A network table that knows its subtable path. More...

#include <networktables/NetworkTable.h>

Public Types
using	TableEventListener = std::function< void(NetworkTable *table, std::string_view key, const Event &event)>
	Called when an event occurs on a topic in a `NetworkTable`. More...

using	SubTableListener = std::function< void(NetworkTable *parent, std::string_view name, std::shared_ptr< NetworkTable > table)>
	Called when a new table is created within a NetworkTable. More...

Public Member Functions
	NetworkTable (NT_Inst inst, std::string_view path, const private_init &)
	Constructor. More...

	~NetworkTable ()

NetworkTableInstance	GetInstance () const
	Gets the instance for the table. More...

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

Topic	GetTopic (std::string_view name) const
	Get (generic) topic. More...

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

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

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

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

StringTopic	GetStringTopic (std::string_view name) const
	Get String topic. More...

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

BooleanArrayTopic	GetBooleanArrayTopic (std::string_view name) const
	Get boolean[] topic. More...

IntegerArrayTopic	GetIntegerArrayTopic (std::string_view name) const
	Get integer[] topic. More...

FloatArrayTopic	GetFloatArrayTopic (std::string_view name) const
	Get float[] topic. More...

DoubleArrayTopic	GetDoubleArrayTopic (std::string_view name) const
	Get double[] topic. More...

StringArrayTopic	GetStringArrayTopic (std::string_view name) const
	Get String[] topic. More...

std::shared_ptr< NetworkTable >	GetSubTable (std::string_view key) const
	Returns the table at the specified key. More...

bool	ContainsKey (std::string_view key) const
	Determines whether the given key is in this table. More...

bool	ContainsSubTable (std::string_view key) const
	Determines whether there exists a non-empty subtable for this key in this table. More...

std::vector< TopicInfo >	GetTopicInfo (int types=0) const
	Gets topic information for all keys in the table (not including sub-tables). More...

std::vector< Topic >	GetTopics (int types=0) const
	Gets all topics in the table (not including sub-tables). More...

std::vector< std::string >	GetKeys (int types=0) const
	Gets all keys in the table (not including sub-tables). More...

std::vector< std::string >	GetSubTables () const
	Gets the names of all subtables in the table. More...

void	SetPersistent (std::string_view key)
	Makes a key's value persistent through program restarts. More...

void	ClearPersistent (std::string_view key)
	Stop making a key's value persistent through program restarts. More...

bool	IsPersistent (std::string_view key) const
	Returns whether the value is persistent through program restarts. More...

bool	PutNumber (std::string_view key, double value)
	Put a number in the table. More...

bool	SetDefaultNumber (std::string_view key, double defaultValue)
	Gets the current value in the table, setting it if it does not exist. More...

double	GetNumber (std::string_view key, double defaultValue) const
	Gets the number associated with the given name. More...

bool	PutString (std::string_view key, std::string_view value)
	Put a string in the table. More...

bool	SetDefaultString (std::string_view key, std::string_view defaultValue)
	Gets the current value in the table, setting it if it does not exist. More...

std::string	GetString (std::string_view key, std::string_view defaultValue) const
	Gets the string associated with the given name. More...

bool	PutBoolean (std::string_view key, bool value)
	Put a boolean in the table. More...

bool	SetDefaultBoolean (std::string_view key, bool defaultValue)
	Gets the current value in the table, setting it if it does not exist. More...

bool	GetBoolean (std::string_view key, bool defaultValue) const
	Gets the boolean associated with the given name. More...

bool	PutBooleanArray (std::string_view key, std::span< const int > value)
	Put a boolean array in the table. More...

bool	SetDefaultBooleanArray (std::string_view key, std::span< const int > defaultValue)
	Gets the current value in the table, setting it if it does not exist. More...

std::vector< int >	GetBooleanArray (std::string_view key, std::span< const int > defaultValue) const
	Returns the boolean array the key maps to. More...

bool	PutNumberArray (std::string_view key, std::span< const double > value)
	Put a number array in the table. More...

bool	SetDefaultNumberArray (std::string_view key, std::span< const double > defaultValue)
	Gets the current value in the table, setting it if it does not exist. More...

std::vector< double >	GetNumberArray (std::string_view key, std::span< const double > defaultValue) const
	Returns the number array the key maps to. More...

bool	PutStringArray (std::string_view key, std::span< const std::string > value)
	Put a string array in the table. More...

bool	SetDefaultStringArray (std::string_view key, std::span< const std::string > defaultValue)
	Gets the current value in the table, setting it if it does not exist. More...

std::vector< std::string >	GetStringArray (std::string_view key, std::span< const std::string > defaultValue) const
	Returns the string array the key maps to. More...

bool	PutRaw (std::string_view key, std::span< const uint8_t > value)
	Put a raw value (byte array) in the table. More...

bool	SetDefaultRaw (std::string_view key, std::span< const uint8_t > defaultValue)
	Gets the current value in the table, setting it if it does not exist. More...

std::vector< uint8_t >	GetRaw (std::string_view key, std::span< const uint8_t > defaultValue) const
	Returns the raw value (byte array) the key maps to. More...

bool	PutValue (std::string_view key, const Value &value)
	Put a value in the table. More...

bool	SetDefaultValue (std::string_view key, const Value &defaultValue)
	Gets the current value in the table, setting it if it does not exist. More...

Value	GetValue (std::string_view key) const
	Gets the value associated with a key as an object. More...

std::string_view	GetPath () const
	Gets the full path of this table. More...

NT_Listener	AddListener (int eventMask, TableEventListener listener)
	Listen to topics only within this table. More...

NT_Listener	AddListener (std::string_view key, int eventMask, TableEventListener listener)
	Listen to a single key. More...

NT_Listener	AddSubTableListener (SubTableListener listener)
	Listen for sub-table creation. More...

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

Static Public Member Functions
static std::string_view	BasenameKey (std::string_view key)
	Gets the "base name" of a key. More...

static std::string	NormalizeKey (std::string_view key, bool withLeadingSlash=true)
	Normalizes an network table key to contain no consecutive slashes and optionally start with a leading slash. More...

static std::string_view	NormalizeKey (std::string_view key, wpi::SmallVectorImpl< char > &buf, bool withLeadingSlash=true)

static std::vector< std::string >	GetHierarchy (std::string_view key)
	Gets a list of the names of all the super tables of a given key. More...

Static Public Attributes
static constexpr char	PATH_SEPARATOR_CHAR = '/'
	The path separator for sub-tables and keys. More...

Friends
class	NetworkTableInstance

Detailed Description

A network table that knows its subtable path.

Member Typedef Documentation

◆ SubTableListener

using nt::NetworkTable::SubTableListener = std::function<void(NetworkTable* parent, std::string_view name, std::shared_ptr<NetworkTable> table)>

Called when a new table is created within a NetworkTable.

Parameters

parent	the parent of the table
name	the name of the new table
table	the new table

◆ TableEventListener

using nt::NetworkTable::TableEventListener = std::function<void( NetworkTable* table, std::string_view key, const Event& event)>

Called when an event occurs on a topic in a NetworkTable.

Parameters

table	the table the topic exists in
key	the key associated with the topic that changed
event	the event

Constructor & Destructor Documentation

◆ NetworkTable()

nt::NetworkTable::NetworkTable	(	NT_Inst	inst,
		std::string_view	path,
		const private_init &
	)

Constructor.

Use NetworkTableInstance::GetTable() or GetSubTable() instead.

◆ ~NetworkTable()

nt::NetworkTable::~NetworkTable ( )

Member Function Documentation

◆ AddListener() [1/2]

NT_Listener nt::NetworkTable::AddListener	(	int	eventMask,
		TableEventListener	listener
	)

Listen to topics only within this table.

Parameters

eventMask	Bitmask of EventFlags values
listener	listener to add

Returns: Listener handle

◆ AddListener() [2/2]

NT_Listener nt::NetworkTable::AddListener	(	std::string_view	key,
		int	eventMask,
		TableEventListener	listener
	)

Listen to a single key.

Parameters

key	the key name
eventMask	Bitmask of EventFlags values
listener	listener to add

Returns: Listener handle

◆ AddSubTableListener()

NT_Listener nt::NetworkTable::AddSubTableListener ( SubTableListener listener )

Listen for sub-table creation.

This calls the listener once for each newly created sub-table. It immediately calls the listener for any existing sub-tables.

Parameters

listener listener to add

Returns: Listener handle

◆ BasenameKey()

static std::string_view nt::NetworkTable::BasenameKey ( std::string_view key )

static

Gets the "base name" of a key.

For example, "/foo/bar" becomes "bar". If the key has a trailing slash, returns an empty string.

Parameters

key key

Returns: base name

◆ ClearPersistent()

void nt::NetworkTable::ClearPersistent ( std::string_view key )

Stop making a key's value persistent through program restarts.

The key cannot be null.

Parameters

key	the key name

◆ ContainsKey()

bool nt::NetworkTable::ContainsKey ( std::string_view key ) const

Determines whether the given key is in this table.

Parameters

key	the key to search for

Returns: true if the table as a value assigned to the given key

◆ ContainsSubTable()

bool nt::NetworkTable::ContainsSubTable ( std::string_view key ) const

Determines whether there exists a non-empty subtable for this key in this table.

Parameters

key	the key to search for

Returns: true if there is a subtable with the key which contains at least one key/subtable of its own

◆ GetBoolean()

bool nt::NetworkTable::GetBoolean	(	std::string_view	key,
		bool	defaultValue
	)		const

Gets the boolean associated with the given name.

If the key does not exist or is of different type, it will return the default value.

Parameters

key	the key to look up
defaultValue	the value to be returned if no value is found

Returns: the value associated with the given key or the given default value if there is no value associated with the key

◆ GetBooleanArray()

std::vector< int > nt::NetworkTable::GetBooleanArray	(	std::string_view	key,
		std::span< const int >	defaultValue
	)		const

Returns the boolean array the key maps to.

If the key does not exist or is of different type, it will return the default value.

Parameters

key	the key to look up
defaultValue	the value to be returned if no value is found

Returns: the value associated with the given key or the given default value if there is no value associated with the key

Note: This makes a copy of the array. If the overhead of this is a concern, use GetValue() instead.; The returned array is std::vector<int> instead of std::vector<bool> because std::vector<bool> is special-cased in C++. 0 is false, any non-zero value is true.

◆ GetBooleanArrayTopic()

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

Get boolean[] topic.

Parameters

name	topic name

Returns: BooleanArrayTopic

◆ GetBooleanTopic()

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

Get boolean topic.

Parameters

name	topic name

Returns: BooleanTopic

◆ GetDoubleArrayTopic()

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

Get double[] topic.

Parameters

name	topic name

Returns: DoubleArrayTopic

◆ GetDoubleTopic()

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

Get double topic.

Parameters

name	topic name

Returns: DoubleTopic

◆ GetEntry()

NetworkTableEntry nt::NetworkTable::GetEntry ( std::string_view key ) const

Gets the entry for a subkey.

Parameters

key	the key name

Returns: Network table entry.

◆ GetFloatArrayTopic()

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

Get float[] topic.

Parameters

name	topic name

Returns: FloatArrayTopic

◆ GetFloatTopic()

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

Get float topic.

Parameters

name	topic name

Returns: FloatTopic

◆ GetHierarchy()

static std::vector< std::string > nt::NetworkTable::GetHierarchy ( std::string_view key )

static

Gets a list of the names of all the super tables of a given key.

For example, the key "/foo/bar/baz" has a hierarchy of "/", "/foo", "/foo/bar", and "/foo/bar/baz".

Parameters

key the key

Returns: List of super tables

◆ GetInstance()

NetworkTableInstance nt::NetworkTable::GetInstance ( ) const

Gets the instance for the table.

Returns: Instance

◆ GetIntegerArrayTopic()

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

Get integer[] topic.

Parameters

name	topic name

Returns: IntegerArrayTopic

◆ GetIntegerTopic()

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

Get integer topic.

Parameters

name	topic name

Returns: IntegerTopic

◆ GetKeys()

std::vector< std::string > nt::NetworkTable::GetKeys ( int types = 0 ) const

Gets all keys in the table (not including sub-tables).

Parameters

types bitmask of types; 0 is treated as a "don't care".

Returns: keys currently in the table

◆ GetNumber()

double nt::NetworkTable::GetNumber	(	std::string_view	key,
		double	defaultValue
	)		const

Gets the number associated with the given name.

Parameters

key	the key to look up
defaultValue	the value to be returned if no value is found

Returns: the value associated with the given key or the given default value if there is no value associated with the key

◆ GetNumberArray()

std::vector< double > nt::NetworkTable::GetNumberArray	(	std::string_view	key,
		std::span< const double >	defaultValue
	)		const

Returns the number array the key maps to.

If the key does not exist or is of different type, it will return the default value.

Parameters

key	the key to look up
defaultValue	the value to be returned if no value is found

Returns: the value associated with the given key or the given default value if there is no value associated with the key

Note: This makes a copy of the array. If the overhead of this is a concern, use GetValue() instead.

◆ GetPath()

std::string_view nt::NetworkTable::GetPath ( ) const

Gets the full path of this table.

Does not include the trailing "/".

Returns: The path (e.g "", "/foo").

◆ GetRaw()

std::vector< uint8_t > nt::NetworkTable::GetRaw	(	std::string_view	key,
		std::span< const uint8_t >	defaultValue
	)		const

Returns the raw value (byte array) the key maps to.

If the key does not exist or is of different type, it will return the default value.

Parameters

key	the key to look up
defaultValue	the value to be returned if no value is found

Returns: the value associated with the given key or the given default value if there is no value associated with the key

Note: This makes a copy of the raw contents. If the overhead of this is a concern, use GetValue() instead.

◆ GetRawTopic()

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

Get raw topic.

Parameters

name	topic name

Returns: BooleanArrayTopic

◆ GetString()

std::string nt::NetworkTable::GetString	(	std::string_view	key,
		std::string_view	defaultValue
	)		const

Gets the string associated with the given name.

If the key does not exist or is of different type, it will return the default value.

Parameters

key	the key to look up
defaultValue	the value to be returned if no value is found

Returns: the value associated with the given key or the given default value if there is no value associated with the key

◆ GetStringArray()

std::vector< std::string > nt::NetworkTable::GetStringArray	(	std::string_view	key,
		std::span< const std::string >	defaultValue
	)		const

Returns the string array the key maps to.

If the key does not exist or is of different type, it will return the default value.

Parameters

key	the key to look up
defaultValue	the value to be returned if no value is found

Returns: the value associated with the given key or the given default value if there is no value associated with the key

Note: This makes a copy of the array. If the overhead of this is a concern, use GetValue() instead.

◆ GetStringArrayTopic()

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

Get String[] topic.

Parameters

name	topic name

Returns: StringArrayTopic

◆ GetStringTopic()

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

Get String topic.

Parameters

name	topic name

Returns: StringTopic

◆ GetSubTable()

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

Returns the table at the specified key.

If there is no table at the specified key, it will create a new table

Parameters

key	the key name

Returns: the networktable to be returned

◆ GetSubTables()

std::vector< std::string > nt::NetworkTable::GetSubTables ( ) const

Gets the names of all subtables in the table.

Returns: subtables currently in the table

◆ GetTopic()

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

Get (generic) topic.

Parameters

name	topic name

Returns: Topic

◆ GetTopicInfo()

std::vector< TopicInfo > nt::NetworkTable::GetTopicInfo ( int types = 0 ) const

Gets topic information for all keys in the table (not including sub-tables).

Parameters

types bitmask of types; 0 is treated as a "don't care".

Returns: topic information for keys currently in the table

◆ GetTopics()

std::vector< Topic > nt::NetworkTable::GetTopics ( int types = 0 ) const

Gets all topics in the table (not including sub-tables).

Parameters

types bitmask of types; 0 is treated as a "don't care".

Returns: topic for keys currently in the table

◆ GetValue()

Value nt::NetworkTable::GetValue ( std::string_view key ) const

Gets the value associated with a key as an object.

Parameters

key	the key of the value to look up

Returns: the value associated with the given key, or nullptr if the key does not exist

◆ IsPersistent()

bool nt::NetworkTable::IsPersistent ( std::string_view key ) const

Returns whether the value is persistent through program restarts.

The key cannot be null.

Parameters

key	the key name

◆ NormalizeKey() [1/2]

static std::string nt::NetworkTable::NormalizeKey	(	std::string_view	key,
		bool	withLeadingSlash = `true`
	)

static

Normalizes an network table key to contain no consecutive slashes and optionally start with a leading slash.

For example:


normalizeKey("/foo/bar", true)  == "/foo/bar"
normalizeKey("foo/bar", true)   == "/foo/bar"
normalizeKey("/foo/bar", false) == "foo/bar"
normalizeKey("foo//bar", false) == "foo/bar"

Parameters

key	the key to normalize
withLeadingSlash	whether or not the normalized key should begin with a leading slash

Returns: normalized key

◆ NormalizeKey() [2/2]

static std::string_view nt::NetworkTable::NormalizeKey	(	std::string_view	key,
		wpi::SmallVectorImpl< char > &	buf,
		bool	withLeadingSlash = `true`
	)

static

◆ PutBoolean()

bool nt::NetworkTable::PutBoolean	(	std::string_view	key,
		bool	value
	)

Put a boolean in the table.

Parameters

key	the key to be assigned to
value	the value that will be assigned

Returns: False if the table key already exists with a different type

◆ PutBooleanArray()

bool nt::NetworkTable::PutBooleanArray	(	std::string_view	key,
		std::span< const int >	value
	)

Put a boolean array in the table.

Parameters

key	the key to be assigned to
value	the value that will be assigned

Returns: False if the table key already exists with a different type

Note: The array must be of int's rather than of bool's because std::vector<bool> is special-cased in C++. 0 is false, any non-zero value is true.

◆ PutNumber()

bool nt::NetworkTable::PutNumber	(	std::string_view	key,
		double	value
	)

Put a number in the table.

Parameters

key	the key to be assigned to
value	the value that will be assigned

Returns: False if the table key already exists with a different type

◆ PutNumberArray()

bool nt::NetworkTable::PutNumberArray	(	std::string_view	key,
		std::span< const double >	value
	)

Put a number array in the table.

Parameters

key	the key to be assigned to
value	the value that will be assigned

Returns: False if the table key already exists with a different type

◆ PutRaw()

bool nt::NetworkTable::PutRaw	(	std::string_view	key,
		std::span< const uint8_t >	value
	)

Put a raw value (byte array) in the table.

Parameters

key	the key to be assigned to
value	the value that will be assigned

Returns: False if the table key already exists with a different type

◆ PutString()

bool nt::NetworkTable::PutString	(	std::string_view	key,
		std::string_view	value
	)

Put a string in the table.

Parameters

key	the key to be assigned to
value	the value that will be assigned

Returns: False if the table key already exists with a different type

◆ PutStringArray()

bool nt::NetworkTable::PutStringArray	(	std::string_view	key,
		std::span< const std::string >	value
	)

Put a string array in the table.

Parameters

key	the key to be assigned to
value	the value that will be assigned

Returns: False if the table key already exists with a different type

◆ PutValue()

bool nt::NetworkTable::PutValue	(	std::string_view	key,
		const Value &	value
	)

Put a value in the table.

Parameters

key	the key to be assigned to
value	the value that will be assigned

Returns: False if the table key already exists with a different type

◆ RemoveListener()

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

Remove a listener.

Parameters

listener listener handle