Computed & Action Fields

Four field types nobody types a value into. Three are derived — the engine computes them from other data — and one is a control that runs something when clicked. All share the base field properties.

For the value-holding types — json, array, color, code, geolocation, barcode — see Structured & Media Fields.

formula

Computes a value from an expression referencing other fields.

- { id: 1, name: total_price, type: formula, formula: 'price * quantity', resultType: number }

Money computed by a formula

A formula over currency fields is money, but it does not inherit the currency of the fields it references — an expression may touch several fields or none, so there is nothing to inherit from without guessing. Declare the code:

- id: 12
  name: unit_price
  type: currency
  currency: EUR
  precision: 2
- id: 27
  name: stock_value
  type: formula
  formula: unit_price * stock_on_hand
  resultType: number
  format: currency
  currency: EUR

Omit currency and the amount renders with the USD default — which is why stock_value used to print $224,430.90 in the column beside the €28.63 it was computed from.

The five display properties are the same ones a currency field accepts, and they behave identically.

count

Counts records linked through a relationship field in the same table. A simplified rollup.

- {
    id: 2,
    name: completed_task_count,
    type: count,
    relationshipField: tasks,
    filters: { field: status, operator: equals, value: completed },
  }

autonumber

A database-assigned auto-incrementing integer — the field type behind invoice and order references. The column is a sequence, so the value is allocated by the database on insert and is never supplied by the client.

- { id: 3, name: invoice_number, type: autonumber }

That produces 1, 2, 3, and so on. autonumber takes no options: there is no prefix, no starting offset, and no zero-padding. For a human-facing reference like INV-01000, add a formula field that composes the number with the prefix and padding you want — that keeps the presentation in one place and leaves the underlying sequence untouched.

button

An interactive button rendered on records.

- {
    id: 4,
    name: approve,
    type: button,
    label: Approve,
    action: automation,
    automation: approve_request,
  }

action is a closed two-value vocabulary. action: url demands url; action: automation demands automation. Any other value — including an empty string — is rejected at startup, because action is the dispatch key both the renderer and the invoke endpoint switch on: a value neither recognises would render a button that does nothing.

The automation it names must have a manual trigger to be invocable this way.

Showing a button on some records only

visibleWhen names a record field and applies the shared condition vocabulary (eq, neq, in, notIn, contains, gt, lt, gte, lte) to its value. Supply several operators and all must hold. This is the same grammar a data-table action uses, so "show this control on some records" reads the same wherever you write it.

- {
    id: 5,
    name: ship,
    type: button,
    label: Ship,
    action: automation,
    automation: ship_order,
    visibleWhen: { field: status, eq: pending },
  }

json

Moved to Structured & Media Fields.

array

Moved to Structured & Media Fields.

color

Moved to Structured & Media Fields.

code

Moved to Structured & Media Fields.

geolocation

Moved to Structured & Media Fields.

barcode

Moved to Structured & Media Fields.

Related Pages

• Structured & Media Fields — json, array, color, code, geolocation, barcode.
• Field Types Overview — every field type by category.
• Relational Fields — the relationships count counts, plus rollup and lookup.
• Tables Overview — the base properties every field shares.