subscribe method

Future<void> subscribe({ required Client client, required MCPUIRuntime runtime, required String uri, String? binding, String? ownerKey, })

FR-RES-001~003

Implementation

Future<void> subscribe({
  required Client client,
  required MCPUIRuntime runtime,
  required String uri,
  String? binding,
  String? ownerKey,
}) async {
  _logger.debug('Subscribing resource',
      {'uri': uri, 'binding': binding, 'ownerKey': ownerKey});
  try {
    await client.subscribeResource(uri);
  } catch (e, st) {
    _logger.logError('subscribeResource failed', e, st, {'uri': uri});
    throw ResourceSubscriptionException(uri, cause: e);
  }

  if (ownerKey != null) {
    _active.putIfAbsent(ownerKey, () => <String>{}).add(uri);
  }

  if (binding != null) {
    runtime.registerResourceSubscription(uri, binding);
    _logger.debug('Registered binding',
        {'uri': uri, 'binding': binding});
  }

  // Initial read (FR-RES-003) — failures are logged but not propagated.
  try {
    final resource = await client.readResource(uri);
    if (resource.contents.isEmpty) return;
    final text = resource.contents.first.text;
    if (text == null) return;
    final decoded = jsonDecode(text);
    if (decoded is Map<String, dynamic>) {
      decoded.forEach((key, value) {
        runtime.stateManager.set(key, value);
      });
    }
  } catch (e) {
    _logger.warn('Initial resource read failed', {'uri': uri}, e);
  }
}