variant (like rep.link) such as embed(rel, embeddables) where toEmbed is an object with self and entity properties. Then, I can call

rep.embed('friends', rawFriendsArray.map(function(friend) {
  var selfHref = '/people/'+friend.id;
  delete friend.id; 
  return {self: selfHref, entity: friend};
}));

...and rawFriendsArray happens to be empty it'll just embed an empty array.

Happy to submit a PR for this if I'm not missing a better way to do it already!

[bleupen]

i like that idea. You can do this easily already in route configuration, but its more difficult programmatically:

{
   handler: function(req, reply) {
      reply({ name: 'John Doe', friends: ['Jane', 'Moe', 'Play']}
   },
   plugins: {
      hal: {
         friends: {
            path: 'friends',
            href: '/people/{item.id}'
         }
      }
   }
}

[brabster]

Cheers - hopefully will get a few minutes to put something together...

[brabster]

Implementing was trickier than I expected - maybe needs a bit of callback acrobatics to embed the entity and still provide access to the representation to configure links, not enough time!

But I found a workaround... embed an array with the right rel first.

rep.embed('friends', 'whatever-its-empty', []);
rep.entity.friends.forEach(function(friend) {
  var friendRep = rep.embed('friends', '/friends/'+friend.id, friend);
  friendRep.link('unfriend', './unfriend');
  friendRep.ignore('id');
});

Feels a bit hacky but it means that the rep will have an _embedded.friends that is an array regardless of how many friends there are at runtime.

Happy to close this off.