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up.protocol X-Up-Events
HTTP header

The server may set this response header to emit events with the requested fragment update.

The header value is a relaxed JSON array. Each element in the array is an 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>