Can I bind POCO's to Elasticsearch hits for stronger typing?

Question

Tweets in an index can have a structure like this (not strict JSON, just trying to convey the structure:)

{
  text: string
  created_at: DateTime
  mention: [
    {
      name: string
      screen_name: string
      start: int
      end: int
    }
  ],
  hashtag: [
    // multiple string/int props similar to mention
  ],
  link: [
    // multiple string/int props similar to mention
  ],
  user: {
    name: string
    screen_name: string
    profile_image_url: string
  }
}

I'm getting the expected hits when using the NEST client, but I was under the impression I could map POCO's to bind the results to get some stronger typing e.g.

public class TweetDocument
{
  public string text { get; set; }
  public DateTime created_at { get; set; }
  public List<Mention> mention { get; set; }
  public List<Hashtag> hashtag { get; set; }
  public List<Link> link { get; set; }
  public User user { get; set; }
}

public class Mention
{
  public string name { get; set; }
  public string screen_name { get; set; }
  public int start { get; set; }
  public int end { get; set; }
}

// ... other POCO's for Hashtag, Link and User

The string property text and DateTime property created_at bind ok, but the mention, hashtag and link properties are all null when I look at the response's hits e.g.

var response = client.Search<TweetDocument>(q);
var firstHit = response.Hits.Hits.FirstOrDefault();
// firstHit.Fields.hashtag, .mention, .link and .user are all null

I've seen some attributes, but haven't really figured out how to use them e.g. ElasticProperty and ElasticType. How do I populate these collections from my index including the non-collection .User child property?

Answer 1

You should totally be able to bind those.

Unless when you specify the .Fields() property in your .Search()

What happens is that your document will live under _source if you don't specify Fields the hits wil return the _source if you specify fields it will return the fields as an array i.e:

 fields: {
    mention.name: ["name1", "name2"]
 }

which is basically a flattened view of your original _source document.

It would help if you can paste result.ConnectionStatus.Result to see how your results look like.