Some mobile apps might only be notified on actual chat messages with
a body, so don't let mod_push_keepalive reset the stream management
timeout on other types of traffic.
Add 'include_sender' and 'include_body' options. If one or both of them
are set to 'true', a urn:xmpp:push:summary form with the enabled
field(s) is included in push notifications that are generated for
messages with a body.
The 'include_body' option can instead be set to a static text. In this
case, the specified text will be included in place of the actual message
body. This can be useful to signal the push service whether the
notification was triggered by a message with body (as opposed to other
types of traffic) without leaking actual message contents.
The callback is supposed to provide known options and their default
values, as long as the documentation. Passing default values into
get_mod functions is now deprecated: all defaults should be provided
by the Mod:mod_options/1 callback.
This module tries to keep pending stream management sessions of push
clients alive (as long as the disconnected clients are reachable via
push notifications).