NetworkTables Instance. More...

#include <networktables/NetworkTableInstance.h>

Public Types
enum	NetworkMode { kNetModeNone = NT_NET_MODE_NONE , kNetModeServer = NT_NET_MODE_SERVER , kNetModeClient3 = NT_NET_MODE_CLIENT3 , kNetModeClient4 = NT_NET_MODE_CLIENT4 , kNetModeLocal = NT_NET_MODE_LOCAL }
	Client/server mode flag values (as returned by GetNetworkMode()). More...

enum	LogLevel { kLogCritical = NT_LOG_CRITICAL , kLogError = NT_LOG_ERROR , kLogWarning = NT_LOG_WARNING , kLogInfo = NT_LOG_INFO , kLogDebug = NT_LOG_DEBUG , kLogDebug1 = NT_LOG_DEBUG1 , kLogDebug2 = NT_LOG_DEBUG2 , kLogDebug3 = NT_LOG_DEBUG3 , kLogDebug4 = NT_LOG_DEBUG4 }
	Logging levels (as used by SetLogger()). More...

Public Member Functions
	NetworkTableInstance () noexcept
	Construct invalid instance. More...

	NetworkTableInstance (NT_Inst inst) noexcept
	Construct from native handle. More...

	operator bool () const
	Determines if the native handle is valid. More...

NT_Inst	GetHandle () const
	Gets the native handle for the entry. More...

Topic	GetTopic (std::string_view name) const
	Gets a "generic" (untyped) topic. More...

BooleanTopic	GetBooleanTopic (std::string_view name) const
	Gets a boolean topic. More...

IntegerTopic	GetIntegerTopic (std::string_view name) const
	Gets an integer topic. More...

FloatTopic	GetFloatTopic (std::string_view name) const
	Gets a float topic. More...

DoubleTopic	GetDoubleTopic (std::string_view name) const
	Gets a double topic. More...

StringTopic	GetStringTopic (std::string_view name) const
	Gets a string topic. More...

RawTopic	GetRawTopic (std::string_view name) const
	Gets a raw topic. More...

BooleanArrayTopic	GetBooleanArrayTopic (std::string_view name) const
	Gets a boolean array topic. More...

IntegerArrayTopic	GetIntegerArrayTopic (std::string_view name) const
	Gets an integer array topic. More...

FloatArrayTopic	GetFloatArrayTopic (std::string_view name) const
	Gets a float array topic. More...

DoubleArrayTopic	GetDoubleArrayTopic (std::string_view name) const
	Gets a double array topic. More...

StringArrayTopic	GetStringArrayTopic (std::string_view name) const
	Gets a string array topic. More...

template<wpi::ProtobufSerializable T>
ProtobufTopic< T >	GetProtobufTopic (std::string_view name) const
	Gets a protobuf serialized value topic. More...

template<typename T , typename... I> requires wpi::StructSerializable<T, I...>
StructTopic< T, I... >	GetStructTopic (std::string_view name, I... info) const
	Gets a raw struct serialized value topic. More...

template<typename T , typename... I> requires wpi::StructSerializable<T, I...>
StructArrayTopic< T, I... >	GetStructArrayTopic (std::string_view name, I... info) const
	Gets a raw struct serialized array topic. More...

std::vector< Topic >	GetTopics ()
	Get Published Topics. More...

std::vector< Topic >	GetTopics (std::string_view prefix)
	Get Published Topics. More...

std::vector< Topic >	GetTopics (std::string_view prefix, unsigned int types)
	Get Published Topics. More...

std::vector< Topic >	GetTopics (std::string_view prefix, std::span< std::string_view > types)
	Get Published Topics. More...

std::vector< TopicInfo >	GetTopicInfo ()
	Get Topic Information about multiple topics. More...

std::vector< TopicInfo >	GetTopicInfo (std::string_view prefix)
	Get Topic Information about multiple topics. More...

std::vector< TopicInfo >	GetTopicInfo (std::string_view prefix, unsigned int types)
	Get Topic Information about multiple topics. More...

std::vector< TopicInfo >	GetTopicInfo (std::string_view prefix, std::span< std::string_view > types)
	Get Topic Information about multiple topics. More...

NetworkTableEntry	GetEntry (std::string_view name)
	Gets the entry for a key. More...

std::shared_ptr< NetworkTable >	GetTable (std::string_view key) const
	Gets the table with the specified key. More...

Client/Server Functions
unsigned int	GetNetworkMode () const
	Get the current network mode. More...

void	StartLocal ()
	Starts local-only operation. More...

void	StopLocal ()
	Stops local-only operation. More...

void	StartServer (std::string_view persist_filename="networktables.json", const char *listen_address="", unsigned int port3=kDefaultPort3, unsigned int port4=kDefaultPort4)
	Starts a server using the specified filename, listening address, and port. More...

void	StopServer ()
	Stops the server if it is running. More...

void	StartClient3 (std::string_view identity)
	Starts a NT3 client. More...

void	StartClient4 (std::string_view identity)
	Starts a NT4 client. More...

void	StopClient ()
	Stops the client if it is running. More...

void	SetServer (const char *server_name, unsigned int port=0)
	Sets server address and port for client (without restarting client). More...

void	SetServer (std::span< const std::pair< std::string_view, unsigned int > > servers)
	Sets server addresses and ports for client (without restarting client). More...

void	SetServer (std::span< const std::string_view > servers, unsigned int port=0)
	Sets server addresses and port for client (without restarting client). More...

void	SetServerTeam (unsigned int team, unsigned int port=0)
	Sets server addresses and port for client (without restarting client). More...

void	Disconnect ()
	Disconnects the client if it's running and connected. More...

void	StartDSClient (unsigned int port=0)
	Starts requesting server address from Driver Station. More...

void	StopDSClient ()
	Stops requesting server address from Driver Station. More...

void	FlushLocal () const
	Flushes all updated values immediately to the local client/server. More...

void	Flush () const
	Flushes all updated values immediately to the network. More...

std::vector< ConnectionInfo >	GetConnections () const
	Get information on the currently established network connections. More...

bool	IsConnected () const
	Return whether or not the instance is connected to another node. More...

std::optional< int64_t >	GetServerTimeOffset () const
	Get the time offset between server time and local time. More...

Logger Functions
NT_Listener	AddLogger (unsigned int minLevel, unsigned int maxLevel, ListenerCallback func)
	Add logger callback function. More...

Static Public Member Functions
static NetworkTableInstance	GetDefault ()
	Get global default instance. More...

static NetworkTableInstance	Create ()
	Create an instance. More...

static void	Destroy (NetworkTableInstance &inst)
	Destroys an instance (note: this has global effect). More...

Static Public Attributes
static constexpr unsigned int	kDefaultPort3 = NT_DEFAULT_PORT3
	The default port that network tables operates on for NT3. More...

static constexpr unsigned int	kDefaultPort4 = NT_DEFAULT_PORT4
	The default port that network tables operates on for NT4. More...

Schema Functions
bool	HasSchema (std::string_view name) const
	Returns whether there is a data schema already registered with the given name. More...

void	AddSchema (std::string_view name, std::string_view type, std::span< const uint8_t > schema)
	Registers a data schema. More...

void	AddSchema (std::string_view name, std::string_view type, std::string_view schema)
	Registers a data schema. More...

template<wpi::ProtobufSerializable T>
void	AddProtobufSchema (wpi::ProtobufMessage< T > &msg)
	Registers a protobuf schema. More...

template<typename T , typename... I> requires wpi::StructSerializable<T, I...>
void	AddStructSchema (const I &... info)
	Registers a struct schema. More...

bool	operator== (const NetworkTableInstance &) const =default
	Equality operator. More...

Listener Functions
bool	WaitForListenerQueue (double timeout)
	Wait for the listener queue to be empty. More...

NT_Listener	AddConnectionListener (bool immediate_notify, ListenerCallback callback) const
	Add a connection listener. More...

NT_Listener	AddTimeSyncListener (bool immediate_notify, ListenerCallback callback) const
	Add a time synchronization listener. More...

NT_Listener	AddListener (Topic topic, unsigned int eventMask, ListenerCallback listener)
	Add a listener for changes on a particular topic. More...

NT_Listener	AddListener (Subscriber &subscriber, unsigned int eventMask, ListenerCallback listener)
	Add a listener for changes on a subscriber. More...

NT_Listener	AddListener (MultiSubscriber &subscriber, int eventMask, ListenerCallback listener)
	Add a listener for changes on a subscriber. More...

NT_Listener	AddListener (const NetworkTableEntry &entry, int eventMask, ListenerCallback listener)
	Add a listener for changes on an entry. More...

NT_Listener	AddListener (std::span< const std::string_view > prefixes, int eventMask, ListenerCallback listener)
	Add a listener for changes to topics with names that start with any of the given prefixes. More...

static void	RemoveListener (NT_Listener listener)
	Remove a listener. More...

Data Logger Functions
NT_DataLogger	StartEntryDataLog (wpi::log::DataLog &log, std::string_view prefix, std::string_view logPrefix)
	Starts logging entry changes to a DataLog. More...

NT_ConnectionDataLogger	StartConnectionDataLog (wpi::log::DataLog &log, std::string_view name)
	Starts logging connection changes to a DataLog. More...

static void	StopEntryDataLog (NT_DataLogger logger)
	Stops logging entry changes to a DataLog. More...

static void	StopConnectionDataLog (NT_ConnectionDataLogger logger)
	Stops logging connection changes to a DataLog. More...

Detailed Description

NetworkTables Instance.

Instances are completely independent from each other. Table operations on one instance will not be visible to other instances unless the instances are connected via the network. The main limitation on instances is that you cannot have two servers on the same network port. The main utility of instances is for unit testing, but they can also enable one program to connect to two different NetworkTables networks.

The global "default" instance (as returned by GetDefault()) is always available, and is intended for the common case when there is only a single NetworkTables instance being used in the program. The default instance cannot be destroyed.

Additional instances can be created with the Create() function. Instances are not reference counted or RAII. Instead, they must be explicitly destroyed (with Destroy()).

Member Enumeration Documentation

◆ LogLevel

enum nt::NetworkTableInstance::LogLevel

Logging levels (as used by SetLogger()).

Enumerator
kLogCritical
kLogError
kLogWarning
kLogInfo
kLogDebug
kLogDebug1
kLogDebug2
kLogDebug3
kLogDebug4

◆ NetworkMode

enum nt::NetworkTableInstance::NetworkMode

Client/server mode flag values (as returned by GetNetworkMode()).

This is a bitmask.

Enumerator
kNetModeNone
kNetModeServer
kNetModeClient3
kNetModeClient4
kNetModeLocal

Constructor & Destructor Documentation

◆ NetworkTableInstance() [1/2]

nt::NetworkTableInstance::NetworkTableInstance ( )

inlinenoexcept

Construct invalid instance.

◆ NetworkTableInstance() [2/2]

nt::NetworkTableInstance::NetworkTableInstance ( NT_Inst inst )

inlineexplicitnoexcept

Construct from native handle.

Parameters

inst	Native handle

Member Function Documentation

◆ AddConnectionListener()

NT_Listener nt::NetworkTableInstance::AddConnectionListener	(	bool	immediate_notify,
		ListenerCallback	callback
	)		const

inline

Add a connection listener.

The callback function is called asynchronously on a separate thread, so it's important to use synchronization or atomics when accessing any shared state from the callback function.

Parameters

immediate_notify	notify listener of all existing connections
callback	listener to add

Returns: Listener handle

◆ AddListener() [1/5]

NT_Listener nt::NetworkTableInstance::AddListener	(	const NetworkTableEntry &	entry,
		int	eventMask,
		ListenerCallback	listener
	)

Add a listener for changes on an entry.

The callback function is called asynchronously on a separate thread, so it's important to use synchronization or atomics when accessing any shared state from the callback function.

Parameters

entry	Entry
eventMask	Bitmask of EventFlags values
listener	Listener function

Returns: Listener handle

◆ AddListener() [2/5]

NT_Listener nt::NetworkTableInstance::AddListener	(	MultiSubscriber &	subscriber,
		int	eventMask,
		ListenerCallback	listener
	)

Add a listener for changes on a subscriber.

The callback function is called asynchronously on a separate thread, so it's important to use synchronization or atomics when accessing any shared state from the callback function. This does NOT keep the subscriber active.

Parameters

subscriber	Subscriber
eventMask	Bitmask of EventFlags values
listener	Listener function

Returns: Listener handle

◆ AddListener() [3/5]

NT_Listener nt::NetworkTableInstance::AddListener	(	std::span< const std::string_view >	prefixes,
		int	eventMask,
		ListenerCallback	listener
	)

inline

Add a listener for changes to topics with names that start with any of the given prefixes.

The callback function is called asynchronously on a separate thread, so it's important to use synchronization or atomics when accessing any shared state from the callback function.

This creates a corresponding internal subscriber with the lifetime of the listener.

Parameters

prefixes	Topic name string prefixes
eventMask	Bitmask of EventFlags values
listener	Listener function

Returns: Listener handle

◆ AddListener() [4/5]

NT_Listener nt::NetworkTableInstance::AddListener	(	Subscriber &	subscriber,
		unsigned int	eventMask,
		ListenerCallback	listener
	)

Add a listener for changes on a subscriber.

The callback function is called asynchronously on a separate thread, so it's important to use synchronization or atomics when accessing any shared state from the callback function. This does NOT keep the subscriber active.

Parameters

subscriber	Subscriber
eventMask	Bitmask of EventFlags values
listener	Listener function

Returns: Listener handle

◆ AddListener() [5/5]

NT_Listener nt::NetworkTableInstance::AddListener	(	Topic	topic,
		unsigned int	eventMask,
		ListenerCallback	listener
	)

Add a listener for changes on a particular topic.

The callback function is called asynchronously on a separate thread, so it's important to use synchronization or atomics when accessing any shared state from the callback function.

This creates a corresponding internal subscriber with the lifetime of the listener.

Parameters

topic	Topic
eventMask	Bitmask of EventFlags values
listener	Listener function

Returns: Listener handle

◆ AddLogger()

NT_Listener nt::NetworkTableInstance::AddLogger	(	unsigned int	minLevel,
		unsigned int	maxLevel,
		ListenerCallback	func
	)

inline

Add logger callback function.

By default, log messages are sent to stderr; this function sends log messages with the specified levels to the provided callback function instead. The callback function will only be called for log messages with level greater than or equal to minLevel and less than or equal to maxLevel; messages outside this range will be silently ignored.

Parameters

minLevel	minimum log level
maxLevel	maximum log level
func	callback function

Returns: Listener handle

◆ AddProtobufSchema()

template<wpi::ProtobufSerializable T>

void nt::NetworkTableInstance::AddProtobufSchema ( wpi::ProtobufMessage< T > & msg )

Registers a protobuf schema.

Duplicate calls to this function with the same name are silently ignored.

Template Parameters

T	protobuf serializable type

Parameters

msg	protobuf message

◆ AddSchema() [1/2]

void nt::NetworkTableInstance::AddSchema	(	std::string_view	name,
		std::string_view	type,
		std::span< const uint8_t >	schema
	)

inline

Registers a data schema.

Data schemas provide information for how a certain data type string can be decoded. The type string of a data schema indicates the type of the schema itself (e.g. "protobuf" for protobuf schemas, "struct" for struct schemas, etc). In NetworkTables, schemas are published just like normal topics, with the name being generated from the provided name: "/.schema/<name>". Duplicate calls to this function with the same name are silently ignored.

Parameters

name	Name (the string passed as the data type for topics using this schema)
type	Type of schema (e.g. "protobuf", "struct", etc)
schema	Schema data

◆ AddSchema() [2/2]

void nt::NetworkTableInstance::AddSchema	(	std::string_view	name,
		std::string_view	type,
		std::string_view	schema
	)

inline

Registers a data schema.

Data schemas provide information for how a certain data type string can be decoded. The type string of a data schema indicates the type of the schema itself (e.g. "protobuf" for protobuf schemas, "struct" for struct schemas, etc). In NetworkTables, schemas are published just like normal topics, with the name being generated from the provided name: "/.schema/<name>". Duplicate calls to this function with the same name are silently ignored.

Parameters

name	Name (the string passed as the data type for topics using this schema)
type	Type of schema (e.g. "protobuf", "struct", etc)
schema	Schema data

◆ AddStructSchema()

template<typename T , typename... I>
requires wpi::StructSerializable<T, I...>

void nt::NetworkTableInstance::AddStructSchema ( const I &... info )

Registers a struct schema.

Duplicate calls to this function with the same name are silently ignored.

Template Parameters

T	struct serializable type

Parameters

info	optional struct type info

◆ AddTimeSyncListener()

NT_Listener nt::NetworkTableInstance::AddTimeSyncListener	(	bool	immediate_notify,
		ListenerCallback	callback
	)		const

inline

Add a time synchronization listener.

The callback function is called asynchronously on a separate thread, so it's important to use synchronization or atomics when accessing any shared state from the callback function.

Parameters

immediate_notify	notify listener of current time synchronization value
callback	listener to add

Returns: Listener handle

◆ Create()

NetworkTableInstance nt::NetworkTableInstance::Create ( )

inlinestatic

Create an instance.

Returns: Newly created instance

◆ Destroy()

void nt::NetworkTableInstance::Destroy ( NetworkTableInstance & inst )

inlinestatic

Destroys an instance (note: this has global effect).

Parameters

inst Instance

◆ Disconnect()

void nt::NetworkTableInstance::Disconnect ( )

inline

Disconnects the client if it's running and connected.

This will automatically start reconnection attempts to the current server list.

◆ Flush()

void nt::NetworkTableInstance::Flush ( ) const

inline

Flushes all updated values immediately to the network.

Note: This is rate-limited to protect the network from flooding. This is primarily useful for synchronizing network updates with user code.

◆ FlushLocal()

void nt::NetworkTableInstance::FlushLocal ( ) const

inline

Flushes all updated values immediately to the local client/server.

This does not flush to the network.

◆ GetBooleanArrayTopic()

BooleanArrayTopic nt::NetworkTableInstance::GetBooleanArrayTopic ( std::string_view name ) const

Gets a boolean array topic.

Parameters

name	topic name

Returns: Topic

◆ GetBooleanTopic()

BooleanTopic nt::NetworkTableInstance::GetBooleanTopic ( std::string_view name ) const

Gets a boolean topic.

Parameters

name	topic name

Returns: Topic

◆ GetConnections()

std::vector< ConnectionInfo > nt::NetworkTableInstance::GetConnections ( ) const

inline

Get information on the currently established network connections.

If operating as a client, this will return either zero or one values.

Returns: array of connection information

◆ GetDefault()

NetworkTableInstance nt::NetworkTableInstance::GetDefault ( )

inlinestatic

Get global default instance.

Returns: Global default instance

◆ GetDoubleArrayTopic()

DoubleArrayTopic nt::NetworkTableInstance::GetDoubleArrayTopic ( std::string_view name ) const

Gets a double array topic.

Parameters

name	topic name

Returns: Topic

◆ GetDoubleTopic()

DoubleTopic nt::NetworkTableInstance::GetDoubleTopic ( std::string_view name ) const

Gets a double topic.

Parameters

name	topic name

Returns: Topic

◆ GetEntry()

NetworkTableEntry nt::NetworkTableInstance::GetEntry ( std::string_view name )

inline

Gets the entry for a key.

Parameters

name Key

Returns: Network table entry.

◆ GetFloatArrayTopic()

FloatArrayTopic nt::NetworkTableInstance::GetFloatArrayTopic ( std::string_view name ) const

Gets a float array topic.

Parameters

name	topic name

Returns: Topic

◆ GetFloatTopic()

FloatTopic nt::NetworkTableInstance::GetFloatTopic ( std::string_view name ) const

Gets a float topic.

Parameters

name	topic name

Returns: Topic

◆ GetHandle()

NT_Inst nt::NetworkTableInstance::GetHandle ( ) const

inline

Gets the native handle for the entry.

Returns: Native handle

◆ GetIntegerArrayTopic()

IntegerArrayTopic nt::NetworkTableInstance::GetIntegerArrayTopic ( std::string_view name ) const

Gets an integer array topic.

Parameters

name	topic name

Returns: Topic

◆ GetIntegerTopic()

IntegerTopic nt::NetworkTableInstance::GetIntegerTopic ( std::string_view name ) const

Gets an integer topic.

Parameters

name	topic name

Returns: Topic

◆ GetNetworkMode()

unsigned int nt::NetworkTableInstance::GetNetworkMode ( ) const

inline

Get the current network mode.

Returns: Bitmask of NetworkMode.

◆ GetProtobufTopic()

template<wpi::ProtobufSerializable T>

ProtobufTopic< T > nt::NetworkTableInstance::GetProtobufTopic ( std::string_view name ) const

inline

Gets a protobuf serialized value topic.

Parameters

name	topic name

Returns: Topic

◆ GetRawTopic()

RawTopic nt::NetworkTableInstance::GetRawTopic ( std::string_view name ) const

Gets a raw topic.

Parameters

name	topic name

Returns: Topic

◆ GetServerTimeOffset()

std::optional< int64_t > nt::NetworkTableInstance::GetServerTimeOffset ( ) const

inline

Get the time offset between server time and local time.

Add this value to local time to get the estimated equivalent server time. In server mode, this always returns 0. In client mode, this returns the time offset only if the client and server are connected and have exchanged synchronization messages. Note the time offset may change over time as it is periodically updated; to receive updates as events, add a listener to the "time sync" event.

Returns: Time offset in microseconds (optional)

◆ GetStringArrayTopic()

StringArrayTopic nt::NetworkTableInstance::GetStringArrayTopic ( std::string_view name ) const

Gets a string array topic.

Parameters

name	topic name

Returns: Topic

◆ GetStringTopic()

StringTopic nt::NetworkTableInstance::GetStringTopic ( std::string_view name ) const

Gets a string topic.

Parameters

name	topic name

Returns: Topic

◆ GetStructArrayTopic()

template<typename T , typename... I>
requires wpi::StructSerializable<T, I...>

StructArrayTopic< T, I... > nt::NetworkTableInstance::GetStructArrayTopic	(	std::string_view	name,
		I...	info
	)		const

inline

Gets a raw struct serialized array topic.

Parameters

name	topic name
info	optional struct type info

Returns: Topic

◆ GetStructTopic()

template<typename T , typename... I>
requires wpi::StructSerializable<T, I...>

StructTopic< T, I... > nt::NetworkTableInstance::GetStructTopic	(	std::string_view	name,
		I...	info
	)		const

inline

Gets a raw struct serialized value topic.

Parameters

name	topic name
info	optional struct type info

Returns: Topic

◆ GetTable()

std::shared_ptr< NetworkTable > nt::NetworkTableInstance::GetTable ( std::string_view key ) const

Gets the table with the specified key.

Parameters

key	the key name

Returns: The network table

◆ GetTopic()

Topic nt::NetworkTableInstance::GetTopic ( std::string_view name ) const

Gets a "generic" (untyped) topic.

Parameters

name	topic name

Returns: Topic

◆ GetTopicInfo() [1/4]

std::vector< TopicInfo > nt::NetworkTableInstance::GetTopicInfo ( )

inline

Get Topic Information about multiple topics.

Returns an array of topic information (handle, name, type, and properties).

Returns: Array of topic information.

◆ GetTopicInfo() [2/4]

std::vector< TopicInfo > nt::NetworkTableInstance::GetTopicInfo ( std::string_view prefix )

inline

Get Topic Information about multiple topics.

Returns an array of topic information (handle, name, type, and properties). The results are filtered by string prefix to only return a subset of all topics.

Parameters

prefix name required prefix; only topics whose name starts with this string are returned

Returns: Array of topic information.

◆ GetTopicInfo() [3/4]

std::vector< TopicInfo > nt::NetworkTableInstance::GetTopicInfo	(	std::string_view	prefix,
		std::span< std::string_view >	types
	)

inline

Get Topic Information about multiple topics.

Returns an array of topic information (handle, name, type, and properties). The results are filtered by string prefix and type to only return a subset of all topics.

Parameters

prefix	name required prefix; only topics whose name starts with this string are returned
types	array of type strings

Returns: Array of topic information.

◆ GetTopicInfo() [4/4]

std::vector< TopicInfo > nt::NetworkTableInstance::GetTopicInfo	(	std::string_view	prefix,
		unsigned int	types
	)

inline

Get Topic Information about multiple topics.

Returns an array of topic information (handle, name, type, and properties). The results are filtered by string prefix and type to only return a subset of all topics.

Parameters

prefix	name required prefix; only topics whose name starts with this string are returned
types	bitmask of NT_Type values; 0 is treated specially as a "don't care"

Returns: Array of topic information.

◆ GetTopics() [1/4]

std::vector< Topic > nt::NetworkTableInstance::GetTopics ( )

inline

Get Published Topics.

Returns an array of topics.

Returns: Array of topics.

◆ GetTopics() [2/4]

std::vector< Topic > nt::NetworkTableInstance::GetTopics ( std::string_view prefix )

inline

Get Published Topics.

Returns an array of topics. The results are filtered by string prefix to only return a subset of all topics.

Parameters

prefix name required prefix; only topics whose name starts with this string are returned

Returns: Array of topics.

◆ GetTopics() [3/4]

std::vector< Topic > nt::NetworkTableInstance::GetTopics	(	std::string_view	prefix,
		std::span< std::string_view >	types
	)

inline

Get Published Topics.

Returns an array of topics. The results are filtered by string prefix and type to only return a subset of all topics.

Parameters

prefix	name required prefix; only topics whose name starts with this string are returned
types	array of type strings

Returns: Array of topic handles.

◆ GetTopics() [4/4]

std::vector< Topic > nt::NetworkTableInstance::GetTopics	(	std::string_view	prefix,
		unsigned int	types
	)

inline

Get Published Topics.

Returns an array of topics. The results are filtered by string prefix and type to only return a subset of all topics.

Parameters

prefix	name required prefix; only topics whose name starts with this string are returned
types	bitmask of NT_Type values; 0 is treated specially as a "don't care"

Returns: Array of topics.

◆ HasSchema()

bool nt::NetworkTableInstance::HasSchema ( std::string_view name ) const

inline

Returns whether there is a data schema already registered with the given name.

This does NOT perform a check as to whether the schema has already been published by another node on the network.

Parameters

name	Name (the string passed as the data type for topics using this schema)

Returns: True if schema already registered

◆ IsConnected()

bool nt::NetworkTableInstance::IsConnected ( ) const

inline

Return whether or not the instance is connected to another node.

Returns: True if connected.

◆ operator bool()

nt::NetworkTableInstance::operator bool ( ) const

inlineexplicit

Determines if the native handle is valid.

Returns: True if the native handle is valid, false otherwise.

◆ operator==()

bool nt::NetworkTableInstance::operator== ( const NetworkTableInstance & ) const

default

Equality operator.

Returns true if both instances refer to the same native handle.

◆ RemoveListener()

void nt::NetworkTableInstance::RemoveListener ( NT_Listener listener )

inlinestatic

Remove a listener.

Parameters

listener Listener handle to remove

◆ SetServer() [1/3]

void nt::NetworkTableInstance::SetServer	(	const char *	server_name,
		unsigned int	port = `0`
	)

inline

Sets server address and port for client (without restarting client).

Parameters

server_name	server name (UTF-8 string, null terminated)
port	port to communicate over (0 = default)

◆ SetServer() [2/3]

void nt::NetworkTableInstance::SetServer ( std::span< const std::pair< std::string_view, unsigned int > > servers )

inline

Sets server addresses and ports for client (without restarting client).

The client will attempt to connect to each server in round robin fashion.

Parameters

servers array of server address and port pairs

◆ SetServer() [3/3]

void nt::NetworkTableInstance::SetServer	(	std::span< const std::string_view >	servers,
		unsigned int	port = `0`
	)

Sets server addresses and port for client (without restarting client).

The client will attempt to connect to each server in round robin fashion.

Parameters

servers	array of server names
port	port to communicate over (0 = default)

◆ SetServerTeam()

void nt::NetworkTableInstance::SetServerTeam	(	unsigned int	team,
		unsigned int	port = `0`
	)

inline

Sets server addresses and port for client (without restarting client).

Connects using commonly known robot addresses for the specified team.

Parameters

team	team number
port	port to communicate over (0 = default)

◆ StartClient3()

void nt::NetworkTableInstance::StartClient3 ( std::string_view identity )

inline

Starts a NT3 client.

Use SetServer or SetServerTeam to set the server name and port.

Parameters

identity network identity to advertise (cannot be empty string)

◆ StartClient4()

void nt::NetworkTableInstance::StartClient4 ( std::string_view identity )

inline

Starts a NT4 client.

Use SetServer or SetServerTeam to set the server name and port.

Parameters

identity network identity to advertise (cannot be empty string)

◆ StartConnectionDataLog()

NT_ConnectionDataLogger nt::NetworkTableInstance::StartConnectionDataLog	(	wpi::log::DataLog &	log,
		std::string_view	name
	)

inline

Starts logging connection changes to a DataLog.

Parameters

log	data log object; lifetime must extend until StopConnectionDataLog is called or the instance is destroyed
name	data log entry name

Returns: Data logger handle

◆ StartDSClient()

void nt::NetworkTableInstance::StartDSClient ( unsigned int port = 0 )

inline

Starts requesting server address from Driver Station.

This connects to the Driver Station running on localhost to obtain the server IP address.

Parameters

port	server port to use in combination with IP from DS (0 = default)

◆ StartEntryDataLog()

NT_DataLogger nt::NetworkTableInstance::StartEntryDataLog	(	wpi::log::DataLog &	log,
		std::string_view	prefix,
		std::string_view	logPrefix
	)

inline

Starts logging entry changes to a DataLog.

Parameters

log	data log object; lifetime must extend until StopEntryDataLog is called or the instance is destroyed
prefix	only store entries with names that start with this prefix; the prefix is not included in the data log entry name
logPrefix	prefix to add to data log entry names

Returns: Data logger handle

◆ StartLocal()

void nt::NetworkTableInstance::StartLocal ( )

inline

Starts local-only operation.

Prevents calls to StartServer or StartClient from taking effect. Has no effect if StartServer or StartClient has already been called.

◆ StartServer()

void nt::NetworkTableInstance::StartServer	(	std::string_view	persist_filename = `"networktables.json"`,
		const char *	listen_address = `""`,
		unsigned int	port3 = `kDefaultPort3`,
		unsigned int	port4 = `kDefaultPort4`
	)

inline

Starts a server using the specified filename, listening address, and port.

Parameters

persist_filename	the name of the persist file to use (UTF-8 string, null terminated)
listen_address	the address to listen on, or null to listen on any address (UTF-8 string, null terminated)
port3	port to communicate over (NT3)
port4	port to communicate over (NT4)

◆ StopClient()

void nt::NetworkTableInstance::StopClient ( )

inline

Stops the client if it is running.

◆ StopConnectionDataLog()

void nt::NetworkTableInstance::StopConnectionDataLog ( NT_ConnectionDataLogger logger )

inlinestatic

Stops logging connection changes to a DataLog.

Parameters

logger data logger handle

◆ StopDSClient()

void nt::NetworkTableInstance::StopDSClient ( )

inline

Stops requesting server address from Driver Station.

◆ StopEntryDataLog()

void nt::NetworkTableInstance::StopEntryDataLog ( NT_DataLogger logger )

inlinestatic

Stops logging entry changes to a DataLog.

Parameters

logger data logger handle

◆ StopLocal()

void nt::NetworkTableInstance::StopLocal ( )

inline

Stops local-only operation.

StartServer or StartClient can be called after this call to start a server or client.

◆ StopServer()

void nt::NetworkTableInstance::StopServer ( )

inline

Stops the server if it is running.

◆ WaitForListenerQueue()

bool nt::NetworkTableInstance::WaitForListenerQueue ( double timeout )

inline

Wait for the listener queue to be empty.

This is primarily useful for deterministic testing. This blocks until either the listener queue is empty (e.g. there are no more events that need to be passed along to callbacks or poll queues) or the timeout expires.

Parameters

timeout timeout, in seconds. Set to 0 for non-blocking behavior, or a negative value to block indefinitely

Returns: False if timed out, otherwise true.

Member Data Documentation

◆ kDefaultPort3

constexpr unsigned int nt::NetworkTableInstance::kDefaultPort3 = NT_DEFAULT_PORT3

staticconstexpr

The default port that network tables operates on for NT3.

◆ kDefaultPort4

constexpr unsigned int nt::NetworkTableInstance::kDefaultPort4 = NT_DEFAULT_PORT4

staticconstexpr

The default port that network tables operates on for NT4.

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

networktables/NetworkTableInstance.h
networktables/NetworkTableInstance.inc

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Schema Functions

Listener Functions

Data Logger Functions

Detailed Description

Member Enumeration Documentation

◆ LogLevel

◆ NetworkMode

Constructor & Destructor Documentation

◆ NetworkTableInstance() [1/2]

◆ NetworkTableInstance() [2/2]

Member Function Documentation

◆ AddConnectionListener()

◆ AddListener() [1/5]

◆ AddListener() [2/5]

◆ AddListener() [3/5]

◆ AddListener() [4/5]

◆ AddListener() [5/5]

◆ AddLogger()

◆ AddProtobufSchema()

◆ AddSchema() [1/2]

◆ AddSchema() [2/2]

◆ AddStructSchema()

◆ AddTimeSyncListener()

◆ Create()

◆ Destroy()

◆ Disconnect()

◆ Flush()

◆ FlushLocal()

◆ GetBooleanArrayTopic()

◆ GetBooleanTopic()

◆ GetConnections()

◆ GetDefault()

◆ GetDoubleArrayTopic()

◆ GetDoubleTopic()

◆ GetEntry()

◆ GetFloatArrayTopic()

◆ GetFloatTopic()

◆ GetHandle()

◆ GetIntegerArrayTopic()

◆ GetIntegerTopic()

◆ GetNetworkMode()

◆ GetProtobufTopic()

◆ GetRawTopic()

◆ GetServerTimeOffset()

◆ GetStringArrayTopic()

◆ GetStringTopic()

◆ GetStructArrayTopic()

◆ GetStructTopic()

◆ GetTable()

◆ GetTopic()

◆ GetTopicInfo() [1/4]

◆ GetTopicInfo() [2/4]

◆ GetTopicInfo() [3/4]

◆ GetTopicInfo() [4/4]

◆ GetTopics() [1/4]

◆ GetTopics() [2/4]

◆ GetTopics() [3/4]

◆ GetTopics() [4/4]

◆ HasSchema()

◆ IsConnected()

◆ operator bool()

◆ operator==()

◆ RemoveListener()

◆ SetServer() [1/3]

◆ SetServer() [2/3]

◆ SetServer() [3/3]

◆ SetServerTeam()

◆ StartClient3()

◆ StartClient4()

◆ StartConnectionDataLog()

◆ StartDSClient()

◆ StartEntryDataLog()

◆ StartLocal()

◆ StartServer()

◆ StopClient()

◆ StopConnectionDataLog()