requiredValue<T> method

T requiredValue<T>(
  1. String key, {
  2. PayloadCodec<T>? codec,
})

Returns the decoded value for key, throwing when it is missing.

Implementation

T requiredValue<T>(String key, {PayloadCodec<T>? codec}) {
  if (!containsKey(key) || this[key] == null) {
    throw StateError("Missing required payload key '$key'.");
  }
  return value<T>(key, codec: codec) as T;
}