Extends

extends lets you add custom info to field metadata. It accepts either a static object or a function that receives context.

The return type of extends is governed by the FieldExtends generic to match your custom field shape.

Type definition

(arg: {
  /**
   * The current field meta.
   */
  field: AnyResolvedFieldMeta
  /**
   * All fields meta in the form.
   */
  fields: AnyResolvedFieldsMeta
  /**
   * Current field value.
   */
  value: TFieldValue
  /**
   * Full form values.
   */
  values: TTopFormData
  /**
   * Closest array value if the field is inside an array.
   */
  closestArrayValue?: TClosestFieldArrayValue
  /**
   * The indices of the array(s) that this field is in.
   */
  indices: number[]
}) => TFieldExtends

Usage

Static object

const meta = defineFields({
  username: {
    type: 'input',
    schema: string(),
    extends: {
      label: 'Username',
      icon: 'i-lucide-user',
    },
  },
})

Dynamic function

const meta = defineFields({
  age: {
    type: 'input',
    schema: number(),
    extends({ value }) {
      return {
        label: 'Age',
        tone: value >= 60 ? 'warning' : 'normal',
      }
    },
  },
})

In array fields

Use indices and closestArrayValue to tailor per item:

const meta = defineFields({
  items: {
    nested: 'array',
    subfields: {
      name: {
        type: 'input',
        extends({ indices }) {
          return { label: `Item ${indices.at(-1)! + 1}` }
        },
      },
    },
  },
})