From 744777a6a089f5b5c61255edda91a05babac93cf Mon Sep 17 00:00:00 2001 From: Ryan Ernst Date: Tue, 20 Mar 2018 22:15:34 -0700 Subject: [PATCH] Docs: Add note about missing mapping for doc values field (#29036) This commit adds a documentation note about the behavior when trying to access docvalues for a field which does not exist in mappings. closes #22056 --- docs/reference/modules/scripting/fields.asciidoc | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/docs/reference/modules/scripting/fields.asciidoc b/docs/reference/modules/scripting/fields.asciidoc index 1225d16333f..bdd6c5785d8 100644 --- a/docs/reference/modules/scripting/fields.asciidoc +++ b/docs/reference/modules/scripting/fields.asciidoc @@ -115,6 +115,17 @@ Doc-values can only return "simple" field values like numbers, dates, geo- points, terms, etc, or arrays of these values if the field is multi-valued. It cannot return JSON objects. +[NOTE] +.Missing fields +=================================================== + +The `doc['field']` will throw an error if `field` is missing from the mappings. +In `painless`, a check can first be done with `doc.containsKey('field')` to guard +accessing the `doc` map. Unfortunately, there is no way to check for the +existence of the field in mappings in an `expression` script. + +=================================================== + [NOTE] .Doc values and `text` fields ===================================================