Presence API for PubNub Node.js SDK

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 hereNow() function in your application.

Method(s)

To call Here Now you can use the following method(s) in the Node.js V4 SDK:

1. hereNow( {Array channels, Array channelGroups, Boolean includeUUIDs, Boolean includeState}, Function callback )
   

   Parameter	Type	Required	Defaults	Description
   Operation Arguments	Hash	Yes		A hash of arguments.
   channels	Array	Optional		Specifies the channel name to return occupancy results. If channel is not provided, hereNow() will return data for all channels.
   channelGroups	Array	Optional		The channel group for which here now information should be received.
   includeUUIDs	Boolean	Optional	true	Setting uuid to false disables the return of uuids.
   includeState	Boolean	Optional	false	Setting state to true enables the return of subscriber state information.
   callback	Function	Optional		Executes on a successful/unsuccessful hereNow.

Basic Usage

Get a list of UUIDs subscribed to channel:

pubnub.hereNow(
    {
        channels: ["ch1"],
        channelGroups : ["cg1"],
        includeUUIDs: true,
        includeState: true
    },
    function (status, response) {
        // handle status, response
    }
);

Response

type HereNowResponse = {
    channels: Array<string>,
}

Other Examples

1. Returning State: Requires Presence add-onRequires 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-

   pubnub.hereNow(
       {
           channels: ["my_channel"],
           includeState: true
       },
       function (status, response) {
           // handle status, response
       }
   );
   

   Example Response:

   // Example of Status
   {
       "error": false,
       "operation": "PNHereNowOperation",
       "statusCode": 200
   }
   
   // Example of Response
   {
       "totalChannels": 1,
       "totalOccupancy": 3,
       "channels": {
           "my_channel": {
               "occupants": [
                   {
                       "uuid": "User 1"
                   },
                   {
                       "state": {
                           "age": 18
                       },
                       "uuid": "User 2"
                   },
                   {
                       "state": {
                           "age": 24
                       },
                       "uuid": "User 3"
                   }
               ],
               "name": "my_channel",
               "occupancy": 3
           }
       }
   }
   

2. Return Occupancy Only: Requires Presence add-onRequires 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:

   pubnub.hereNow(
       {
           channels: ["my_channel"],
           includeUUIDs: false
       },
       function (status, response) {
           // handle status, response
       }
   );
   

   Example Response:

   // Example of Status
   {
       "error": false,
       "operation": "PNHereNowOperation",
       "statusCode": 200
   }
   
   // Example of Response
   {
       "totalChannels": 1,
       "totalOccupancy": 3,
       "channels": {
           "my_channel": {
               "occupants": [],
               "name": "my_channel",
               "occupancy": 3
           }
       }
   }
   

3. Channel Group Usage : Requires Presence add-onRequires 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-

   pubnub.hereNow(
       {
           channelGroups : ["my_channel_group"]
       },
       function (status, response) {
           // handle status, response
       }
   );
   

   Example Response:

   // Example of Status
   {
       "error": false,
       "operation": "PNHereNowOperation",
       "statusCode": 200
   }
   
   // Example of Response
   {
       "totalChannels": 2,
       "totalOccupancy": 3,
       "channels": {
           "my_channel_1": {
               "occupants": [
                   {
                       "state": null,
                       "uuid": "User1"
                   },
                   {
                       "state": null,
                       "uuid": "User3"
                   }
               ],
               "name": "my_channel_1",
               "occupancy": 2
           },
           "my_channel_2": {
               "occupants": [
                   {
                       "state": null,
                       "uuid": "User2"
                   }
               ],
               "name": "my_channel_2",
               "occupancy": 1
           }
       }
   }
   

4. Basic usage using Promises Requires Presence add-onRequires 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-

   pubnub.hereNow({
       channels: ["ch1"],
       channelGroups : ["cg1"],
       includeUUIDs: true,
       includeState: true
   }).then((response) => {
       console.log(response)
   }).catch((error) => {
       console.log(error)
   });
   

5. Returning State using Promises: Requires Presence add-onRequires 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-

   pubnub.hereNow({
       channels: ["my_channel"],
       includeState: true
   }).then((response) => {
       console.log(response)
   }).catch((error) => {
       console.log(error)
   });
   

6. Return Occupancy Only using Promises: Requires Presence add-onRequires 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:

   pubnub.hereNow({
       channels: ["my_channel"],
       includeUUIDs: false
   }).then((response) => {
       console.log(response)
   }).catch((error) => {
       console.log(error)
   });
   

7. Channel Group Usage using Promises: 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-

   pubnub.hereNow({
       channelGroups : ["my_channel_group"]
   }).then((response) => {
       console.log(response)
   }).catch((error) => {
       console.log(error)
   });
   

Where 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 list of channels to which a UUID is subscribed to by calling the whereNow 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 whereNow you can use the following method(s) in the Node.js V4 SDK:

1. whereNow ({String uuid},Function callback)
   

   Parameter	Type	Required	Defaults	Description
   Operation Arguments	Hash	Yes		A hash of arguments.
   uuid	String	Optional	current uuid	Specifies the uuid to return channel list for.
   callback	Function	Optional		Executes on a successful/unsuccessful whereNow.

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:

pubnub.whereNow(
    {
        uuid: "uuid"
    },
    function (status, response) {
        // handle status, response
    }
);

Response

// Example of Status
{
    error: false,
    operation: "PNWhereNowOperation",
    statusCode: 200
}

// Example of Response
{
    "channels": ["ch1", "ch2"]
}

Other Examples

1. Basic usage using Promises

   pubnub.whereNow({
       uuid: "uuid"
   }).then((response) => {
       console.log(response);
   }).catch((error) => {
       console.log(error);
   });
   

User State

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

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.

Method(s)

Set State :

1. setState({Array channels, Array channelGroups, Object state},Function callback)
   

   Parameter	Type	Required	Description
   Operation Arguments	Hash	Yes	A hash of arguments.
   channels	Array	Optional	Either channels or channelGroups should be provided, Specifies the channels to set the state.
   channelGroups	Array	Optional	Either channels or channelGroups should be provided, Specifies the Channel Group to set the state
   state	Object	Optional	JSON object of key/value pairs with supported data-types of int, float and string. Nesting of key/values is not permitted and key names beginning with prefix pn are reserved. If the state parameter is undefined, the current state for the specified uuid will be returned. If a specified key already exists for the uuid it will be over-written with the new value. Key values can be deleted by setting the particular value to null.
   callback	Function	Optional	Executes on a successful/unsuccessful setState.

Get State :

1. getState({String uuid, Arraychannels, ArraychannelGroups},Function callback)
   

   Parameter	Type	Required	Defaults	Description
   Operation Arguments	Hash	Yes		A hash of arguments.
   uuid	String	Optional	current uuid	The subscriber uuid to get the current state.
   channels	Array	Optional		Either channels or channelGroups should be provided, Specifies the channels to get the state.
   channelGroups	Array	Optional		Either channels or channelGroups should be provided, Specifies the Channel Group to get the state.
   callback	Function	Optional		Executes on a successful/unsuccessful getState.

Basic Usage

Set State :

pubnub.setState(
    {
        state: newState,
        channels: ['ch1'],
        channelGroups: ['cg1']
    },
    function (status, response) {
        // handle status, response
    }
);

Get State :

pubnub.getState(
    {
        uuid: "uuid",
        channels: ['ch1'],
        channelGroups: ['cg1']
    },
    function (status, response) {
        // handle status, response
    }
);

Response

Set State :

// Example of Status
{
    error: false,
    operation: "PNSetStateOperation",
    statusCode: 200
}

// Example of Response
{
    state: {
        me: 'typing'
    }
}

Get State :

// Example of Status
{
    error: false,
    operation: "PNGetStateOperation",
    statusCode: 200
}

// Example of Response
{
    channels: {
        ch1: {
            me: 'typing'
        }
    }
}

Other Examples

1. Set State Basic usage using Promises

   pubnub.setState({
       state: newState,
       channels: ['ch1'],
       channelGroups: ['cg1']
   }).then((response) => {
       console.log(response)
   }).catch((error) => {
       console.log(error)
   });
   

2. Get State Basic usage using Promises

   pubnub.getState({
       uuid: "uuid",
       channels: ['ch1'],
       channelGroups: ['cg1']
   }).then((response) => {
       console.log(response)
   }).catch((error) => {
       console.log(error)
   });