maybeFromDynamic static method

JsonWidgetData? maybeFromDynamic(dynamic map, { JsonWidgetRegistry? registry, })

Decodes a JSON object into a dynamic widget. The structure is the same for all dynamic widgets with the exception of the args value. The args depends on the specific type.

{ "type":

Implementation

static JsonWidgetData? maybeFromDynamic(
  dynamic map, {
  JsonWidgetRegistry? registry,
}) {
  JsonWidgetData? result;
  registry ??= JsonWidgetRegistry.instance;

  if (map is JsonWidgetData) {
    result = map;
  } else if (map != null) {
    try {
      final type = map['type'];
      final timer = ExecutionWatch(
        group: 'JsonWidgetData.fromDynamic',
        name: type,
        precision: TimerPrecision.microsecond,
      ).start();
      try {
        if (type is! String) {
          throw HandledJsonWidgetException(
            'Unknown type encountered: [$type]',
            data: map,
          );
        }
        final builder = registry.getWidgetBuilder(type);
        final args = map['args'] as Map? ?? const {};
        final jsonWidgetListenVariables = _getListenVariables(map);

        // The validation needs to happen before we process the dynamic args
        // orelse there may be non-JSON compatible objects in the map which
        // will always fail validation.
        if (kDebugMode) {
          registry.validateBuilderSchema(
            type: type,
            value: args,
            validate: map.containsKey('args') ? true : false,
          );
        }

        result = JsonWidgetData(
          jsonWidgetArgs: map['args'] ?? {},
          jsonWidgetBuilder: () {
            return builder(
              args,
              registry: registry,
            );
          },
          jsonWidgetListenVariables: jsonWidgetListenVariables,
          jsonWidgetId: map['id'],
          jsonWidgetRegistry: registry,
          jsonWidgetType: type,
        );
      } finally {
        timer.stop();
      }
    } catch (e, stack) {
      if (e is HandledJsonWidgetException) {
        rethrow;
      }
      var errorValue = map;
      if (errorValue is Map || errorValue is List) {
        errorValue = const JsonEncoder.withIndent('  ').convert(errorValue);
      }
      if (e is AssertionError) {
        throw HandledJsonWidgetException(
          e,
          data: errorValue,
        );
      } else {
        _logger.severe(
          '''
*** WIDGET PARSE ERROR ***
$errorValue
''',
          e,
          stack,
        );
      }
      throw HandledJsonWidgetException(
        e,
        data: errorValue,
        stackTrace: stack,
      );
    }
  }

  return result;
}