Custom field renderers

Custom renderers change native presentation without moving calculations, visibility, requirements, or validation out of form0-core.

Per-form overrides

Pass a renderer map directly to FormRenderer for an isolated form:

Code
import { FormRenderer } from "form0-react-native"
import { PhotoField } from "./photo-field.jsx"

;<FormRenderer schema={schema} renderers={{ PhotoField }} />

A renderer receives the field and its evaluated interaction state:

Code
function PhotoField({ field, value, onChange, readOnly, required, error, inputProps }) {
  // Render application-owned capture, preview, and removal controls.
}

Preserve applicable properties from inputProps, and call onChange with the value shape expected by the schema and submission boundary.

Providers, registries, and global overrides

Use FieldRegistryProvider for a subtree override or createFieldRegistry({ includeDefaults, renderers }) for an explicit registry instance. The module-level registerFieldComponent, unregisterFieldComponent, and resetFieldComponents helpers mutate the shared default registry and are best reserved for bootstrap code or tests.

Only field types declared by form0-core can be registered. A new schema field type must first be defined in Core; a native renderer alone cannot extend the schema contract.