Presence API for PubNub Python-Tornado SDK

Python version support

Python SDK versions 5.0.0 and higher no longer support Python v2.7 and the Twisted and Tornado frameworks. If you require support for any of these, use SDK version 4.8.1.

Note that PubNub will stop supporting versions of Python lower than 3.7 by the end of 2021.

Presence enables you to track the online and offline status of users and devices in real time, as well as store custom state information. Presence provides authoritative information on:

When a user has joined or left a channel
Who, and how many, users are subscribed to a particular channel
Which channel(s) an individual user is subscribed to
Associated state information for these users

Learn more about our Presence feature here.

Here Now

Requires Presence add-on Requires that the Presence add-on is enabled for your key. See this page on enabling add-on features on your keys:
https://support.pubnub.com/hc/en-us/articles/360051974791-How-do-I-enable-add-on-features-for-my-keys-

Description

You can obtain information about the current state of a channel including a list of unique user-ids currently subscribed to the channel and the total occupancy count of the channel by calling the here_now() function in your application.

Method(s)

To call Here Now you can use the following method(s) in the Python-Tornado SDK:

pubnub.here_now().channels(String|List|Tuple).channel_groups(String|List|Tuple).include_state(Boolean).include_uuids(Boolean)

Parameter	Type	Required	Defaults	Description
`channels`	String \| List \| Tuple	Optional		The `channels` to get the here now details.
`channel_groups`	String \| List \| Tuple	Optional		The `channel groups` to get the here now details.
`include_state`	Boolean	Optional	`False`	If `True`, the response will include the presence states of the users for channels/channelGroups.
`include_uuids`	Boolean	Optional	`True`	If `True`, the response will include the UUIDs of the connected clients.

Basic Usage

Get a list of UUIDs subscribed to channel:

envelope = yield pubnub.here_now()\
    .channels(['cool_channel1', 'cool_channel2'])\
    .include_uuids(True)\
    .future()

if envelope.status.is_error():
    # handle error
    return

for channel_data in envelope.result.channels:
    print("---")
    print("channel: %s" % channel_data.channel_name)
    print("occupancy: %s" % channel_data.occupancy)

    print("occupants: %s" % channel_data.channel_name)
for occupant in channel_data.occupants:
    print("uuid: %s, state: %s" % (occupant.uuid, occupant.state))

Returns

The here_now() operation returns a PNHereNowResult which contains the following fields:

Field	Type	Description
`total_channels`	Int	Total `channels`.
`total_occupancy`	Int	Total `occupancy`
`channels`	Dict	A dict with values of `PNHereNowChannelData` for each channel. See PNHereNowChannelData for more details.

PNHereNowChannelData:

Field	Type	Description
`channel_name`	String	`channel` name.
`occupancy`	Int	`occupancy` of the `channel`.
`occupants`	List	A list of `PNHereNowOccupantData`, see PNHereNowOccupantData for more details.

PNHereNowOccupantData:

Field	Type	Description
`uuid`	String	`uuid` of the user.
`state`	Dict	`state` of the user.

Other Examples

Returning State:

envelope = yield pubnub.here_now().channels("my_channel").\
    include_uuids(True).include_state(True).future()

Example Response:

{
    total_channels: 1,
    channels: [{
        channel_name: "my_channel",
        occupancy: 1,
        occupants: [{
            uuid: "myUuid1"
            state: {
                "abcd": {
                    "age": 15
                }
            }
        }]
    }],
    total_occupancy: 1
}

Return Occupancy Only: Requires Presence add-on Requires that the Presence add-on is enabled for your key. See this page on enabling add-on features on your keys:
https://support.pubnub.com/hc/en-us/articles/360051974791-How-do-I-enable-add-on-features-for-my-keys-

You can return only the occupancy information for a single channel by specifying the channel and setting UUIDs to false:
```
envelope = yield pubnub.here_now().channels("my_channel").\
    include_uuids(False).include_state(False).future()
```
Example Response:
```
{
    total_channels: 1,
    channels: [{
        channel_name: "my_channel",
        occupancy: 3,
        occupants: []
    }],
    total_occupancy: 3
}
```

Here Now for Channel Groups:

envelope = yield pubnub.here_now().channel_groups(['cg1', 'cg2', 'cg3']).\
    include_uuids(True).include_state(True).future()

Example Response:

{
    total_channels: 1,
    channels: [
        {
            channel_name: "my_channel",
            occupancy: 1,
            occupants: [{
                uuid: "143r34f34t34fq34q34q3",
                state: None
            }]
        },
        {
            occupancy: 1,
            occupants: [{
                uuid: "123123234t234f34fq3dq",
                state: None
            }]
        },
        {
            occupancy: 1,
            occupants: [{
                uuid: "23f34d3f4rq34r34rq23q",
                state: None
            }]
        },
        {
            occupancy: 1,
            occupants: [{
                uuid: "w34tcw45t45tcw435tww3",
                state: None
            }]
        }
    ],
    total_occupancy: 4
}

Where Now

Description

You can obtain information about the current list of channels to which a UUID is subscribed to by calling the where_now() function in your application.

Note

If the app is killed/crashes and restarted (or the page containing the PubNub instance is refreshed on the browser) within the heartbeat window no timeout event is generated.

Method(s)

To call where_now() you can use the following method(s) in the Python-Tornado SDK:

```
pubnub.where_now().uuid(String)
```
Parameter Type Required Description

uuid String Optional uuid to get info on.

Parameter	Type	Required	Description
`uuid`	String	Optional	`uuid` to get info on.

Basic Usage

You simply need to define the uuid and the callback function to be used to send the data to as in the example below.

Get a list of channels a UUID is subscribed to:

envelope = yield pubnub.where_now().future()

Returns

The where_now() operation returns a PNWhereNowResult which contains the following fields:

Field	Type	Description
`channels`	List	The list of `channels` where the `UUID` is present.

Other Examples

Obtain information about the current list of channels of some other UUID

envelope = yield pubnub.where_now().uuid('some-other-uuid').future()

User State

Description

The state API is used to set/get key/value pairs specific to a subscriber uuid.

State information is supplied as a JSON object of key/value pairs.

Important

Presence state must be expressed as a dict. When calling set_state, be sure to supply an initialized dict which can be serialized.

Method(s)

Set State:

pubnub.set_state().channels(String|List|Tuple).channel_groups(String|List|Tuple).state(Dict)

Parameter	Type	Required	Description
`channels`	String \| List \| Tuple	Optional	`channels` to set `state`.
`channel_groups`	String \| List \| Tuple	Optional	`channel groups` to set `state`.
`state`	Dict	Optional	`state` to set.

Get State:

pubnub.get_state().channels(String|List|Tuple).channel_groups(String|List|Tuple).uuid(String)

Parameter	Type	Required	Description
`channels`	String \| List \| Tuple	Optional	`channels` to get `state`.
`channel_groups`	String \| List \| Tuple	Optional	`channel groups` to get `state`.
`uuid`	String	Optional	`uuid` to get state on.

Basic Usage

Set State :

my_state = {
    'age': 20
}
envelope = yield pubnub.set_state().channels(['ch1', 'ch2', 'ch3']).state(my_state).future()

Get State :

envelope = yield pubnub.get_state().channels(['ch1', 'ch2', 'ch3']).uuid('such_uuid').future()

Returns

The set_state() operation returns a PNSetStateResult which contains the following fields:

Field	Type	Description
`state`	Dict	dict of UUIDs and the user states.

The get_state() operation returns a PNGetStateResult which contains the following fields:

Field	Type	Description
`channels`	Dict	dict of `channels` and the user states.

Other Examples

Set state for channels in channel group:

my_state = {
    'age': 20
}
envelope = yield pubnub.set_state().channel_groups(['gr1', 'gr2', 'gr3']).state(my_state).future()

The above code would return the following response to the client:

{
    first  : "Robert",
    last   : "Plant",
    age    : 59,
    region : "UK"
}