The list of HTTP headers to be used in the HTTP request for sending Google Cloud
Messaging (GCM) notifications.
- <x-sup-gcm-collapsekey> – An arbitrary string (such as "Updates Available") that is used to collapse a
group of like messages when the device is offline, so that only the last
message gets sent to the client.
- <x-sup-gcm-data> – Payload data, expressed as parameters prefixed with data and suffixed as the
key.
- <x-sup-gcm-delaywhileidle> – Optional. Requests that messages not be delivered until the device becomes
active Represented as 1 for true, or any other value
for false. The default value is false.
- <x-sup-gcm-timetolive> – Specifies how long (in seconds) the message should be kept on GCM storage if
the device is offline.
For more information on GCM headers, see http://developer.android.com/guide/google/gcm/gcm.html#send-msg