writeValue method

@protected void writeValue(String fieldName, dynamic value, { bool? ignoreNull, bool? exportIfChanged, dynamic convertion(dynamic value)?, })

This method is used to save the values in a Map (JSON), this will be used when the class is being exported to a JSON,

To do this, you must enter the fieldName parameter with the name of the Map key, and in the value parameter the value that will be recorded in Map.

If it is necessary to convert the exported value to another format, inform the convertion parameter the conversion method, this method will receive the current value of the property, and may return the value as needed.

It will also be possible to indicate whether null values should be ignored using the ignoreNull parameter.

Use this method inside the writeValues method that you will override to define how the output JSON will be formed.

Implementation

@protected
void writeValue(String fieldName, dynamic value,
    {bool? ignoreNull,
    bool? exportIfChanged,
    dynamic Function(dynamic value)? convertion}) {
  ignoreNull ??= _ignoreNulls;
  if (ignoreNull && value == null) {
    return;
  }

  if (value is List && convertion != null) {
    value = value.map((item) => convertion(item)).toList();
  } else {
    value = (convertion != null ? convertion(value) : value);
  }

  exportIfChanged ??= _exportOnlyChanged;
  if (exportIfChanged && _originalMap[fieldName] == value) {
    return;
  }

  _lastWritedMap[fieldName] = _convertValueToJson(value);
}