Elastic Search field selection and arrays

gistfile1.sh

# Create the first document, create a mapping
$ curl -s -X POST http://localhost:9200/test/cat -d '
{
  "title": "Kittens",
  "images": [
    {
      "caption": "O HAI"
    },
    {
      "caption": "I can has cheezburgr"
    }
  ]
}'

# The new mapping
$ curl -s 'http://localhost:9200/test/cat/_mapping?pretty=1'
{
  "cat" : {
    "properties" : {
      "title" : {
        "type" : "string"
      },
      "images" : {
        "dynamic" : "true",
        "properties" : {
          "caption" : {
            "type" : "string"
          }
        }
      }
    }
  }
}

# Query without fields specified
$ curl -s 'http://localhost:9200/test/_search?pretty=1'
...
"_source" : 
{
  "title": "Kittens",
  "images": [
    {
      "caption": "O HAI"
    },
    {
      "caption": "I can has cheezburgr"
    }
  ]
}

# Query with fields specified
$ curl -s 'http://localhost:9200/test/_search?pretty=1' -d '
{
  "fields": ["title", "images"]
}'
...
"fields" : {
        "title" : "Kittens"
}

# Query with fields specified using '_source'
$ curl -s 'http://localhost:9200/test/_search?pretty=1' -d '
{
  "fields": ["title", "_source.images"]
}'
...
"fields" : {
        "title" : "Kittens",
        "_source.images" : [ {
          "caption" : "O HAI"
        }, {
          "caption" : "I can has cheezburgr"
        } ]
}

# There is no way to select fields within images. None of these
# works:
#  * "fields": ["title", "caption"]
#  * "fields": ["title", "images.caption"]
#  * "fields": ["title", "_source.images.caption"]