mqtt::subscribe_options Class Reference

#include <subscribe_options.h>

Public Types
enum	RetainHandling { SEND_RETAINED_ON_SUBSCRIBE = 0 , SEND_RETAINED_ON_NEW = 1 , DONT_SEND_RETAINED = 2 }
using	ptr_t = std::shared_ptr<subscribe_options>
using	const_ptr_t = std::shared_ptr<const subscribe_options>

Public Member Functions
	subscribe_options ()
	subscribe_options (bool noLocal, bool retainAsPublished=false, RetainHandling retainHandling=SEND_RETAINED_ON_SUBSCRIBE)
	subscribe_options (MQTTSubscribe_options opts)
bool	get_no_local () const
void	set_no_local (bool on=true)
bool	get_retain_as_published () const
void	set_retain_as_published (bool on=true)
auto	get_retain_handling () const -> RetainHandling
void	set_retain_handling (RetainHandling retainHandling)

Static Public Attributes
static constexpr bool	NO_LOCAL = true
static constexpr bool	LOCAL = false
static constexpr bool	SUBSCRIBE_NO_LOCAL = true
static constexpr bool	SUBSCRIBE_LOCAL = false
static constexpr bool	NO_RETAIN_AS_PUBLISHED = false
static constexpr bool	RETAIN_AS_PUBLISHED = true

Friends
class	async_client
class	response_options

Detailed Description

The MQTT v5 subscription options.

The subscribe options are bitfields in the payload of a SUBSCRIBE packet, forming a single options byte for each topic filter in the subscription.

These were added in MQTT v5. The default (zero/false) value for each field gives the behavior that was present in MQTT v3.1.1. To get a new behavior the field(s) must be set.

These are defined in section 3.8.3.1 of the MQTT v5 spec.

Member Typedef Documentation

ptr_t

using mqtt::subscribe_options::ptr_t = std::shared_ptr<subscribe_options>

Smart/shared pointer to an object of this class.

const_ptr_t

using mqtt::subscribe_options::const_ptr_t = std::shared_ptr<const subscribe_options>

Smart/shared pointer to a const object of this class.

Member Enumeration Documentation

RetainHandling

enum mqtt::subscribe_options::RetainHandling

The options for subscription retain handling

Enumerator
SEND_RETAINED_ON_SUBSCRIBE	Send retained messages at the time of the subscribe
SEND_RETAINED_ON_NEW	Send retained messages on subscribe only if subscription is new
DONT_SEND_RETAINED	Do not send retained messages at all

Constructor & Destructor Documentation

subscribe_options() [1/3]

mqtt::subscribe_options::subscribe_options ( )

inline

Create default subscription options. These are the default options corresponding to the original MQTT (v3) behaviors.

subscribe_options() [2/3]

mqtt::subscribe_options::subscribe_options ( bool noLocal, bool retainAsPublished = false, RetainHandling retainHandling = SEND_RETAINED_ON_SUBSCRIBE )

inlineexplicit

Creates a set of subscription options.

Parameters

noLocal	Whether the server should send back our own publications, if subscribed.
retainAsPublished	Whether to keep the retained flag as in the original published message (true).
retainHandling	When to send retained messages: (SEND_RETAINED_ON_SUBSCRIBE, 0) At the time of the subscribe (SEND_RETAINED_ON_NEW, 1) Only at the time of a new subscribe (DONT_SEND_RETAINED, 2) Not at the time of subscribe

subscribe_options() [3/3]

mqtt::subscribe_options::subscribe_options ( MQTTSubscribe_options opts )

inlineexplicit

Creates the set of subscribe options from an underlying C struct.

Parameters

opts	The Paho C subscribe options

Member Function Documentation

get_no_local()

bool mqtt::subscribe_options::get_no_local ( ) const

inline

Gets the value of the "no local" flag.

Returns

Whether the server should send back our own publications, if subscribed.

set_no_local()

void mqtt::subscribe_options::set_no_local ( bool on = true )

inline

Sets the "no local" flag on or off.

Parameters

on	Whether the server should send back our own publications, if subscribed.

get_retain_as_published()

bool mqtt::subscribe_options::get_retain_as_published ( ) const

inline

Gets the "retain as published" flag.

Returns

Whether to keep the retained flag as in the original published message.

set_retain_as_published()

void mqtt::subscribe_options::set_retain_as_published ( bool on = true )

inline

Sets the "retain as published" flag on or off.

Parameters

on	Whether to keep the retained flag as in the original published message.

get_retain_handling()

auto mqtt::subscribe_options::get_retain_handling ( ) const -> RetainHandling

inline

Gets the "retain handling" option.

Returns

When to send retained messages:

• (SEND_RETAINED_ON_SUBSCRIBE, 0) At the time of the subscribe
• (SEND_RETAINED_ON_NEW, 1) Only at the time of a new subscribe
• (DONT_SEND_RETAINED, 2) Not at the time of subscribe

set_retain_handling()

void mqtt::subscribe_options::set_retain_handling ( RetainHandling retainHandling )

inline

Sets the "retain handling" option.

Parameters

retainHandling

When to send retained messages: (SEND_RETAINED_ON_SUBSCRIBE, 0) At the time of the subscribe (SEND_RETAINED_ON_NEW, 1) Only at the time of a new subscribe (DONT_SEND_RETAINED, 2) Not at the time of subscribe

Friends And Related Symbol Documentation

async_client

friend class async_client

friend

The client and response have special access

response_options

friend class response_options

friend

Field Documentation

NO_LOCAL

bool mqtt::subscribe_options::NO_LOCAL = true

staticconstexpr

Don't receive our own publications

LOCAL

bool mqtt::subscribe_options::LOCAL = false

staticconstexpr

Receive our own publications

SUBSCRIBE_NO_LOCAL

bool mqtt::subscribe_options::SUBSCRIBE_NO_LOCAL = true

staticconstexpr

Deprecated

Don't receive our own publications

SUBSCRIBE_LOCAL

bool mqtt::subscribe_options::SUBSCRIBE_LOCAL = false

staticconstexpr

Deprecated

Receive our own publications (obsolete name)

NO_RETAIN_AS_PUBLISHED

bool mqtt::subscribe_options::NO_RETAIN_AS_PUBLISHED = false

staticconstexpr

Retain flag is only set on publications sent by a broker if in response to a subscribe request

RETAIN_AS_PUBLISHED

bool mqtt::subscribe_options::RETAIN_AS_PUBLISHED = true

staticconstexpr

Keep the retain flag as on the original publish message

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The documentation for this class was generated from the following file:

• subscribe_options.h