Flutter - Postcode

The package is on pub.dev:

flutter pub add nipost_postcode_widget

or add it to pubspec.yaml directly:

dependencies:
  nipost_postcode_widget: ^0.1.0

Usage

import 'package:nipost_postcode_widget/nipost_postcode_widget.dart';

final selection = await PostcodeWidget.show(
  context,
  PostcodeWidgetConfig(
    publishableKey: 'nipost_pk_live_…',
    identifierType: IdentifierType.email,
    prefilledIdentifier: 'ada@example.com',
  ),
);

if (selection != null) {
  debugPrint('picked ${selection.formatted}');
}

show() opens the widget as a full-screen modal flow — identity screen (skipped when prefilledIdentifier is set), saved postcodes, and map-based discover — and returns the PostcodeSelection, or null if the user backed out. selection.toJson() produces exactly the wire shape every other SDK delivers.

Configuration

Field	Notes
`publishableKey`	Required. Your `nipost_pk_…` key.
`identifierType`	`IdentifierType.nin` or `IdentifierType.email`.
`prefilledIdentifier`	Shown locked on the identity screen for the user to confirm.
`environment`	`PostcodeEnvironment.production` (default) or `.staging`. Keys are minted per environment — a `nipost_pk_test_…` key only resolves on staging.
`platformBaseUrlOverride`	A host outside the standard environments (local stack, preview deploy). Wins over `environment`.
`theme`	`PostcodeWidgetTheme` overrides for brand colors.

The package depends only on Flutter and dio, holds no global state, and can be instantiated from multiple places in the same app.