The server may set this response header to emit events with the
requested fragment update.
The header value is a JSON array.
Each element in the array is a JSON object representing an event to be emitted
on the document.
The object property { "type" } defines the event's type. Other properties become properties of the emitted
event object.
Important
HTTP headers may only contain US-ASCII (7-bit) characters.
If you have higher code points in a JSON value, you may
encode those characters using Unicode escape sequences.
Example
Content-Type: text/html
X-Up-Events: [{ "type": "user:created", "id": 5012 }, { "type": "signup:completed" }]
...
<html>
...
</html>
Emitting an event on a layer
Instead of emitting an event on the document, the server may also choose to
emit the event on the layer being updated. To do so, add a property
{ "layer": "current" } to the JSON object of an event:
Content-Type: text/html
X-Up-Events: [{ "type": "user:created", "name:" "foobar", "layer": "current" }]
...
<html>
...
</html>
