/// <summary>
/// Gets the data (payload) of the <see cref="CloudEvent"/> as type <typeparamref name=
/// "T"/>.
/// <para>
/// This method, along with the <see cref="GetData"/> method, is <em>idempotent</em>. In
/// other words, every call to either of these methods with <em>same instance</em> of <see
/// cref="CloudEvent"/> and the <em>same type</em> <typeparamref name="T"/> will return the
/// <em>same instance</em> of type <typeparamref name="T"/>.
/// </para>
/// <para>
/// If the data object of this cloud event was set using the <see cref=
/// "SetData{TCloudEvent, T}(TCloudEvent, T, DataSerialization)"/> method, then the same
/// instance of <typeparamref name="T"/> that was passed to that method will be returned by
/// this method. Otherwise, the value of <see cref="CloudEvent.StringData"/> is used to
/// deserialize the instance of <typeparamref name="T"/>.
/// </para>
/// </summary>
/// <typeparam name="T">The type of the <see cref="CloudEvent"/> data.</typeparam>
/// <param name="cloudEvent">The <see cref="CloudEvent"/> to get data from.</param>
/// <param name="data">
/// When this method returns, the data of the <paramref name="cloudEvent"/> if it exists
/// as (or can be serialized to) type <typeparamref name="T"/>; otherwise, <see langword=
/// "null"/>. This parameter is passed uninitialized.
/// </param>
/// <param name="serialization">
/// If <paramref name="cloudEvent"/> does not already has a data object associated with it,
/// the kind of serialization that will be used to convert its <see cref=
/// "CloudEvent.StringData"/> to type <typeparamref name="T"/>.
/// </param>
/// <returns>
/// <see langword="true"/> if the data of the <paramref name="cloudEvent"/> exists as (or
/// can be serialized to) type <typeparamref name="T"/>; otherwise <see langword="false"/>.
/// </returns>
/// <exception cref="ArgumentNullException">
/// If <paramref name="cloudEvent"/> is <see langword="null"/>.
/// </exception>
/// <exception cref="ArgumentOutOfRangeException">
/// If <paramref name="serialization"/> is not defined.
/// </exception>
public static bool TryGetData <T>(this CloudEvent cloudEvent, out T data,
DataSerialization serialization = DataSerialization.Json)
where T : class
{
if (cloudEvent is null)
{
throw new ArgumentNullException(nameof(cloudEvent));
}
if (!Enum.IsDefined(typeof(DataSerialization), serialization))
{
throw new ArgumentOutOfRangeException(nameof(serialization));
}
try
{
var dataObject = cloudEvent.GetDataObject <T>(serialization);
if (dataObject is T)
{
data = (T)dataObject;
return(true);
}
}
catch { }
data = default;
return(false);
}
/// <summary>
/// Gets the data (payload) of the <see cref="CloudEvent"/> as type <typeparamref name=
/// "T"/>.
/// <para>
/// This method, along with the <see cref="TryGetData"/> method, is <em>idempotent</em>. In
/// other words, every call to either of these methods with <em>same instance</em> of <see
/// cref="CloudEvent"/> and the <em>same type</em> <typeparamref name="T"/> will return the
/// <em>same instance</em> of type <typeparamref name="T"/>.
/// </para>
/// <para>
/// If the data object of this cloud event was set using the <see cref=
/// "SetData{TCloudEvent, T}(TCloudEvent, T, DataSerialization)"/> method, then the same
/// instance of <typeparamref name="T"/> that was passed to that method will be returned by
/// this method. Otherwise, the value of <see cref="CloudEvent.StringData"/> is used to
/// deserialize the instance of <typeparamref name="T"/>.
/// </para>
/// </summary>
/// <typeparam name="T">The type of the <see cref="CloudEvent"/> data.</typeparam>
/// <param name="cloudEvent">The <see cref="CloudEvent"/> to get data from.</param>
/// <param name="serialization">
/// If <paramref name="cloudEvent"/> does not already has a data object associated with it,
/// the kind of serialization that will be used to convert its <see cref=
/// "CloudEvent.StringData"/> to type <typeparamref name="T"/>.
/// </param>
/// <returns>
/// The data of the <see cref="CloudEvent"/> as type <typeparamref name="T"/>.
/// </returns>
/// <exception cref="ArgumentNullException">
/// If <paramref name="cloudEvent"/> is <see langword="null"/>.
/// </exception>
/// <exception cref="ArgumentOutOfRangeException">
/// If <paramref name="serialization"/> is not defined.
/// </exception>
/// <exception cref="InvalidCastException">
/// If <paramref name="cloudEvent"/> already has a data object associated with it, but that
/// data object cannot be converted to type <typeparamref name="T"/>.
/// </exception>
/// <exception cref="JsonException">
/// If an error occurs during JSON deserialization.
/// </exception>
/// <exception cref="InvalidOperationException">
/// If an error occurs during XML deserialization.
/// </exception>
public static T GetData <T>(this CloudEvent cloudEvent,
DataSerialization serialization = DataSerialization.Json)
where T : class
{
if (cloudEvent is null)
{
throw new ArgumentNullException(nameof(cloudEvent));
}
if (!Enum.IsDefined(typeof(DataSerialization), serialization))
{
throw new ArgumentOutOfRangeException(nameof(serialization));
}
var dataObject = cloudEvent.GetDataObject <T>(serialization);
if (dataObject is T data)
{
return(data);
}
throw new InvalidCastException(
$"Unable to cast the CloudEvent's data of type '{dataObject.GetType().FullName}' to type '{typeof(T).FullName}'.");
}
