Publish/Subscribe API for PubNub Titanium SDK

Publish

Description

The publish() function is used to send a message to all subscribers of a channel. To publish a message you must first specify a valid publishKey at initialization. A successfully published message is replicated across the PubNub Real-Time Network and sent simultaneously to all subscribed clients on a channel.

Messages in transit can be secured from potential eavesdroppers with SSL/TLS by setting ssl to true during initialization.

Publish Anytime

It's not required to be subscribed to a channel in order to publish to that channel.

Message Data:

The message argument can contain any JSON serializable data, including: Objects, Arrays, Ints and Strings. data should not contain special Titanium V4 classes or functions as these will not serialize. String content can include any single-byte or multi-byte UTF-8 character.

Don't Use JSON.stringify!

It is important to note that you should not use JSON.stringify() when sending signals/messages via PubNub. Why? Because the serialization is done for you automatically. Instead just pass the full object as the message payload. PubNub takes care of everything for you.

Message Size:

The maximum number of characters per message is 32 KiB by default. The maximum message size is based on the final escaped character count, including the channel name. An ideal message size is under 1800 bytes which allows a message to be compressed and sent using single IP datagram (1.5 KiB) providing optimal network performance.

If the message you publish exceeds the configured size, you will receive the following message:

Message Too Large Error

["PUBLISHED",[0,"Message Too Large","13524237335750949"]]

For further details please check: https://support.pubnub.com/hc/en-us/articles/360051495932-Calculating-Message-Payload-Size-Before-Publish

Message Publish Rate:

Messages can be published as fast as bandwidth conditions will allow. There is a soft limit based on max throughput since messages will be discarded if the subscriber can't keep pace with the publisher.

For example, if 200 messages are published simultaneously before a subscriber has had a chance to receive any messages, the subscriber may not receive the first 100 messages because the message queue has a limit of only 100 messages stored in memory.

Publishing to Multiple Channels:

It is not possible to publish a message to multiple channels simultaneously. The message must be published to one channel at a time.

Publishing Messages Reliably:

There are some best practices to ensure messages are delivered when publishing to a channel:

• Publish to any given channel in a serial manner (not concurrently).
• Check that the return code is success (e.g. [1,"Sent","136074940..."])
• Publish the next message only after receiving a success return code.
• If a failure code is returned ([0,"blah","<timetoken>"]), retry the publish.
• Avoid exceeding the in-memory queue's capacity of 100 messages. An overflow situation (aka missed messages) can occur if slow subscribers fail to keep up with the publish pace in a given period of time.
• Throttle publish bursts in accordance with your app's latency needs e.g. Publish no faster than 5 msgs per second to any one channel.

Method(s)

To Publish a message you can use the following method(s) in the Titanium V4 SDK:

1. publish( {Object message, String channel, Boolean storeInHistory, Boolean sendByPost, Object meta, Number ttl }, Function callback )
   

   Parameter	Type	Required	Defaults	Description
   Operation Arguments	Hash	Yes		A hash of arguments.
   message	Object	Yes		The message may be any valid JSON type including objects, arrays, strings, and numbers.
   channel	String	Yes		Specifies channel name to publish messages to.
   storeInHistory	Boolean	Optional	true	If true the messages are stored in history. If storeInHistory is not specified, then the history configuration on the key is used.
   sendByPost	Boolean	Optional	false	When true, the SDK uses HTTP POST to publish the messages. The message is sent in the BODY of the request, instead of the query string when HTTP GET is used. Also the messages are compressed thus reducing the size of the messages. Using HTTP POST to publish messages adheres to RESTful API best practices.
   meta	Object	Optional		Publish extra meta with the request.
   ttl	Number	Optional		Set a per message time to live in storage. If storeInHistory = true, and ttl = 0, the message is stored with no expiry time. If storeInHistory = true and ttl = X (X is an Integer value), the message is stored with an expiry time of X hours. If storeInHistory = false, the ttl parameter is ignored. If ttl is not specified, then expiration of the message defaults back to the expiry value for the key.
   callback	Function	Optional		Executes on a successful/unsuccessful publish.

Basic Usage

Publish a message to a channel:

pubnub.publish(
    {
        message: {
            such: 'object'
        },
        channel: 'my_channel',
        sendByPost: false, // true to send via post
        storeInHistory: false, //override default storage options
        meta: {
            "cool": "meta"
        }   // publish extra meta with the request
    },
    function (status, response) {
        if (status.error) {
            // handle error
            console.log(status)
        } else {
            console.log("message Published w/ timetoken", response.timetoken)
        }
    }
);

Note

Before running the above publish example, either using the Debug Console or in a separate script running in a separate terminal window, subscribe to the same channel that is being published to.

Response

type PublishResponse = {
    timetoken: number
}

Other Examples

1. Publish a JSON serialized message

   var newMessage = {
       text: 'Hi There!'
   }
   pubnub.publish(
       {
           message: newMessage,
           channel: 'my_channel'
       },
       function(status, response) {
           if (status.error) {
               console.log("publishing failed w/ status: ", status);
           } else {
               console.log("message published w/ server response: ", response);
           }
       }
   );
   

2. Store the published message for 10 hours

   pubnub.publish(
       {
           message: {
               such: 'Hello from the PubNub Angular2 SDK!'
           },
           channel: 'my_channel',
           storeInHistory: true,
           ttl: 10
       },
       function (status, response) {
           if (status.error) {
               console.log(status);
           } else {
               console.log("message Published w/ timetoken", response.timetoken);
           }
       }
   );
   

3. Basic usage using Promises

   pubnub.publish({
       message:{
           such: 'Hello from the PubNub Angular2 SDK!'
       },
       channel: 'my_channel'
   }).then((response) => {
       console.log(response)
   }).catch((error) => {
       console.log(error)
   });
   

4. Publish a JSON serialized message using Promises

   var newMessage = {
       text: 'Hi There!'
   }
   pubnub.publish({
       message: newMessage,
       channel: 'my_channel'
   }).then((response) => {
       console.log(response)
   }).catch((error) => {
       console.log(error)
   });
   

5. Store the published message for 10 hours using Promises

   pubnub.publish({
       message: {
           such: 'Hello from the PubNub Angular2 SDK!'
       },
       channel: 'my_channel',
       storeInHistory: true,
       ttl: 10
   }).then((response) => {
       console.log(response)
   }).catch((error) => {
       console.log(error)
   });
   

Fire

Description

The fire endpoint allows the client to send a message to PubNub Functions Event Handlers. These messages will go directly to any Event Handlers registered on the channel that you fire to and will trigger their execution. The content of the fired request will be available for processing within the Event Handler. The message sent via fire() isn't replicated, and so won't be received by any subscribers to the channel. The message is also not stored in history.

Method(s)

To Fire a message you can use the following method(s) in the Titanium V4 SDK:

1. fire( {Object message, String channel, Boolean sendByPost, Object meta}, Function callback )
   

   Parameter	Type	Required	Defaults	Description
   Operation Arguments	Hash	Yes		A hash of arguments.
   message	Object	Yes		The message may be any valid JSON type including objects, arrays, strings, and numbers.
   channel	String	Yes		Specifies channel name to publish messages to.
   sendByPost	Boolean	Optional	false	If true the messages sent via POST.
   meta	Object	Optional		Publish extra meta with the request.
   callback	Function	Optional		Executes on a successful/unsuccessful publish.

Basic Usage

Fire a message to a channel:

pubnub.fire(
    {
        message: {
            such: 'Hello from the PubNub Angular2 SDK!'
        },
        channel: 'my_channel'
    },
    function (status, response) {
        if (status.error) {
            console.log(status);
        } else {
            console.log("message fired w/ timetoken", response.timetoken);
        }
    }
);

Signal

Description

The signal() function is used to send a signal to all subscribers of a channel.

By default, signals are limited to a message payload size of 64 bytes. This limit applies only to the payload, and not to the URI or headers. If you require a larger payload size, please contact support.

Method(s)

To Signal a message you can use the following method(s) in the Titanium V4 SDK:

1. signal( {String message, String channel}, Function callback )
   

   Parameter	Type	Required	Description
   Operation Arguments	Hash	Yes	A hash of arguments.
   message	String	Yes	The message may be any valid JSON type including objects, arrays, strings, and numbers.
   channel	String	Yes	Specifies channel name to send messages to.
   callback	Function	Optional	Executes on a successful/unsuccessful send.

Basic Usage

Signal a message to a channel:

pubnub.signal({
    message: 'hello',
    channel: 'foo',
});

Response

type SignalResponse = {
    timetoken: number
}

Subscribe

Description

This function causes the client to create an open TCP socket to the PubNub Real-Time Network and begin listening for messages on a specified channel. To subscribe to a channel the client must send the appropriate subscribeKey at initialization. By default a newly subscribed client will only receive messages published to the channel after the subscribe() call completes.

Tip

You can be notified of connectivity via the listener, on establishing connection the statusEvent.category returns PNConnectedCategory.

By waiting for the connect event to return before attempting to publish, you can avoid a potential race condition on clients that subscribe and immediately publish messages before the subscribe has completed.

Warning

Unsubscribing from all channels, and then subscribing to a new channel Y is not the same as subscribing to channel Y and then unsubscribing from the previously-subscribed channel(s). Unsubscribing from all channels resets the last-received timetoken and thus, there could be some gaps in the subscription that may lead to message loss.

Method(s)

To Subscribe to a channel you can use the following method(s) in the Titanium V4 SDK:

1. subscribe({Array channels, Array channelGroups, Boolean withPresence, Number timetoken})
   

   Parameter	Type	Required	Defaults	Description
   Operation Arguments	Hash	Yes		A hash of arguments.
   channels	Array	Yes		Specifies the channels to subscribe to. It is possible to specify multiple channels as a list or as an array.
   channelGroups	Array	Specifying either channels or channelGroups is mandatory		Specifies the channelGroups to subscribe to.
   withPresence	Boolean	Optional	false	If true it also subscribes to presence instances.
   timetoken	Number	Optional		Specifies timetoken from which to start returning any available cached messages. Message retrieval with timetoken is not guaranteed and should only be considered a best-effort service.

Basic Usage

Subscribe to a channel:

pubnub.subscribe({
    channels: ['my_channel'],
    withPresence: true
});

Returns

The following objects will be returned in the Status Response

Object	Description
category	PNConnectedCategory
operation	PNSubscribeOperation
affectedChannels	The channels affected in the operation, of type array.
subscribedChannels	All the current subscribed channels, of type array.
affectedChannelGroups	The channel groups affected in the operation, of type array.
lastTimetoken	The last timetoken used in the subscribe request, of type long.
currentTimetoken	The current timetoken fetched in the subscribe response, which is going to be used in the next request, of type long.

{
    category: 'PNConnectedCategory',
    operation: 'PNSubscribeOperation',
    affectedChannels: ['my_channel_1'],
    subscribedChannels: ['my_channel_1'],
    affectedChannelGroups: [],
    lastTimetoken: '14974492380756600',
    currentTimetoken: '14974492384874375'
}

The following objects will be returned in the Subscribe Message Response

Object	Description
channel	The channel for which the message belongs.
subscription	The channel group or wildcard subscription match (if exists).
timetoken	Publish timetoken.
message	The payload.
actualChannel	Deprecated. Use property channel.
subscribedChannel	Deprecated. Use property subscription.

{
    actualChannel: null,
    channel: "my_channel_1",
    message: "Hello World!",
    publisher: "pn-58e1a647-3e8a-4c7f-bfa4-e007ea4b2073",
    subscribedChannel: "my_channel_1",
    subscription: null,
    timetoken: "14966804541029440"
}

The following objects will be returned in the Presence Response

Object	Description
action	Can be join, leave, state-change or timeout.
channel	The channel for which the message belongs.
occupancy	No. of users connected with the channel.
state	User State.
subscription	The channel group or wildcard subscription match (if exists)
timestamp	Current timetoken.
timetoken	Publish timetoken.
uuid	UUIDs of users who are connected with the channel.

{
    category: 'PNConnectedCategory',
    operation: 'PNSubscribeOperation',
    affectedChannels: ['my_channel_1'],
    subscribedChannels: ['my_channel_1'],
    affectedChannelGroups: [],
    lastTimetoken: '14974492380756600',
    currentTimetoken: '14974492384874375'
}

Other Examples

1. Subscribing to more than one channel: Requires Stream Controller add-onRequires that the Stream Controller 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-

   It is possible to subscribe to more than one channel over a single TCP socket by taking advantage of Multiplexing feature. See the Multiplexing section for more info on this feature as well as the examples below using a list or an array to specify channel name.

   Subscribing by specifying channel as an array:

   pubnub.subscribe({
       channels: ['my_channel1', 'my_channel2', 'my_channel3']
   });
   

2. Subscribing to a Presence channel: 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-

   For any given channel there is an associated Presence channel. You can subscribe directly to the channel by appending -pnpres to the channel name. For example the channel named my_channel would have the presence channel named my_channel-pnpres.

   pubnub.addListener({
       presence: function(m) {
           console.log(m);
       },
       message: function(message) {
           console.log(message)
       }
   });
   
   pubnub.subscribe({
       channels: ["my_channel"],
       withPresence: true
   });
   

   Sample Responses

   Join Event

   {
       "channel": "my_channel",
       "subscription": null,
       "actualChannel": null,
       "subscribedChannel": "my_channel-pnpres",
       "action": "join",
       "timetoken": "15119466699655811",
       "occupancy": 2,
       "uuid": "User1",
       "timestamp": 1511946669
   }
   

   Leave Event

   {
       "channel": "my_channel",
       "subscription": null,
       "actualChannel": null,
       "subscribedChannel": "my_channel-pnpres",
       "action": "leave",
       "timetoken": "15119446002445794",
       "occupancy": 1,
       "uuid": "User1",
       "timestamp": 1511944600
   }
   

   Timeout Event

   {
      "channel": "my_channel",
      "subscription": null,
      "actualChannel": null,
      "subscribedChannel": "my_channel-pnpres",
      "action": "timeout",
      "timetoken": "15119519897494311",
      "occupancy": 3,
      "uuid": "User2",
      "timestamp": 1511951989
   }
   

   Custom Presence Event (State Change)

   {
       "channel": "my_channel",
       "subscription": null,
       "actualChannel": null,
       "subscribedChannel": "my_channel-pnpres",
       "action": "state-change",
       "state": {
           "isTyping": true
       },
       "timetoken": "15119477895378127",
       "occupancy": 5,
       "uuid": "User4",
       "timestamp": 1511947789
   }
   

   Interval Event

   {
       "action": "interval",
       "occupancy": 2,
       "timestamp": 1511947739
   }
   

   When a channel is in interval mode with presence_deltas pnconfig flag enabled, the interval message may also include the following fields which contain an array of changed UUIDs since the last interval message.

   • joined
   • left
   • timedout

   For example, this interval message indicates there were 2 new UUIDs that joined and 1 timed out UUID since the last interval:

   {
       "action":"interval",
       "timestamp":1548340678,
       "occupancy":2,
       "join":["pn-94bea6d1-2a9e-48d8-9758-f1b7162631ed","pn-cecbfbe3-312f-4928-93a2-5a79c91b10e0"]},
       "timedout":["pn-cecbfbe3-312f-4928-93a2-5a79c91b10e0"],
       "b":"my-channel-pnpres"
   }
   

   If the full interval message is greater than 30KB (since the max publish payload is ∼32KB), none of the extra fields will be present. Instead there will be a here_now_refresh boolean field set to true. This indicates to the user that they should do a hereNow request to get the complete list of users present in the channel.

   {
       "channel": "my_channel",
       "subscription": null,
       "actualChannel": null,
       "subscribedChannel": "my_channel-pnpres",
       "action": "interval",
       "timetoken": "15119477396210903",
       "occupancy": 4,
       "timestamp": 1511947739,
       "here_now_refresh" : true
   }
   

3. Wildcard subscribe to channels: Requires Stream Controller add-onRequires that the Stream Controller add-on is enabled with Enable Wildcard Subscribe checked 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-

   Wildcard subscribes allow the client to subscribe to multiple channels using wildcard. For example, if you subscribe to a.* you will get all messages for a.b, a.c, a.x. The wildcarded * portion refers to any portion of the channel string name after the dot (.).

   Note

   3 levels (2 dots) of wildcarding is supported, e.g.:
   a.*
   

   a.b.*

   pubnub.subscribe({
       channels: ['ab.*']
   });
   

4. Subscribe to a channel group: Requires Stream Controller add-onRequires that the Stream Controller 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.subscribe({
       channelGroups: ['my_channelGroup']
   });
   

5. Subscribing to more than one channel group: Requires Stream Controller add-onRequires that the Stream Controller 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.subscribe({
       channelGroups: ['my_channelGroup1', 'my_channelGroup2', 'my_channelGroup3']
   });
   

6. Subscribing to a channel and channel group simultaneously: Requires Stream Controller add-onRequires that the Stream Controller 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.subscribe({
       channels: ['my_channel'],
       channelGroups: ['my_channelGroup']
   });
   

Unsubscribe

Description

When subscribed to a single channel, this function causes the client to issue a leave from the channel and close any open socket to the PubNub Network. For multiplexed channels, the specified channel(s) will be removed and the socket remains open until there are no more channels remaining in the list.

Warning

Unsubscribing from all channels, and then subscribing to a new channel Y is not the same as subscribing to channel Y and then unsubscribing from the previously-subscribed channel(s). Unsubscribing from all channels resets the last-received timetoken and thus, there could be some gaps in the subscription that may lead to message loss.

Method(s)

To Unsubscribe from a channel you can use the following method(s) in the Titanium V4 SDK:

1. unsubscribe({Array channels, Array channelGroups})
   

   Parameter	Type	Required	Description
   Operation Arguments	Hash	Yes	A hash of arguments.
   channels	Array	Yes	Specifies the channel to unsubscribe from.
   channelGroups	Array	Specifying either channels or channelGroups is mandatory	Specifies the channelGroups to unsubscribe from.

Basic Usage

Unsubscribe from a channel:

pubnub.unsubscribe({
    channels: ['my_channel']
})

Response

The output below demonstrates the response to a successful call:

{
    "action" : "leave"
}

Other Examples

1. Unsubscribing from multiple channels. Requires Stream Controller add-onRequires that the Stream Controller 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.unsubscribe({
       channels : ['my_channel1', 'my_channel2', 'my_channel3']
   });
   

   Example Response:

   {
       "action" : "leave"
   }
   

2. Unsubscribing from multiple channel groups. Requires Stream Controller add-onRequires that the Stream Controller 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.unsubscribe({
       channelGroups : ['my_channelGroup1', 'my_channelGroup2', 'my_channelGroup3']
   });
   

Unsubscribe All

Description

Unsubscribe from all channels and all channel groups

Method(s)

1. unsubscribeAll()
   

Basic Usage

pubnub.unsubscribeAll();

Returns

None

Listeners

Description

You can be notified of connectivity status, message and presence notifications via the listeners.

Listeners should be added before calling the method.

Adding Listeners

A listener lets you to catch up real time messages, get presence and status information if you do not want to use the getMessage, getPresence, getStatus methods. Remember add a listener before subscribing a channel.

pubnub.addListener({
    message: function(m) {
        // handle message
        var channelName = m.channel; // The channel for which the message belongs
        var channelGroup = m.subscription; // The channel group or wildcard subscription match (if exists)
        var pubTT = m.timetoken; // Publish timetoken
        var msg = m.message; // The Payload
        var publisher = m.publisher; //The Publisher
    },
    presence: function(p) {
        // handle presence
        var action = p.action; // Can be join, leave, state-change or timeout
        var channelName = p.channel; // The channel for which the message belongs
        var occupancy = p.occupancy; // No. of users connected with the channel
        var state = p.state; // User State
        var channelGroup = p.subscription; //  The channel group or wildcard subscription match (if exists)
        var publishTime = p.timestamp; // Publish timetoken
        var timetoken = p.timetoken;  // Current timetoken
        var uuid = p.uuid; // UUIDs of users who are connected with the channel
    },
    signal: function(s) {
        // handle signal
        var channelName = s.channel; // The channel for which the signal belongs
        var channelGroup = s.subscription; // The channel group or wildcard subscription match (if exists)
        var pubTT = s.timetoken; // Publish timetoken
        var msg = s.message; // The Payload
        var publisher = s.publisher; //The Publisher
    },
    status: function(s) {
        var affectedChannelGroups = s.affectedChannelGroups; // The channel groups affected in the operation, of type array.
        var affectedChannels = s.affectedChannels; // The channels affected in the operation, of type array.
        var category = s.category; //Returns PNConnectedCategory
        var operation = s.operation; //Returns PNSubscribeOperation
        var lastTimetoken = s.lastTimetoken; //The last timetoken used in the subscribe request, of type long.
        var currentTimetoken = s.currentTimetoken; //The current timetoken fetched in the subscribe response, which is going to be used in the next request, of type long.
        var subscribedChannels = s.subscribedChannels; //All the current subscribed channels, of type array.
    }
});

Removing Listeners

var existingListener = {
    message: function() {
    }
}

pubnub.removeListener(existingListener);

Listener status events

Category	Description
PNNetworkUpCategory	The SDK detected that the network is online.
PNNetworkDownCategory	The SDK announces this when a connection isn't available, or when the SDK isn't able to reach the PubNub Data Stream Network.
PNNetworkIssuesCategory	A subscribe event experienced an exception when running. The SDK isn't able to reach the PubNub Data Stream Network. This may be due to many reasons, such as: the machine or device isn't connected to the internet; the internet connection has been lost; your internet service provider is having trouble; or, perhaps the SDK is behind a proxy.
PNReconnectedCategory	The SDK was able to reconnect to PubNub.
PNConnectedCategory	SDK subscribed with a new mix of channels. This is fired every time the channel or channel group mix changes.
PNAccessDeniedCategory	PAM permission failure.
PNMalformedResponseCategory	JSON parsing crashed.
PNBadRequestCategory	The server responded with a bad response error because the request is malformed.
PNDecryptionErrorCategory	If using decryption strategies and the decryption fails.
PNTimeoutCategory	Failure to establish a connection to PubNub due to a timeout.
PNRequestMessageCountExceedCategory	The SDK announces this error if requestMessageCountThreshold is set, and the number of messages received from PubNub (in-memory cache messages) exceeds the threshold.
PNUnknownCategory	Returned when the subscriber gets a non-200 HTTP response code from the server.