overrideWithValue method

Override overrideWithValue(String value)

Overrides a provider with a value, ejecting the default behavior.

This will also disable the auto-scoping mechanism, meaning that if the overridden provider specified dependencies, it will have no effect.

The main difference between overrideWith and overrideWithValue is:

• overrideWith allows you to replace the implementation of a provider. This gives full access to Ref, and the result will be cached by Riverpod. The override can never change.
• overrideWithValue allows you to replace the result of a provider. If the overridden value ever changes, notifiers will be updated.

Alongside the typical use-cases of overrideWith, overrideWithValue has is particularly useful for converting BuildContext values to providers.

For example, we can make a provider that represents ThemeData from Flutter:

final themeProvider = Provider<ThemeData>((ref) => throw UnimplementedError());

We can then override this provider with the current theme of the app:

MaterialApp(
  builder: (context, child) {
    final theme = Theme.of(context);

    return ProviderScope(
      overrides: [
        /// We override "themeProvider" with a valid theme instance.
        /// This allows providers such as "tagThemeProvider" to read the
        /// current theme, without having a BuildContext.
        themeProvider.overrideWithValue(theme),
      ],
      child: MyApp(),
    );
  },
);

The benefit of using overrideWithValue over overrideWith in this scenario is that if the theme ever changes, then themeProvider will be updated.

Implementation

Override overrideWithValue(String value) {
  return $ProviderOverride(
    origin: this,
    providerOverride: $SyncValueProvider<String>(value),
  );
}