fromJson static method

MetricDescriptor? fromJson(dynamic value)

Returns a new MetricDescriptor instance and imports its values from value if it's a Map, null otherwise.

Implementation

// ignore: prefer_constructors_over_static_methods
static MetricDescriptor? fromJson(dynamic value) {
  if (value is Map) {
    final json = value.cast<String, dynamic>();

    // Ensure that the map contains the required keys.
    // Note 1: the values aren't checked for validity beyond being non-null.
    // Note 2: this code is stripped in release mode!
    assert(() {
      assert(json.containsKey(r'label'),
          'Required key "MetricDescriptor[label]" is missing from JSON.');
      assert(json[r'label'] != null,
          'Required key "MetricDescriptor[label]" has a null value in JSON.');
      return true;
    }());

    return MetricDescriptor(
      description: mapValueOfType<String>(json, r'description'),
      label: mapValueOfType<String>(json, r'label')!,
      unit: mapValueOfType<String>(json, r'unit'),
    );
  }
  return null;
}