# `MishkaGervaz.Form.Entities.NestedField`
[🔗](https://github.com/mishka-group/mishka_gervaz/blob/v0.0.1-alpha.3/lib/mishka_gervaz/form/entities/nested_field.ex#L1)

Sub-field declaration inside a `:nested` form field — used for
embedded resources and constrained `{:array, :map}` attributes.

Lets you customize each sub-field's type, required-ness, default,
position, options, and UI without re-declaring the entire embedded
shape. Sub-fields not explicitly declared are auto-detected when the
parent field has `auto_fields true`.

## Example

    field :items, :nested do
      nested_field :name, :text do
        required true

        ui do
          label "Item name"
          placeholder "e.g. Widget"
        end
      end

      nested_field :count, :number do
        position :last

        ui do
          label "Quantity"
        end
      end
    end

See `MishkaGervaz.Form.Entities.Field` for the parent field,
`MishkaGervaz.Form.Dsl.Fields` for the surrounding DSL, and
`MishkaGervaz.Form.Entities.NestedField.Ui` for the `ui` sub-entity.

# `position`

```elixir
@type position() :: integer() | :first | :last | {:before, atom()} | {:after, atom()}
```

# `t`

```elixir
@type t() :: %MishkaGervaz.Form.Entities.NestedField{
  __identifier__: term(),
  __spark_metadata__: map() | nil,
  default: any(),
  name: atom(),
  options: list() | nil,
  position: position() | nil,
  readonly: boolean(),
  required: boolean() | nil,
  type: atom() | nil,
  ui: MishkaGervaz.Form.Entities.NestedField.Ui.t() | nil,
  visible: boolean()
}
```

# `transform`

---

*Consult [api-reference.md](api-reference.md) for complete listing*