Entry representing a collected derivation from field definitions.

Created during form initialization when traversing field definitions to collect all derivation rules (both shorthand and full logic configs).

All derivations are self-targeting: the fieldKey is both where the derivation is defined AND where the computed value will be set.

Properties

Name	Type	Description
condition	`boolean \| ConditionalExpression`	Condition that determines when this derivation applies. Defaults to `true` (always apply) if not specified.
debounceMs	`number \| undefined`	Debounce duration in milliseconds. Only used when `trigger` is 'debounced'. @default 500
debugName	`string \| undefined`	Optional debug name for easier identification in logs. Copied from the originalConfig if provided. When set, this name appears in verbose derivation logs instead of the field key.
dependsOn	`string[]`	Field keys that this derivation depends on. Extracted from conditions and expressions. Used for: Cycle detection Reactive dependency tracking Determining evaluation order
expression	`string \| undefined`	JavaScript expression to evaluate for the derived value. Mutually exclusive with `value` and `functionName`.
fieldKey	`string`	The key of the field where this derivation is defined and targets. Derivations always target the field they are defined on (self-targeting). For array fields, this may include a placeholder path like 'items.$.lineTotal' which is resolved to actual indices at runtime.
functionName	`string \| undefined`	Name of a registered custom derivation function. Mutually exclusive with `value` and `expression`.
isShorthand	`boolean`	Whether this derivation was created from the shorthand `derivation` property. Shorthand derivations use a string expression directly on the field.
originalConfig	`DerivationLogicConfig \| undefined`	The original logic config if this entry was created from a full logic config.
trigger	`LogicTrigger`	When to evaluate the derivation. `onChange`: Evaluate immediately when dependencies change (default) `debounced`: Evaluate after value has stabilized for debounceMs @default 'onChange'
value	`unknown`	Static value to set on this field. Mutually exclusive with `expression` and `functionName`.