jsonDecodeNullableMap function

Map<String, dynamic>? jsonDecodeNullableMap(dynamic json)

Decodes a JSON string into a non-empty Map<String, dynamic> or null.

Returns null if the input is empty or decodes to an empty map.

final result = jsonDecodeNullableMap('{"key": "value"}');
print(result); // {key: value}

final emptyResult = jsonDecodeNullableMap('{}');
print(emptyResult); // null

@ai Use when you need to distinguish between empty and non-empty maps. Handle errors externally.

Implementation

Map<String, dynamic>? jsonDecodeNullableMap(final dynamic json) {
  if (json case final Map<String, dynamic> map) return map.isEmpty ? null : map;
  final jsonString = jsonDecodeString(json);
  if (jsonString.isEmpty) return null;
  return switch (jsonDecode(jsonString)) {
    final Map<String, dynamic> map => map.isEmpty ? null : map,
    _ => null,
  };
}