Compact

Mutate Mezmo Compatible

Synopsis

Removes null values, empty and whitespace-only strings, empty arrays, and empty objects recursively.

Schema

- compact:
    values: <array>
    excluded_fields: <array>
    description: <text>
    if: <script>
    ignore_failure: <boolean>
    on_failure: <processor[]>
    on_success: <processor[]>
    tag: <string>

Configuration

The following fields are used to define the processor:

Field	Required	Default	Description
values	N	-	Array of values to be removed when found, in addition to empty fields
excluded_fields	N	-	Array of field names to exclude from compaction
description	N	-	Explanatory note
if	N	-	Condition to run
ignore_failure	N	false	See Handling Failures
on_failure	N	-	See Handling Failures
on_success	N	-	See Handling Success
tag	N	-	Identifier
disabled	N	false	When true, the processor is skipped and the event continues to the next one. Lets you take a processor out of the path without removing its configuration

Details

Empty fields include null values, empty strings, empty arrays [], and empty objects {}. This processor helps reduce the document size and improve readability by eliminating all the unnecessary fields.

A string of nothing but whitespace counts as empty. A field holding " " or a lone tab is dropped exactly as "" is, so a padded field that a parser left behind does not survive as a value that merely looks blank.

note

The processor is particularly useful for cleaning up documents before storage or transmission, reducing storage space and network bandwidth usage.

Examples

Basic

Remove empty fields from document...	{ "name": "document1", "tags": [], "metadata": {}, "description": "", "status": null, "value": 42 } - compact: description: "Remove empty fields"
resulting in only non-empty fields:	{ "name": "document1", "value": 42 }

Nested Objects

Process nested objects recursively...	{ "user": { "name": "John", "settings": { "theme": "", "notifications": {}, "preferences": { "language": "en" } }, "groups": [] } } - compact: description: "Clean user data"
removing empty fields at all levels:	{ "user": { "name": "John", "settings": { "preferences": { "language": "en" } } } }

Specific Values

Remove empty fields and...	{ "status": "pending", "priority": "low", "tags": ["draft", "review", ""], "metadata": {} } - compact: values: ["low", "draft"]
specific values:	{ "status": "pending", "tags": ["review"] }

Conditionals

Compact only when a condition is met...	{ "type": "user", "data": { "id": "123", "roles": [], "settings": {} } } - compact: if: "ctx.type == 'user'"
only user documents are compacted:	{ "type": "user", "data": { "id": "123" } }