/// <summary>
/// Copies a <see cref="CloudEvent"/> into an <see cref="HttpResponse" />.
/// </summary>
/// <param name="cloudEvent">The CloudEvent to copy. Must not be null, and must be a valid CloudEvent.</param>
/// <param name="destination">The response to copy the CloudEvent to. Must not be null.</param>
/// <param name="contentMode">Content mode (structured or binary)</param>
/// <param name="formatter">The formatter to use within the conversion. Must not be null.</param>
/// <returns>A task representing the asynchronous operation.</returns>
public static async Task CopyToHttpResponseAsync(this CloudEvent cloudEvent, HttpResponse destination,
ContentMode contentMode, CloudEventFormatter formatter)
{
Validation.CheckCloudEventArgument(cloudEvent, nameof(cloudEvent));
Validation.CheckNotNull(destination, nameof(destination));
Validation.CheckNotNull(formatter, nameof(formatter));
ReadOnlyMemory <byte> content;
ContentType? contentType;
switch (contentMode)
{
case ContentMode.Structured:
content = formatter.EncodeStructuredModeMessage(cloudEvent, out contentType);
break;
case ContentMode.Binary:
content = formatter.EncodeBinaryModeEventData(cloudEvent);
contentType = MimeUtilities.CreateContentTypeOrNull(formatter.GetOrInferDataContentType(cloudEvent));
break;
default:
throw new ArgumentOutOfRangeException(nameof(contentMode), $"Unsupported content mode: {contentMode}");
}
if (contentType is object)
{
destination.ContentType = contentType.ToString();
}
else if (content.Length != 0)
{
throw new ArgumentException("The 'datacontenttype' attribute value must be specified", nameof(cloudEvent));
}
// Map headers in either mode.
// Including the headers in structured mode is optional in the spec (as they're already within the body) but
// can be useful.
destination.Headers.Add(HttpUtilities.SpecVersionHttpHeader, HttpUtilities.EncodeHeaderValue(cloudEvent.SpecVersion.VersionId));
foreach (var attributeAndValue in cloudEvent.GetPopulatedAttributes())
{
var attribute = attributeAndValue.Key;
var value = attributeAndValue.Value;
// The content type is already handled based on the content mode.
if (attribute != cloudEvent.SpecVersion.DataContentTypeAttribute)
{
string headerValue = HttpUtilities.EncodeHeaderValue(attribute.Format(value));
destination.Headers.Add(HttpUtilities.HttpHeaderPrefix + attribute.Name, headerValue);
}
}
destination.ContentLength = content.Length;
await BinaryDataUtilities.CopyToStreamAsync(content, destination.Body).ConfigureAwait(false);
}
/// <summary>
/// Copies a <see cref="CloudEvent"/> batch into the specified <see cref="HttpWebRequest"/>.
/// </summary>
/// <param name="cloudEvents">CloudEvent batch to copy. Must not be null, and must be a valid CloudEvent.</param>
/// <param name="destination">The request to populate. Must not be null.</param>
/// <param name="formatter">The formatter to use within the conversion. Must not be null.</param>
/// <returns>A task representing the asynchronous operation.</returns>
public static async Task CopyToHttpWebRequestAsync(this IReadOnlyList <CloudEvent> cloudEvents,
HttpWebRequest destination,
CloudEventFormatter formatter)
{
Validation.CheckCloudEventBatchArgument(cloudEvents, nameof(cloudEvents));
Validation.CheckNotNull(destination, nameof(destination));
Validation.CheckNotNull(formatter, nameof(formatter));
ReadOnlyMemory <byte> content = formatter.EncodeBatchModeMessage(cloudEvents, out var contentType);
destination.ContentType = contentType.ToString();
await BinaryDataUtilities.CopyToStreamAsync(content, destination.GetRequestStream()).ConfigureAwait(false);
}
/// <summary>
/// Copies a <see cref="CloudEvent"/> batch into an <see cref="HttpListenerResponse" />.
/// </summary>
/// <param name="cloudEvents">The CloudEvent batch to copy. Must not be null, and must be a valid CloudEvent.</param>
/// <param name="destination">The response to copy the CloudEvent to. Must not be null.</param>
/// <param name="formatter">The formatter to use within the conversion. Must not be null.</param>
/// <returns>A task representing the asynchronous operation.</returns>
public static async Task CopyToHttpListenerResponseAsync(this IReadOnlyList <CloudEvent> cloudEvents,
HttpListenerResponse destination, CloudEventFormatter formatter)
{
Validation.CheckCloudEventBatchArgument(cloudEvents, nameof(cloudEvents));
Validation.CheckNotNull(destination, nameof(destination));
Validation.CheckNotNull(formatter, nameof(formatter));
// TODO: Validate that all events in the batch have the same version?
// See https://github.com/cloudevents/spec/issues/807
ReadOnlyMemory <byte> content = formatter.EncodeBatchModeMessage(cloudEvents, out var contentType);
destination.ContentType = contentType.ToString();
await BinaryDataUtilities.CopyToStreamAsync(content, destination.OutputStream).ConfigureAwait(false);
}
