Presence API for PubNub Python-Twisted SDK

Deprecated

NOTICE: Based on current web trends and our own usage data, PubNub's Python Twisted SDK is deprecated as of May 1, 2019. Deprecation means we will no longer be updating the Python Twisted SDK but will continue to support users currently using it. Please feel free to use our other Python SDK offerings as they will continue to be supported and maintained. If you would like to use the Python Twisted SDK specifically, we would love to work with you on keeping this project alive!

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

This method requires that the Presence add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your 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.

Cache

This method has a 3 second response cache time.

Method(s)

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

pubnub.here_now().channels(String|List|Tuple).channel_groups(String|List|Tuple).include_state(Boolean).include_uuids(Boolean)
ParameterTypeRequiredDefaultDescription
channelsString | List | TupleOptionalThe channels to get the here now details.
channel_groupsString | List | TupleOptionalThe channel groups to get the here now details.
include_stateBooleanOptionalFalseIf True, the response will include the presence states of the users for channels/channelGroups.
include_uuidsBooleanOptionalTrueIf 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("my_channel", "demo")\
.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)
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Returns

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

FieldTypeDescription
total_channelsIntTotal channels.
total_occupancyIntTotal occupancy
channelsDictA dict with values of PNHereNowChannelData for each channel. See PNHereNowChannelData for more details.

PNHereNowChannelData

FieldTypeDescription
channel_nameStringchannel name.
occupancyIntoccupancy of the channel.
occupantsListA list of PNHereNowOccupantData, see PNHereNowOccupantData for more details.

PNHereNowOccupantData

FieldTypeDescription
uuidStringuuid of the user.
stateDictstate of the user.

Other Examples

Returning State

Requires Presence add-on

This method requires that the Presence add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

d = pubnub.here_now().channels("my_channel").\
include_uuids(True).include_state(True).deferred()

d.addCallback(my_callback)
Example Response
{
total_channels: 1,
channels: [{
channel_name: "my_channel",
occupancy: 1,
occupants: [{
uuid: "myUuid1"
state: {
"abcd": {
"age": 15
}
}
}]
}],
total_occupancy: 1
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Return Occupancy Only

Requires Presence add-on

This method requires that the Presence add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

You can return only the occupancy information for a single channel by specifying the channel and setting UUIDs to false:

d = pubnub.here_now().channels("my_channel").\
include_uuids(False).include_state(False).deferred()

d.addCallback(my_callback)
Example Response
{
total_channels: 1,
channels: [{
channel_name: "my_channel",
occupancy: 3,
occupants: []
}],
total_occupancy: 3
}

Here Now for Channel Groups

d = pubnub.here_now().channel_groups(['cg1', 'cg2', 'cg3']).\
include_uuids(True).include_state(True).deferred()

d.addCallback(my_callback)
Example Response
{
total_channels: 1,
channels: [
{
channel_name: "my_channel",
occupancy: 1,
occupants: [{
uuid: "143r34f34t34fq34q34q3",
state: None
}]
},
{
occupancy: 1,
occupants: [{
uuid: "123123234t234f34fq3dq",
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Where Now

Requires Presence add-on

This method requires that the Presence add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

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-Twisted SDK:

pubnub.where_now().uuid(String)
ParameterTypeRequiredDescription
uuidStringOptionaluuid 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

# if we're using inlineCallbacks
envelope = yield pubnub.where_now().deferred()

# if we're not using inlineCallbacks
d = pubnub.where_now().deferred()
d.addCallback(my_callback)

Returns

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

FieldTypeDescription
channelsListThe list of channels where the UUID is present.

Other Examples

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

d = pubnub.where_now().uuid('some-other-uuid').deferred()
d.addCallback(my_callback)

User State

Requires Presence add-on

This method requires that the Presence add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

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)
ParameterTypeRequiredDescription
channelsString | List | TupleOptionalchannels to set state.
channel_groupsString | List | TupleOptionalchannel groups to set state.
stateDictOptionalstate to set.

Get State

pubnub.get_state().channels(String|List|Tuple).channel_groups(String|List|Tuple).uuid(String)
ParameterTypeRequiredDescription
channelsString | List | TupleOptionalchannels to get state.
channel_groupsString | List | TupleOptionalchannel groups to get state.
uuidStringOptionaluuid to get state from.

Basic Usage

Set State

my_state = {
'age': 20
}
d = pubnub.set_state().channels(['ch1', 'ch2', 'ch3']).state(my_state).deferred()
d.addCallback(my_callback)

Get State

d = pubnub.get_state().channels(['ch1', 'ch2', 'ch3']).uuid('such_uuid').deferred()
d.addCallback(my_callback)

Returns

  • The set_state() operation returns a PNSetStateResult which contains the following fields:
FieldTypeDescription
stateDictdict of UUIDs and the user states.
  • The get_state() operation returns a PNGetStateResult which contains the following fields:
FieldTypeDescription
channelsDictdict 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"
}
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