The WebTransportDatagramsWritable interface of the WebTransport API is a specialized WritableStream that can be used to write outgoing datagrams to a WebTransport connection.

WebTransportDatagramsWritable is a transferable object.

Instance properties

Also inherits properties from its parent interface, WritableStream.

WebTransportDatagramsWritable.sendGroup

Gets or sets a WebTransportSendGroup that the stream's datagrams are grouped under for the purposes of sendOrder prioritization.

WebTransportDatagramsWritable.sendOrder

Gets or sets an integer indicating the priority of this stream relative to other streams and datagrams in the same sendGroup.

Instance methods

Inherits methods from its parent interface, WritableStream.

Description

In addition to the functionality of a standard WritableStream, the WebTransportDatagramsWritable interface provides the sendGroup property that indicates the group of streams and datagrams that this stream belongs to, and the sendOrder property that indicates the relative priority of this stream within that group. Within a group, bytes queued on higher-priority streams and datagrams are sent before any bytes from lower-priority ones. Different groups are expected to be treated as equals for the purposes of bandwidth allocation — though the precise way bandwidth is divided between groups is implementation-defined.

Objects of this type are not constructed directly. Instead, an instance is returned by the createWritable() method of WebTransportDatagramDuplexStream, which can be accessed using the WebTransport.datagrams property.

The transmission is unreliable, meaning that even though you can define the priority order, there is no guarantee that every datagram will be sent, or that they will arrive in any particular order.

Examples

See createWritable() for an example showing how to create a WebTransportDatagramsWritable and use it to write outgoing datagrams.

Specifications

Browser compatibility

See also

• Streams API
• Using WebTransport