Add an array field type to Custom Objects

[bctiemann]

Plugin Version

v0.6.0

Proposed functionality

Add a first-class array field type, backed by Postgres/Django's ArrayField (including support for nested arrays with a fixed element size), with an element schema — distinct from the existing unstructured json field type, which doesn't validate shape and can't be filtered positionally. Today the Custom Objects field-type enum has no array type.

Use case

netbox-physical-geometry's Zone and Path models store geometry as a nested array of (x, y, z) integer triplets:

coordinates = ArrayField(
    ArrayField(models.PositiveIntegerField(), size=3),  # (x, y, z) coords for each point
    validators=[MinLengthValidator(2)],
)

The existing coordinates field type (added in v0.6.0) only covers a single lat/lon pair and doesn't cover a variable-length list of coordinate triplets. This is a lower-priority, narrower gap — only 1 of 9 surveyed plugins is affected, and it's a fairly geometric outlier — but a first-class array type with an element schema would close this gap and would likely be more broadly useful than a one-off geometry-specific field.

External dependencies

None — reuses Postgres/Django's existing ArrayField support.