MessageEvent<T>
type MessageEvent<T> = object;
A MessageEvent represents a single message along with metadata about the message.
Remember to import MessageEvent from @foxglove/extension
. This is not the same as the DOM MessageEvent class.
Type Parameters
Type Parameter | Default type |
---|---|
T | unknown |
Properties
topic
topic: string;
The topic name this message was received on, i.e. "/some/topic"
schemaName
schemaName: string;
The schema name is an identifier for the schema of the message within the message event.
receiveTime
receiveTime: Time;
The time in nanoseconds this message was received. This may be set by the local system clock or the data source, depending on the data source used and whether time is simulated via a /clock topic or similar mechanism. The timestamp is often nanoseconds since the UNIX epoch, but may be relative to another event such as system boot time or simulation start time depending on the context.
publishTime?
optional publishTime: Time;
The time in nanoseconds this message was originally published. This is only available for some data sources. The timestamp is often nanoseconds since the UNIX epoch, but may be relative to another event such as system boot time or simulation start time depending on the context.
message
message: T;
The deserialized message as a JavaScript object.
sizeInBytes
sizeInBytes: number;
The approximate size of this message event in its deserialized form. This can be useful for statistics tracking and cache eviction.
originalMessageEvent?
optional originalMessageEvent: MessageEvent;
When subscribing to a topic using the convertTo
option, the message event message
contains the converted message and the originalMessageEvent
field contains the original
un-converted message event.