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• Spatialized.io (Elasticsearch & Google Maps consulting)
• in cooperation with Garages-Near-Me.com (Effortless long-term parking across Germany)

Scripting enables you to evaluate custom expressions.

As explored in 2. Insertion & Ingestion, we can modify fields.

And as mentioned in Points Closest to the Origin, we can dynamically score documents and calculate new values on-the-fly.

Scripts can be used in various contexts but are leveraged most often:

• during updates and reindexing
• in queries and aggregations where there are no alternatives (like here)
• and when sorting.

How to Use Scripts

The default scripting language is [Painless](<https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-scripting-painless.html>). Additional lang plugins enable you to run scripts written in other languages. Everywhere a script can be used, you can include a lang parameter to specify the language of the script.

Supported Languages

• ~~groovy~~ — slow and discontinued
• painless — a sandboxed and secure general-purpose language extending a subset of Java’s syntax; offers optional typing through the def keyword
• [expression](<https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-scripting-expression.html>) — Lucene expressions — a sandboxed, javascript-like language used for fast custom ranking and sorting but limited to only numeric, boolean, date, and geo_point fields
• [mustache](<https://www.elastic.co/guide/en/elasticsearch/reference/current/search-template.html>) — used in (search) templates. Here's an example.
• and good old java — supporting lower-level script engine modules

Script Syntax