PubSub.h File Reference

#include <stdint.h>
#include "commons/Includes.h"

Go to the source code of this file.

Classes
struct	MessageBase
	Structure that contains the fields used by every message. More...
struct	SubscribeAnnouncement
	Structure that contains the fields used by a subscribe message, apart from those inherited from the MessageBase. More...
struct	UnsubscribeAnnouncement
	Structure that contains the fields used by a unsubscribe message, apart from those inherited from the MessageBase. More...
struct	PublishContent
	Structure that contains the fields used by a publish message, apart from those inherited from the MessageBase. More...
struct	PayloadContent
	Structure representing the content of a payload This structure holds properties of the content received inside a publication message. More...

Macros
#define	MAXTOPICLENGTH   24
#define	MAXCONTENTSIZE   30

Enumerations
enum	MessageType { MSGTYPE_SUBSCRIBE = (uint8_t)0x00 , MSGTYPE_UNSUBSCRIBE , MSGTYPE_PUBLISH }
	Enumerates every type of message sent between the broker and the clients. More...

Functions
LMQErrType	publish (uint8_t *mac, char *topic, void *payload, size_t payloadSize, Elog *_logger=disableLogger())
	Publishes a message to the broker.
LMQErrType	subscribe (uint8_t *mac, char *topic, Elog *_logger=disableLogger())
	Subscribes to a topic on the broker.
LMQErrType	unsubscribe (uint8_t *mac, char *topic, Elog *_logger=disableLogger())
	Unsubscribes from a topic on the broker.
bool	isLMQMessage (const uint8_t *incomingData)
	Checks if the data received is a MQ message.
PayloadContent	getLMQPayload (const uint8_t *incomingData)
	Gets the payload content inside a published message This function extracts the payload from the bytes of a received publication message.

Detailed Description

Author

Rubén Gómez Villegas

This file contains the necessary definitions and declarations to publish, subscribe and unsubscribe as a LoboMQ client.

Definition in file PubSub.h.

Macro Definition Documentation

MAXCONTENTSIZE

#define MAXCONTENTSIZE   30

Definition at line 18 of file PubSub.h.

MAXTOPICLENGTH

#define MAXTOPICLENGTH   24

Definition at line 17 of file PubSub.h.

Enumeration Type Documentation

MessageType

enum MessageType

Enumerates every type of message sent between the broker and the clients.

Enumerator
MSGTYPE_SUBSCRIBE	Subscribe message, sent from subscriber to broker.
MSGTYPE_UNSUBSCRIBE	Unsubscribe message, sent from subscriber to broker.
MSGTYPE_PUBLISH	Publish message, sent from publisher to broker or from broker to subscriber.

Definition at line 25 of file PubSub.h.

Function Documentation

getLMQPayload()

PayloadContent getLMQPayload

(

const uint8_t *

incomingData

)

Gets the payload content inside a published message This function extracts the payload from the bytes of a received publication message.

Parameters

incomingData

The data received.

Returns

A PayloadContent structure containing the extracted payload content.

Note

This function is recommended to be used at the subscriber side in the data receive callback alongside isLMQMessage(). Pseudocode example:

OnReceiveCallback(incomingData) {  
    if isLMQMessage(incomingData)  
        payload = getLMQPayload(incomingData)  
} 

Definition at line 191 of file PubSub.cpp.

isLMQMessage()

bool isLMQMessage

(

const uint8_t *

incomingData

)

Checks if the data received is a MQ message.

This function checks if the received bytes represent a MQ message from this library.

Parameters

incomingData

The data received.

Return values

`true`	if the data is a MQ message.
`false`	otherwise.

Note

This function is recommended to be used at the subscriber side in the data receive callback alongside getLMQPayload(). Pseudocode example:

OnReceiveCallback(incomingData) {  
    if isLMQMessage(incomingData)  
        payload = getLMQPayload(incomingData)  
} 

Definition at line 186 of file PubSub.cpp.

publish()

LMQErrType publish	(	uint8_t *	mac,
		char *	topic,
		void *	payload,
		size_t	payloadSize,
		Elog *	_logger = disableLogger() )

Publishes a message to the broker.

This function takes the payload and builds a message that will be published to the specified topic on the broker.

Parameters

mac	The broker MAC address.
topic	The topic to publish the message to. It can't contain wildcard characters (+, #) nor non-UTF-8 characters. Invalid example: +/café. Valid example: kitchen/coffee.
payload	Pointer to the message payload.
payloadSize	Size of the message payload.
_logger	Pointer to the logger object.

Return values

`LMQ_ERR_SUCCESS`	if the message is successfully published.
`LMQ_ERR_BAD_ESP_CONFIG`	if ESP-NOW couldn't be initialized.
`LMQ_ERR_INVAL_TOPIC`	if the given topic is invalid.
`LMQ_ERR_ESP_SEND_FAIL`	if the message couldn't be sent.

Definition at line 105 of file PubSub.cpp.

subscribe()

LMQErrType subscribe	(	uint8_t *	mac,
		char *	topic,
		Elog *	_logger = disableLogger() )

Subscribes to a topic on the broker.

This function sends a message to the broker announcing that the calling board is interested in receiving all the messages compatible with the specified topic.

Parameters

mac	The broker MAC address.
topic	The topic the board subscribes to. Is compatible with wildcard characters (+, #) when used properly, and can't contain non-UTF-8 characters. Invalid example: résumé/+/#/garden. Valid example: +/+/out/#.
_logger	Pointer to the logger object.

Return values

`LMQ_ERR_SUCCESS`	if the message is successfully published.
`LMQ_ERR_BAD_ESP_CONFIG`	if ESP-NOW couldn't be initialized.
`LMQ_ERR_INVAL_TOPIC`	if the given topic is invalid.
`LMQ_ERR_ESP_SEND_FAIL`	if the message couldn't be sent.

Definition at line 133 of file PubSub.cpp.

unsubscribe()

LMQErrType unsubscribe	(	uint8_t *	mac,
		char *	topic,
		Elog *	_logger = disableLogger() )

Unsubscribes from a topic on the broker.

This function sends a message to the broker announcing that the calling board is no longer interested in receiving all the messages compatible with the specified topic.

Parameters

mac	The broker MAC address.
topic	The MQ topic the board unsubscribes from. Is compatible with wildcard characters (+, #) when used properly, and can't contain non-UTF-8 characters. Invalid example: résumé/+/#/garden. Valid example: +/+/out/#.
_logger	Pointer to the logger object.

Return values

`LMQ_ERR_SUCCESS`	if the message is successfully published.
`LMQ_ERR_BAD_ESP_CONFIG`	if ESP-NOW couldn't be initialized.
`LMQ_ERR_INVAL_TOPIC`	if the given topic is invalid.
`LMQ_ERR_ESP_SEND_FAIL`	if the message couldn't be sent.

Definition at line 159 of file PubSub.cpp.