[[painless-filter-context]]
=== Filter context

Use a Painless script as a {ref}/query-dsl-script-query.html[filter] in a
query to include and exclude documents.


*Variables*

`params` (`Map`, read-only)::
        User-defined parameters passed in as part of the query.

`doc` (`Map`, read-only)::
        Contains the fields of the current document where each field is a
        `List` of values.

*Return*

`boolean`::
        Return `true` if the current document should be returned as a result of
        the query, and `false` otherwise.


*API*

The standard <<painless-api-reference, Painless API>> is available.

*Example*

To run this example, first follow the steps in
<<painless-context-examples, context examples>>.

This script finds all unsold documents that cost less than $25.

[source,Painless]
----
doc['sold'].value == false && doc['cost'].value < 25
----

Defining `cost` as a script parameter enables the cost to be configured
in the script query request. For example, the following request finds
all available theatre seats for evening performances that are under $25.

[source,console]
----
GET seats/_search
{
  "query": {
    "bool": {
      "filter": {
        "script": {
          "script": {
            "source": "doc['sold'].value == false && doc['cost'].value < params.cost",
            "params": {
              "cost": 25
            }
          }
        }
      }
    }
  }
}
----
// TEST[setup:seats]
