Structured object check types on Katalyst Documentation

Field enum

Mon, 01 Jan 0001 00:00:00 +0000

Check type ID#

kind: object_field_enum

Purpose#

Require that a field is one of a fixed set of values.

Configuration keys#

Field	Required	Default	Meaning
`field`	yes	-	Frontmatter key to check.
`values`	yes	-	Allowed values.

Example#

collections:
 notes:
 path: notes
 checks:
 - kind: object_field_enum
 field: status
 values: [draft, published, archived]

Field type

Mon, 01 Jan 0001 00:00:00 +0000

Check type ID#

kind: object_field_type

Purpose#

Require that a frontmatter field has a specific type.

Configuration keys#

Field	Required	Default	Meaning
`field`	yes	-	Frontmatter key to check.
`type`	yes	-	One of `string`, `boolean`, `array`, `object`, `number`, `integer`.

Example#

collections:
 notes:
 path: notes
 checks:
 - kind: object_field_type
 field: year
 type: integer

Worked example#

Here year is a string, not an integer. An inline object_field_type check fails the item, points at the offending field with a JSON pointer (/year) and a path:line prefix, and exits 1.

Number range

Mon, 01 Jan 0001 00:00:00 +0000

Check type ID#

kind: object_number_range

Purpose#

Constrain a numeric field to a minimum and/or maximum value.

Configuration keys#

Field	Required	Default	Meaning
`field`	yes	-	Frontmatter key to check.
`min`	no	-	Inclusive lower bound. At least one of `min`/`max` is required.
`max`	no	-	Inclusive upper bound. At least one of `min`/`max` is required.

Example#

collections:
 notes:
 path: notes
 checks:
 - kind: object_number_range
 field: year
 min: 1900
 max: 2100

Required field

Mon, 01 Jan 0001 00:00:00 +0000

Check type ID#

kind: object_required_field

Purpose#

Require that a frontmatter field exists.

Configuration keys#

Field	Required	Default	Meaning
`field`	yes	-	Frontmatter key that must be present.

Example#

collections:
 notes:
 path: notes
 checks:
 - kind: object_required_field
 field: year

Worked example#

The books collection binds the book schema (title plus an integer year). dune.md satisfies the schema and reports OK; foundation.md omits year, so check reports the missing required property and exits 1.

Sentence case

Mon, 01 Jan 0001 00:00:00 +0000

Check type ID#

kind: object_sentence_case

Purpose#

Require a string field to read as sentence case, not Title Case.

Configuration keys#

Field	Required	Default	Meaning
`field`	yes	-	Frontmatter key whose string value must be sentence case.
`allow`	no	-	Proper nouns permitted to keep a leading capital mid-title (e.g. `Katalyst`). All-caps acronyms (CI, H1) are always allowed.

Example#

collections:
 pages:
 path: docs/content
 checks:
 - kind: object_sentence_case
 field: title
 allow: [Katalyst]

String length

Mon, 01 Jan 0001 00:00:00 +0000

Check type ID#

kind: object_string_length

Purpose#

Constrain the minimum and/or maximum length of a string field.

Configuration keys#

Field	Required	Default	Meaning
`field`	yes	-	Frontmatter key to check.
`min_length`	no	-	Minimum length. At least one of `min_length`/`max_length` is required.
`max_length`	no	-	Maximum length. At least one of `min_length`/`max_length` is required.

Example#

collections:
 notes:
 path: notes
 checks:
 - kind: object_string_length
 field: title
 min_length: 3
 max_length: 120

Unique field

Mon, 01 Jan 0001 00:00:00 +0000

Check type ID#

kind: filesystem_unique_field

Scope: collection, runs once per collection over all its items.

Purpose#

Require that no two items share a value for a frontmatter field.

Configuration keys#

Field	Required	Default	Meaning
`field`	yes	-	Frontmatter key whose value must be unique across the collection.

Example#

collections:
 notes:
 path: notes
 checks:
 - kind: filesystem_unique_field
 field: slug

Object validation

Mon, 01 Jan 0001 00:00:00 +0000

Check type ID#

kind: object

Purpose#

Validate frontmatter metadata against a named JSON Schema from schemas:.

Configuration keys#

Field	Required	Default	Meaning
`schema`	yes	-	Name of an entry in `schemas:`.

Example#

schemas:
 book: ./schemas/book.json
collections:
 notes:
 path: notes
 checks:
 - kind: object
 schema: book