[[json-processor]]
=== JSON processor
++++
<titleabbrev>JSON</titleabbrev>
++++

Converts a JSON string into a structured JSON object.

[[json-options]]
.Json Options
[options="header"]
|======
| Name           | Required  | Default  | Description
| `field`        | yes       | -        | The field to be parsed.
| `target_field` | no        | `field`  | The field that the converted structured object will be written into. Any existing content in this field will be overwritten.
| `add_to_root`  | no        | false    | Flag that forces the serialized json to be injected into the top level of the document. `target_field` must not be set when this option is chosen.
include::common-options.asciidoc[]
|======

All JSON-supported types will be parsed (null, boolean, number, array, object, string).

Suppose you provide this configuration of the `json` processor:

[source,js]
--------------------------------------------------
{
  "json" : {
    "field" : "string_source",
    "target_field" : "json_target"
  }
}
--------------------------------------------------
// NOTCONSOLE

If the following document is processed:

[source,js]
--------------------------------------------------
{
  "string_source": "{\"foo\": 2000}"
}
--------------------------------------------------
// NOTCONSOLE

after the `json` processor operates on it, it will look like:

[source,js]
--------------------------------------------------
{
  "string_source": "{\"foo\": 2000}",
  "json_target": {
    "foo": 2000
  }
}
--------------------------------------------------
// NOTCONSOLE

If the following configuration is provided, omitting the optional `target_field` setting:
[source,js]
--------------------------------------------------
{
  "json" : {
    "field" : "source_and_target"
  }
}
--------------------------------------------------
// NOTCONSOLE

then after the `json` processor operates on this document:

[source,js]
--------------------------------------------------
{
  "source_and_target": "{\"foo\": 2000}"
}
--------------------------------------------------
// NOTCONSOLE

it will look like:

[source,js]
--------------------------------------------------
{
  "source_and_target": {
    "foo": 2000
  }
}
--------------------------------------------------
// NOTCONSOLE

This illustrates that, unless it is explicitly named in the processor configuration, the `target_field`
is the same field provided in the required `field` configuration.
