Sorting with a ReactiveMongo JSON query

Question

This seems crazy that I have to ask but I cannot find the right syntax to sort query result using ReactiveMongo. So if I had this:

   rCollection.flatMap(
     // find all
     _.find(Json.obj())
       // perform the query and get a cursor of JsObject
       .cursor[Resort](ReadPreference.primary)
       // Collect the results as a list
       .collect[List](Int.MaxValue, Cursor.FailOnError[List[Resort]]())
   )

How would I sort by a particularly column in descending order.

Answer 1

This would probably be:

rCollection.flatMap(
 // find all
 _.find(Json.obj())
  .sort(Json.obj())
   // perform the query and get a cursor of JsObject
   .cursor[Resort](ReadPreference.primary)
   // Collect the results as a list
   .collect[List](Int.MaxValue, Cursor.FailOnError[List[Resort]]())

)

The JSON object you send to the 'sort' function would be the same JSON you'd use in mongo query for sorting. eg:

{"age": 1, "lastName": -1}

sorts by age ascending and then lastName descending.