FieldContextRegistryService

Creates an evaluation context for display-only components (text fields, pages) that don't have their own FieldContext.

This is useful for:

• Text fields (display-only, not part of form schema)
• Pages (containers that need to evaluate visibility logic)

Uses reactive form value access to allow logic re-evaluation when form values change.

Presentation

createDisplayOnlyContext(fieldPath: string, customFunctions?: Record<string, (context: EvaluationContext<unknown>) => unknown> | undefined, formId: string = 'default'): EvaluationContext<unknown>;

Parameters

Returns

Creates an evaluation context for a field by combining:

• The field's current value
• The root form value from the registry
• The field path (if available from form context)
• Custom functions (if provided)

Presentation

createEvaluationContext(fieldContext: RootFieldContext<TValue>, customFunctions?: Record<string, (context: EvaluationContext<unknown>) => unknown> | undefined, formId: string = 'default'): EvaluationContext<unknown>;

Parameters

Returns

Creates a REACTIVE evaluation context for logic functions.

Unlike createEvaluationContext, this method does NOT use untracked(), which allows logic functions (hidden, readonly, disabled, required) to create reactive dependencies on form values.

When a dependent field value changes, the logic function will be re-evaluated.

IMPORTANT: For this to work correctly, the form value signal should be registered with rootFormRegistry.registerFormValueSignal() BEFORE the form is created. This ensures the logic function can read form values during schema evaluation.

NOTE: This should ONLY be used for logic functions, not validators. Validators should use createEvaluationContext with untracked() to prevent infinite reactive loops. Validators with cross-field dependencies should be hoisted to form-level using validateTree.

Presentation

createReactiveEvaluationContext(fieldContext: RootFieldContext<TValue>, customFunctions?: Record<string, (context: EvaluationContext<unknown>) => unknown> | undefined, formId: string = 'default'): EvaluationContext<unknown>;

Parameters

Returns