# Mosquitto-PHP

This is an extension to allow using the [Eclipse Mosquitto™ MQTT client library](http://mosquitto.org) with PHP. See the `examples/` directory for usage.

[![Build Status](https://travis-ci.org/mgdm/Mosquitto-PHP.svg?branch=master)](https://travis-ci.org/mgdm/Mosquitto-PHP)

## PHP 7 support

Thanks to [Sara Golemon](https://twitter.com/SaraMG) this extension now supports PHP 7. I would be grateful if anyone using PHP 7 could test it and let me know how it works out.

## Requirements

* PHP 5.3+
* libmosquitto 1.2.x or later
* Linux or Mac OS X. I do not have a Windows machine handy, though patches or
  pull requests are of course very welcome!

## Installation

If you've used a pre-built package to install Mosquitto, you need to make sure you have the development headers installed. On Red Hat-derived systems, this is probably called `libmosquitto-devel`, and on Debian-based systems it will be `libmosquitto-dev`.

You may obtain this package using [PECL](http://pecl.php.net):

````
pecl install Mosquitto-alpha
````

Alternatively, you can use the normal extension build process:

````
phpize
./configure --with-mosquitto=/path/to/libmosquitto
make
make install
````

Then add `extension=mosquitto.so` to your `php.ini`.

The `--with-mosquitto` argument is optional, and only required if your
libmosquitto install cannot be found.

## General operation

The underlying library is based on callbacks and asynchronous operation. As such, you have to call the `loop()` method of the `Client` frequently to permit the library to handle the messages in its queues. Also, you should use the callback functions to ensure that you only attempt to publish after the client has connected, etc. For example, here is how you would correctly publish a QoS=2 message:

```php
<?php

$c = new Mosquitto\Client;
$c->onConnect(function() use ($c) {
    $c->publish('mgdm/test', 'Hello', 2);
});

$c->connect('test.mosquitto.org');

for ($i = 0; $i < 100; $i++) {
    // Loop around to permit the library to do its work
    $c->loop(1);
}

echo "Finished\n";
```

## API Documentation

The classes in this extension are namespaced.

### Class Mosquitto\Client

This is the actual Mosquitto client.

1. [__construct](#__construct) - create a new client
1. [setCredentials](#setcredentials) - set the credentials to use on connection
1. [setTlsCertificates](#settlscertificates) - set the TLS certificate sources
1. [setTlsInsecure](#settlsinsecure) - Set verification of the server hostname
   in TLS certificates
1. [setTlsOptions](#settlsoptions) - Set advanced TLS options
1. [setTlsPSK](#settlspsk) - Configure the client for pre-shared-key based TLS
   support.
1. [setWill](#setwill) - set the client will, to be delivered if disconnected
   uncleanly
1. [clearWill](#clearwill) - clear a previously-set will
1. [setReconnectDelay](#setreconnectdelay) - set the behaviour if disconnected
   uncleanly
1. [connect](#connect) - connect to an MQTT broker
1. [disconnect](#disconnect) - disconnect from an MQTT broker
1. [onConnect](#onconnect) - set the connect callback
1. [onDisconnect](#ondisconnect) - set the disconnect callback
1. [onLog](#onlog) - set the logging callback
1. [onSubscribe](#onsubscribe) - set the subscribe callback
1. [onMessage](#onmessage) - set the callback fired when a message is received
1. [onPublish](#onpublish) - set the callback fired when a message is published
1. [setMaxInFlightMessages](#setmaxinflightmessages) - set the number of QoS
   1 and 2 messages that can be "in flight" at once
1. [setMessageRetry](#setmessageretry) - set the number of seconds to wait
   before retrying messages
1. [publish](#publish) - publish a message to a broker
1. [subscribe](#subscribe) - subscribe to a topic
1. [unsubscribe](#unsubscribe) - unsubscribe from a topic
1. [loop](#loop) - The main network loop
1. [loopForever](#loopforever) - run loop() in an infinite blocking loop

#### __construct

Creates a new Client instance.

| Parameter | Type | Description |
| --- | --- | ---- |
| id | string | Client ID. Optional. If not supplied or NULL, one will be generated at random. |
| clean_session | boolean | Set to true to instruct the broker to clean all messages and subscriptions on disconnect. |

#### setCredentials

Set the username and password to use on connecting to the broker. Must be
called before connect().

| Parameter | Type | Description |
| --- | --- | ---- |
| Username | string | Username to supply to the broker |
| Password | string | Password to supply to the broker |

#### setTlsCertificates

Configure the client for certificate based SSL/TLS support.  Must be called
before connect(). Cannot be used in conjunction with setTlsPSK().

Define the Certificate Authority certificates to be trusted (ie. the server
certificate must be signed with one of these certificates) using cafile.
If the server you are connecting to requires clients to provide a certificate,
define certfile and keyfile with your client certificate and private key.  If
your private key is encrypted, provide the password as the fourth parameter, or
you will have to enter the password at the command line.

| Parameter | Type | Description |
| --- | --- | ---- |
| capath | string | Path to the PEM encoded trusted CA certificate files, or to a directory containing them |
| certfile | string | Path to the PEM encoded certificate file for this client. Optional. |
| keyfile | string | Path to a file containing the PEM encoded private key for this client. Required if certfile is set. |
| password | string | The password for the keyfile, if it is encrypted. If null, the password will be asked for on the command line. | 

#### setTlsInsecure

Configure verification of the server hostname in the server certificate.  If
value is set to true, it is impossible to guarantee that the host you are
connecting to is not impersonating your server. Do not use this function in
a real system. Must be called before connect().

| Parameter | Type | Description |
| --- | --- | ---- |
| value | boolean | If set to false, the default, certificate hostname checking is performed.  If set to true, no hostname checking is performed and the connection is insecure. |

#### setTlsOptions

Set advanced SSL/TLS options.  Must be called before connect().

| Parameter | Type | Description |
| --- | --- | ---- |
| certReqs | int | Whether or not to verify the server. Can be Mosquitto\Client::SSL_VERIFY_NONE, to disable certificate verification, or Mosquitto\Client::SSL_VERIFY_PEER (the default), to verify the server certificate. |
| tlsVersion | string | The TLS version to use. If NULL, a default is used. The default value depends on the version of OpenSSL the library was compiled against. Available options on OpenSSL >= 1.0.1 are 'tlsv1.2', 'tlsv1.1' and 'tlsv1'. |
| cipers | string | A string describing the ciphers available for use. See the `openssl ciphers` tool for more information. If NULL, the default set will be used. |

#### setTlsPSK

Configure the client for pre-shared-key based TLS support.  Must be called before connect(). Cannot be used in conjunction with setTlsCertificates.

| Parameter | Type | Description |
| --- | --- | ---- |
| psk | string | The pre-shared key in hex format with no leading "0x".
| identity | string | The identity of this client. May be used as the username depending on server settings. |
| cipers | string | Optional. A string describing the ciphers available for use. See the `openssl ciphers` tool for more information. If NULL, the default set will be used. |

#### setWill

Set the client "last will and testament", which will be sent on an unclean
disconnection from the broker. Must be called before connect().

| Parameter | Type | Description |
| --- | --- | ---- |
| topic | string | The topic on which to publish the will. |
| payload | string | The data to send. |
| qos | int | Optional. Default 0. Integer 0, 1, or 2 indicating the Quality of Service to be used. |
| retain | boolean | Optional. Default false. If true, the message will be retained. |

#### clearWill

Remove a previously-set will. No parameters.

#### setReconnectDelay

Control the behaviour of the client when it has unexpectedly disconnected in
loopForever.  The default behaviour if this method is not used is to
repeatedly attempt to reconnect with a delay of 1 second until the connection
succeeds.

| Parameter | Type | Description |
| --- | --- | ---- |
| reconnect_delay | int | Set delay between successive reconnection attempts. |
| reconnect_delay | int | Set max delay between successive reconnection attempts when exponential backoff is enabled |
| exponential_backoff | bool | Enable exponential backoff |

#### connect

Connect to an MQTT broker.

| Parameter | Type | Description |
| --- | --- | ---- |
| host | string | Hostname to connect to |
| port | int | Optional. Port number to connect to. Defaults to 1883. |
| keepalive | int | Optional. Number of sections after which the broker should PING the client if no messages have been recieved. |
| interface | string | Optional. The address or hostname of a local interface to bind to for this connection. |

#### disconnect

Disconnect from the broker. No parameters.

#### onConnect

Set the connect callback.  This is called when the broker sends a CONNACK message in response to a connection.

| Parameter | Type | Description |
| --- | --- | ---- |
| callback | callback | The callback |

The callback should take parameters of the form:

| Parameter | Type | Description |
| --- | --- | ---- |
| rc | int | Response code from the broker. |
| message | string | String description of the response code. |

Response codes are as follows:

| Code | Meaning |
| --- | --- |
| 0 | Success |
| 1 | Connection refused (unacceptable protocol version) |
| 2 | Connection refused (identifier rejected) |
| 3 | Connection refused (broker unavailable ) |
| 4-255 | Reserved for future use |

#### onDisconnect

Set the disconnect callback. This is called when the broker has received the
DISCONNECT command and has disconnected the client.

| Parameter | Type | Description |
| --- | --- | ---- |
| callback | callback | The callback |

The callback should take parameters of the form:

| Parameter | Type | Description |
| --- | --- | ---- |
| rc | int | Reason for the disconnection. 0 means the client requested it. Any other value indicates an unexpected disconnection. |

#### onLog

Set the logging callback.

| Parameter | Type | Description |
| --- | --- | ---- |
| callback | callback | The callback |

The callback should take parameters of the form:

| Parameter | Type | Description |
| --- | --- | ---- |
| level | int | The log message level from the values below |
| str | string | The message string.

The level can be one of:

* Mosquitto\Client::LOG_DEBUG
* Mosquitto\Client::LOG_INFO
* Mosquitto\Client::LOG_NOTICE
* Mosquitto\Client::LOG_WARNING
* Mosquitto\Client::LOG_ERR

#### onSubscribe

Set the subscribe callback.  This is called when the broker responds to
a subscription request.

| Parameter | Type | Description |
| --- | --- | ---- |
| callback | callback | The callback |

The callback should take parameters of the form:

| Parameter | Type | Description |
| --- | --- | ---- |
| mid | int | Message ID of the subscribe message |
| qos_count | int | Number of granted subscriptions |

This function needs to return the granted QoS for each subscription, but
currently cannot.

#### onUnsubscribe

Set the unsubscribe callback.  This is called when the broker responds to
a unsubscribe request.

| Parameter | Type | Description |
| --- | --- | ---- |
| callback | callback | The callback |

The callback should take parameters of the form:

| Parameter | Type | Description |
| --- | --- | ---- |
| mid | int | Message ID of the unsubscribe message |

#### onMessage

Set the message callback.  This is called when a message is received from the broker.

| Parameter | Type | Description |
| --- | --- | ---- |
| callback | callback | The callback |

The callback should take parameters of the form:

| Parameter | Type | Description |
| --- | --- | ---- |
| message | Mosquitto\Message | A Message object containing the message data |


#### onPublish

Set the publish callback, This is called when a message is publish by the client itself.

**Warning**: this may be called before the method `Mosquitto\Client::publish` return the
message id, so, you need to create a queue to deal with the mid list

| Parameter | Type | Description |
| --- | --- | --- |
| callback | callback | The callback |

The callback should take parameters of the form:

| Parameter | Type | Description |
| --- | --- | --- |
| mid | int | the message id returned by `Mosquitto\Client::publish` |


#### setMaxInFlightMessages

Set the number of QoS 1 and 2 messages that can be “in flight” at one time.  An
in flight message is part way through its delivery flow.  Attempts to send
further messages with publish() will result in the messages being queued until
the number of in flight messages reduces.

Set to 0 for no maximum.

| Parameter | Type | Description |
| --- | --- | ---- |
| max_inflight_messages | int | The maximum |

#### setMessageRetry

Set the number of seconds to wait before retrying messages.  This applies to
publish messages with QoS>0.  May be called at any time.

| Parameter | Type | Description |
| --- | --- | ---- |
| message_retry | int | The retry period |

#### publish

Publish a message on a given topic.

| Parameter | Type | Description |
| --- | --- | ---- |
| topic | string | The topic to publish on |
| payload | string | The message payload |
| qos | int | Integer value 0, 1 or 2 indicating the QoS for this message |
| retain | boolean | If true, make this message retained |

return `int` the message id in broker system
**Warning** the message id is not unique

#### subscribe

Subscribe to a topic.

| Parameter | Type | Description |
| --- | --- | ---- |
| topic | string | The topic. |
| qos | The QoS to request for this subscription |

Returns the message ID of the subscription message, so this can be matched up
in the onSubscribe callback.

#### unsubscribe

Unsubscribe from a topic.

| Parameter | Type | Description |
| --- | --- | ---- |
| topic | string | The topic. |
| qos | The QoS to request for this subscription |

Returns the message ID of the subscription message, so this can be matched up
in the onUnsubscribe callback.

#### loop

The main network loop for the client.  You must call this frequently in order
to keep communications between the client and broker working.  If incoming data
is present it will then be processed.  Outgoing commands, from e.g.  publish(),
are normally sent immediately that their function is called, but this is not
always possible. loop() will also attempt to send any remaining outgoing
messages, which also includes commands that are part of the flow for messages
with QoS>0.

| Parameter | Type | Description |
| --- | --- | ---- |
| timeout | int | Optional. Number of milliseconds to wait for network activity. Pass 0 for instant timeout. Defaults to 1000. |
| max_packets | int | Currently unused. |

#### loopForever

Call loop() in an infinite blocking loop. Callbacks will be called as required.
This will handle reconnecting if the connection is lost. Call disconnect() in
a callback to return from the loop.

Note: exceptions thrown in callbacks do not currently cause the loop to exit. To work around this, use loop() and wrap your own loop structure around it such as a while().

| Parameter | Type | Description |
| --- | --- | ---- |
| timeout | int | Optional. Number of milliseconds to wait for network activity. Pass 0 for instant timeout. Defaults to 1000. |
| max_packets | int | Currently unused. |

### Class Mosquitto\Message

Represents a message received from a broker. All data is represented as
properties.

| Property | Type | Description |
| --- | --- | --- |
| topic | string | The topic this message was delivered to. |
| payload | string | The payload of this message. |
| mid | int | The ID of this message. |
| qos | int | The QoS value applied to this message. |
| retain | bool | Whether this is a retained message or not. |

This class has two static methods.

#### topicMatchesSub

Returns true if the supplied topic matches the supplied description, and
otherwise false.

| Parameter | Type | Description |
| --- | --- | ---- |
| topic | string | The topic to match |
| subscription | string | The subscription to match |

#### tokeniseTopic

Tokenise a topic or subscription string into an array of strings representing the topic hierarchy.

| Parameter | Type | Description |
| --- | --- | ---- |
| topic | string | The topic to tokenise |

### Class Mosquitto\Exception

This is an exception that may be thrown by many of the operations in the Client
object.

## To do

* Arginfo
* Logging callbacks
* TLS support
* Tests