Publish/Subscribe API for PubNub PHP SDK

The foundation of the PubNub service is the ability to send a message and have it delivered anywhere in less than 30ms. Send a message to just one other person, or broadcast to thousands of subscribers at once.

For higher-level conceptual details on publishing and subscribing, refer to Connection Management and to Publish Messages.

Publish​

publish() sends a message to all channel subscribers. A successfully published message is replicated across PubNub's points of presence and sent simultaneously to all subscribed clients on a channel.

  • You must initialize PubNub with the publishKey.
  • You don't have to be subscribed to a channel to publish to it.
  • You cannot publish to multiple channels simultaneously.

Method(s)​

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

$pubnub->publish()
    ->channel(string)
    ->message(string|array)
    ->shouldStore(boolean)
    ->ttl($ttl)
    ->meta(array)
    ->usePost(boolean)
    ->customMessageType(string)
    ->sync();
ParameterTypeRequiredDefaultDescription
channelStringYesn/aDestination of message.
messageString|ArrayYesn/aThe payload.
shouldStoreBooleanOptionalaccount defaultStore in history.
ttlNumberOptionaln/aSet a per message time to live in Message Persistence.
  1. If shouldStore = true, and ttl = 0, the message is stored with no expiry time.
  2. If shouldStore = true and ttl = X (X is an Integer value), the message is stored with an expiry time of X hours.
  3. If shouldStore = false, the ttl parameter is ignored.
  4. If ttl is not specified, then expiration of the message defaults back to the expiry value for the key.
metaArrayOptionalnullMeta data object which can be used with the filtering ability.
usePostBooleanOptionalfalseUse POST to publish.
customMessageTypestringOptionalA case-sensitive, alphanumeric string from 3 to 50 characters describing the business-specific label or category of the message. Dashes - and underscores _ are allowed. The value cannot start with special characters or the string pn_ or pn-.

Examples: text, action, poll.

Basic Usage​

Publish a message to a channel​

$result = $pubnub->publish()
    ->channel("my_channel")
    ->message(["hello", "there"])
    ->shouldStore(true)
    ->ttl(15)
    ->usePost(true)
    ->customMessageType("file-message")
    ->sync();
Subscribe to the channel

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​

The publish() operation returns a PNPublishResult which contains the following fields:

Property NameTypeDescription
getTimetoken()IntegerAn integer representation of the timetoken when the message was published.

Other Examples​

Publish with metadata​

$result = $pubnub->publish()
                ->channel("my_channel")
                ->message(["hello", "there"])
                ->meta(["name" => "Alex"])
                ->sync();

Publish Array​

use PubNub\Exceptions\PubNubException;

try {
    $result = $pubnub->publish()
                    ->channel("my_channel")
                    ->message(["hello", "there"])
                    ->meta(["name" => "Alex", "online" => true])
                    ->sync();
    print_r($result->getTimetoken());
} catch (PubNubException $error) {
    handleException($error);
}

Fire​

The fire endpoint allows the client to send a message to Functions Event Handlers and Illuminate. 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 PHP SDK:

$pubnub->fire()
    ->channel(string)
    ->message(string|array)
    ->meta(array)
    ->usePost(boolean)
    ->sync();
ParameterTypeRequiredDefaultDescription
channelStringYesDestination of message.
messageString|ArrayYesThe payload.
metaArrayOptionalnullMeta data object which can be used with the filtering ability.
usePostBooleanOptionalfalseUse POST to publish.

Basic Usage​

Fire a message to a channel​

use PubNub\Exceptions\PubNubException;

try {
$result = $pubnub->fire()
        ->channel("my_channel")
        ->message(["hello","there"])
        ->usePost(true)
        ->sync();

    echo "Publish worked! Timetoken: " . $result->getTimetoken();
}
catch(\PubNub\Exceptions\PubNubServerException $e) {
    echo "Error happened while publishing: " . $e->getMessage();
}

Signal​

The signal() function is used to send a signal

Signal

A non-persistent message limited to 64 bytes designed for high-volume usecases where the the most recent data is relevant, like GPS location updates.
to all subscribers of a channel.

  • You must initialize PubNub with the publishKey.
  • The message payload size (without the URI or headers) is limited to 64 bytes. If you require a larger payload size, contact support.

Method(s)​

To Send a signal you can use the following method(s) in the PHP SDK:

$pubnub->signal()
    ->channel(string)
    ->message(string|array)
    ->sync();
ParameterTypeRequiredDescription
channelStringYesThe channel to send the signal to.
messageString|ArrayYesThe signal message payload.

Basic Usage​

Send a signal to a channel​

$result = $pubnub->signal()
    ->channel("my_channel")
    ->message("typing...")
    ->sync();
print_r($result->getTimetoken());

Response​

The signal() operation returns a PNSignalResult which contains the following fields:

Property NameTypeDescription
getTimetoken()intAn int representation of the timetoken when the signal was sent.

Subscribe​

Receive messages​

Your app receives messages and events via event listeners. The event listener is a single point through which your app receives all the messages, signals, and events that are sent in any channel you are subscribed to.

For more information about adding a listener, refer to the Event Listeners section.

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.

Subscribe call is blocking and it will block until:
  • A message is published on the channel(s) it is subscribed to (message callback).
  • A presence event is received on the channel(s) it is subscribed to (presence callabck).
  • A status event is triggered by SDK (status callback).

Inside of all of the callbacks above you can throw PubNubUnsubscribeException to exit the subscribe loop.

Unsubscribing from all channels

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 PHP SDK:

$pubnub->subscribe()
    ->channels(string|array)
    ->channelGroups(string|array)
    ->withTimetoken(integer)
    ->withPresence(boolean)
    ->execute();
ParameterTypeRequiredDescription
channelsString or ArrayOptionalSubscribe to channels, Either channel or channel_group is required.
channelGroupsString or ArrayOptionalSubscribe to channel_groups, Either channel or channel_group is required.
withTimetokenIntegerOptionalPass a timetoken.
withPresenceBooleanOptionalAlso subscribe to related presence information.

Basic Usage​

Subscribe to a channel:

$pubnub->subscribe()
    ->channels("my_channel")
    ->execute();
Event listeners

The response of the call is handled by adding a Listener. Please see the Listeners section for more details. Listeners should be added before calling the method.

Response​

PNStatus:

Property NameTypeDescription
getCategory()PNStatusCategoryDetails of StatusCategory are here
isError()boolThis is true if an error occurred in the execution of the operation.
getException()PubNubExceptionError data of the exception (if Error is true).
getStatusCode()intStatus code of the execution.
OperationOperationTypeOperation type of the request.

PNMessageResult:

MethodTypeDescription
getMessage()ObjectThe message sent on channel.
getSubscription()StringThe channel on which the message was received.
getTimetoken()IntegerTimetoken for the message.

PNPresenceEventResult:

MethodTypeDescription
getStatusCode()IntegerEvents like join, leave, timeout, state-change.
getUuid()Stringuuid for event.
getTimestamp()Integertimestamp for event.
getOccupancy()IntegerCurrent occupancy.
getSubscription()StringMessage has been received on channel.
getTimetoken()Integertimetoken of the message.

Other Examples​

Basic subscribe with logging​

use Monolog\Handler\ErrorLogHandler;
use PubNub\PNConfiguration;
use PubNub\PubNub;

$pnconf = new PNConfiguration();

$pnconf->setPublishKey("demo");
$pnconf->setSubscribeKey("demo");

$pubnub = new PubNub($pnconf);

$pubnub->getLogger()->pushHandler(new ErrorLogHandler());

$pubnub->subscribe()->channels("my_channel")->execute();

Subscribing to multiple channels​

It's possible to subscribe to more than one channel using the Multiplexing feature. The example shows how to do that using an array to specify the channel names.

Alternative subscription methods

You can also use Wildcard Subscribe and Channel Groups to subscribe to multiple channels at a time. To use these features, the Stream Controller add-on must be enabled on your keyset in the Admin Portal.

$pubnub->subscribe()
    ->channels(["my_channel1", "my_channel2"])
    ->execute();

Subscribing to a Presence channel​

Requires Presence

This method requires that the Presence add-on is enabled for your key in the Admin Portal.

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->subscribe()
    ->channels("my_channel")
    ->withPresence()
    ->execute();

Sample Responses​

Join Event​
{
    "action": "join",
    "timestamp": 1345546797,
    "uuid": "175c2c67-b2a9-470d-8f4b-1db94f90e39e",
    "occupancy": 2
}
Leave Event​
{
    "action" : "leave",
    "timestamp" : 1345549797,
    "uuid" : "175c2c67-b2a9-470d-8f4b-1db94f90e39e",
    "occupancy" : 1
}
Timeout Event​
{
    "action": "timeout",
    "timestamp": 1345549797,
    "uuid": "76c2c571-9a2b-d074-b4f8-e93e09f49bd",
    "occupancy": 0
}
ustom Presence Event (State Change)​
{
    "action": "state-change",
    "uuid": "76c2c571-9a2b-d074-b4f8-e93e09f49bd",
    "timestamp": 1345549797,
    "data": {
        "isTyping": true
    }
}
Interval Event​
{
    "action":"interval",
    "timestamp":1474396578,
    "occupancy":2
}

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",
    "occupancy" : <# users in channel>,
    "timestamp" : <unix timestamp>,
    "joined" : ["uuid2", "uuid3"],
    "timedout" : ["uuid1"]
}

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.

{
    "action" : "interval",
    "occupancy" : <# users in channel>,
    "timestamp" : <unix timestamp>,
    "here_now_refresh" : true
}

Wildcard subscribe to channels​

Requires Stream Controller add-on

This method requires that the Stream Controller add-on is enabled for your key in the Admin Portal (with Enable Wildcard Subscribe checked). Read the support page on enabling add-on features on your 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 (.).

$pubnub->subscribe()
    ->channels("foo.*")
    ->execute();
Wildcard grants and revokes

Only one level (a.*) of wildcarding is supported. If you grant on * or a.b.*, the grant will treat * or a.b.* as a single channel named either * or a.b.*. You can also revoke permissions from multiple channels using wildcards but only if you previously granted permissions using the same wildcards. Wildcard revokes, similarly to grants, only work one level deep, like a.*.

Subscribing with State​

Requires Presence

This method requires that the Presence add-on is enabled for your key in the Admin Portal.

Required UUID

Always set the UUID to uniquely identify the user or device that connects to PubNub. This UUID should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UUID, you won't be able to connect to PubNub.

use PubNub\PubNub;
use PubNub\PNConfiguration;
use PubNub\Callbacks\SubscribeCallback;

$pnconf = new PNConfiguration();

$pnconf->setPublishKey("demo");
$pnconf->setSubscribeKey("demo");

$pubnub = new PubNub($pnconf);

class MySubscribeCallback extends SubscribeCallback {
    function status($pubnub, $status) {
        if ($status->getCategory() === PNStatusCategory::PNConnectedCategory) {
            $result = $pubnub->setState()
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Subscribe to a channel group​

Requires Stream Controller add-on

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

$pubnub->subscribe()
    ->channelGroups(["cg1", "cg2"])
    ->execute();

Subscribe to the presence channel of a channel group​

note
Requires Stream Controller and Presence add-ons

This method requires both the Stream Controller and Presence add-ons are enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

$pubnub->subscribe()
    ->channelGroups("awesome_channel_group")
    ->withPresence()
    ->execute();

Unsubscribe​

To unsubscribe you should throw PubNubUnsubscribeException somewhere inside status/message/presence callbacks of your subscribe listeners. You should specify channel and / or channel group names to unsubscribe and keep a subscription loop running if some other channels left. Otherwise the exception will unsubscribe from all channels and channel-groups.

Method(s)​

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

(new PubNubUnsubscribeException())
    ->setChannels(array)
    ->setChannelGroups(array);
ParameterTypeRequiredDefaultDescription
getChannelsStringOptionalfalseThe channels to get the here now details.
getChannelGroupsStringOptionalfalseThe channel groups to get the here now details.
setChannelsArrayOptionalfalseUnsubscribe to channels, Either channel or channelGroup is required.
setChannelGroupsArrayOptionalfalseUnsubscribe to channel groups, Either channel or channelGroup is required.

Basic Usage​

Unsubscribe from a channel:

use PubNub\Callbacks\SubscribeCallback;
use PubNub\Enums\PNStatusCategory;
use PubNub\PNConfiguration;
use PubNub\PubNub;
use PubNub\Exceptions\PubNubUnsubscribeException;

$pnconfig = new PNConfiguration();

$pnconfig->setPublishKey("demo");
$pnconfig->setSubscribeKey("demo");

$pubnub = new PubNub($pnconfig);

class MySubscribeCallback extends SubscribeCallback {
    function status($pubnub, $status) {
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Rest Response from Server​

The output below demonstrates the response to a successful call:

{
    "action" : "leave"
}

Other Examples​

Unsubscribing from multiple channels​

Requires Stream Controller add-on

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

use PubNub\Callbacks\SubscribeCallback;
use PubNub\Exceptions\PubNubUnsubscribeException;

class MySubscribeCallback extends SubscribeCallback {
    function status($pubnub, $status) {
        throw new PubNubUnsubscribeException();
    }

    function message($pubnub, $message) {
    }

    function presence($pubnub, $presence) {
    }
}
Example Response​
{
    "action" : "leave"
}

Unsubscribe from a channel group​

use PubNub\Callbacks\SubscribeCallback;
use PubNub\Exceptions\PubNubUnsubscribeException;

class MySubscribeCallback extends SubscribeCallback {
    function status($pubnub, $status) {
        throw (new PubNubUnsubscribeException())->setChannelGroups(["my_channel"]);
    }

    function message($pubnub, $message) {
    }

    function presence($pubnub, $presence) {
    }
}
Example Response​
{
    "action": "leave"
}
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