Automatic id generation and mapping _id NEST - elasticsearch

Question

I want the id to be automatically generated when I index a document into elastic search. This works fine when I don't specify an Id property in my poco.
What I would like to do is map the underlying _id field onto my poco class when getting and use auto generated id when indexing. It looks like I can either specify the id or not at all. Are their any nest api options that I am missing?
EDIT
Example gist
https://gist.github.com/antonydenyer/9074159

Answer 1

As #Duc.Duong said in comments you can access Id using DocumentWithMeta.
In current version of NEST DocumentsWithMetaData is replaced with Hits and also you should cast IHit<DataForGet>.Id from string to int.
this is my code:
public class DataForIndex
{
public string Name { get; set; }
// some other fields...
}
public class DataForGet : DataForIndex
{
public int Id { get; set; }
}
var result = client.Search<DataForGet>(x => x.Index("index").MatchAll());
var list = results.Hits.Select(h =>
{
h.Source.Id = Convert.ToInt32(h.Id);
return h.Source;
}).ToList();

Answer 2

Automatic ID Generation
The index operation can be executed without specifying the id. In such a case, an id will be generated automatically. In addition, the op_type will automatically be set to create. Here is an example (note the POST used instead of PUT):
$ curl -XPOST 'http://localhost:9200/twitter/tweet/' -d '{
"user" : "kimchy",
"post_date" : "2009-11-15T14:12:12",
"message" : "trying out Elasticsearch"
}'
Result:
{
"_index" : "twitter",
"_type" : "tweet",
"_id" : "6a8ca01c-7896-48e9-81cc-9f70661fcb32",
"_version" : 1,
"created" : true
}

Answer 3

Seem that NEST auto detect "Id" field in class and map it to "_id" in ES. Your requirement look strange but why not create 2 classes for it ? One for indexing (without Id field), one for getting (inherited from indexing class and declare new field "Id") ?
e.g.:
public class DataForIndex
{
public string Name { get; set; }
// some other fields...
}
public class DataForGet : DataForIndex
{
public int Id { get; set; }
}