Publish/Subscribe API for PHP SDK

PubNub delivers messages worldwide in less than 30 ms. Send a message to one recipient or broadcast to thousands of subscribers.

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. PubNub replicates the message across its points of presence and delivers it to all subscribed clients on that 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();
* required
ParameterDescription
channel *
Type: String
Default:
n/a
Destination of message (channel ID).
message *
Type: String|Array
Default:
n/a
The payload.
shouldStore
Type: Boolean
Default:
account default
Store in history.
ttl
Type: Number
Default:
n/a
Set 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 unless you have message retention set to Unlimited on your keyset configuration in the Admin Portal.
  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.
meta
Type: Array
Default:
null
Meta data object which can be used with the filtering ability.
usePost
Type: Boolean
Default:
false
Use POST to publish.
customMessageType
Type: string
Default:
n/a
A 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.

Sample code​

Publish a message to a channel​

Reference code
This example is a self-contained code snippet ready to be run. It includes necessary imports and executes methods with console logging. Use it as a reference when working with other examples in this document.

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()
Integer
An integer representation of the timetoken when the message was published.

Other examples​

Publish with metadata​


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 sends a message to Functions event handlers and Illuminate. The message goes directly to handlers registered on the target channel and triggers their execution. The handler can read the request body. Messages sent via fire() aren't replicated to subscribers and aren't 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();
* required
ParameterDescription
channel *
Type: String
Default:
n/a
Destination of message (channel ID).
message *
Type: String|Array
Default:
n/a
The payload.
meta
Type: Array
Default:
null
Meta data object which can be used with the filtering ability.
usePost
Type: Boolean
Default:
false
Use POST to publish.

Sample code​

Fire a message to a channel​


Signal​

The signal() function sends a signal 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();
* required
ParameterDescription
channel *
Type: String
The channel ID to send the signal to.
message *
Type: String|Array
The signal message payload.

Sample code​

Send a signal to a channel​


Response​

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

Property NameTypeDescription
getTimetoken()
int
An 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 ID. To subscribe to a channel ID 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();
* required
ParameterDescription
channels
Type: String or Array
Subscribe to channels, Either channel ID or channel_group is required.
channelGroups
Type: String or Array
Subscribe to channel_groups, Either channel ID or channel_group is required.
withTimetoken
Type: Integer
Pass a timetoken.
withPresence
Type: Boolean
Also subscribe to related presence information.

For information on how to receive presence events and what those events are, refer to Presence Events.

Sample code​

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()
PNStatusCategory
See the PHP SDK status categories.
isError()
bool
This is true if an error occurred in the execution of the operation.
getException()
PubNubException
Error data of the exception (if Error is true).
getStatusCode()
int
Status code of the execution.
Operation
OperationType
Operation type of the request.

PNMessageResult:

MethodDescription
getMessage()
Type: Object
The message sent on the channel ID.
getSubscription()
Type: String
The channel ID on which the message was received.
getTimetoken()
Type: Integer
Timetoken for the message.

PNPresenceEventResult:

MethodDescription
getStatusCode()
Type: Integer
Events like join, leave, timeout, state-change.
getUuid()
Type: String
uuid for event.
getTimestamp()
Type: Integer
timestamp for event.
getOccupancy()
Type: Integer
Current occupancy.
getSubscription()
Type: String
Message has been received on the channel ID.
getTimetoken()
Type: Integer
timetoken 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 information on how to receive presence events and what those events are, refer to Presence Events.

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
}
Custom 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.

For information on how to receive presence events and what those events are, refer to Presence Events.

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()
show all 40 lines

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​

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);
* required
ParameterDescription
getChannels
Type: String
Default:
false
The channels to get the here now details.
getChannelGroups
Type: String
Default:
false
The channel groups to get the here now details.
setChannels
Type: Array
Default:
false
Unsubscribe to channels, Either channel ID or channelGroup is required.
setChannelGroups
Type: Array
Default:
false
Unsubscribe to channel groups, Either channel ID or channelGroup is required.

Sample code​

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) {
show all 38 lines

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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