Inheritance diagram for org.wpilib.networktables.Topic:

Public Member Functions
boolean	isValid ()
int	getHandle ()
NetworkTableInstance	getInstance ()
String	getName ()
NetworkTableType	getType ()
String	getTypeString ()
TopicInfo	getInfo ()
void	setPersistent (boolean persistent)
boolean	isPersistent ()
void	setRetained (boolean retained)
boolean	isRetained ()
void	setCached (boolean cached)
boolean	isCached ()
boolean	exists ()
String	getProperty (String name)
void	setProperty (String name, String value)
void	deleteProperty (String name)
String	getProperties ()
void	setProperties (String properties)
GenericSubscriber	genericSubscribe (PubSubOption... options)
GenericSubscriber	genericSubscribe (String typeString, PubSubOption... options)
GenericPublisher	genericPublish (String typeString, PubSubOption... options)
GenericPublisher	genericPublishEx (String typeString, String properties, PubSubOption... options)
GenericEntry	getGenericEntry (PubSubOption... options)
GenericEntry	getGenericEntry (String typeString, PubSubOption... options)
boolean	equals (Object other)
int	hashCode ()

Protected Attributes
final NetworkTableInstance	m_inst
final int	m_handle

Detailed Description

NetworkTables Topic.

Definition at line 8 of file Topic.java.

Member Function Documentation

◆ deleteProperty()

void org.wpilib.networktables.Topic.deleteProperty ( String name )

Deletes a property. Has no effect if the property does not exist.

Parameters

name	property name

Definition at line 174 of file Topic.java.

◆ equals()

boolean org.wpilib.networktables.Topic.equals ( Object other )

Definition at line 323 of file Topic.java.

◆ exists()

boolean org.wpilib.networktables.Topic.exists ( )

Determines if the topic is currently being published.

Returns: True if the topic exists, false otherwise.

Definition at line 144 of file Topic.java.

◆ genericPublish()

GenericPublisher org.wpilib.networktables.Topic.genericPublish	(	String	typeString,
		PubSubOption...	options )

Create a new publisher to the topic.

The publisher is only active as long as the returned object is not closed.

It is not possible to publish two different data types to the same topic. Conflicts between publishers are typically resolved by the server on a first-come, first-served basis. Any published values that do not match the topic's data type are dropped (ignored). To determine if the data type matches, use the appropriate Topic functions.

Parameters

typeString	type string
options	publish options

Returns: publisher

Definition at line 245 of file Topic.java.

◆ genericPublishEx()

GenericPublisher org.wpilib.networktables.Topic.genericPublishEx	(	String	typeString,
		String	properties,
		PubSubOption...	options )

Create a new publisher to the topic, with type string and initial properties.

The publisher is only active as long as the returned object is not closed.

It is not possible to publish two different data types to the same topic. Conflicts between publishers are typically resolved by the server on a first-come, first-served basis. Any published values that do not match the topic's data type are dropped (ignored). To determine if the data type matches, use the appropriate Topic functions.

Parameters

typeString	type string
properties	JSON properties
options	publish options

Returns: publisher

Exceptions

IllegalArgumentException if properties is not a JSON object

Definition at line 268 of file Topic.java.

◆ genericSubscribe() [1/2]

GenericSubscriber org.wpilib.networktables.Topic.genericSubscribe ( PubSubOption... options )

Create a new subscriber to the topic.

The subscriber is only active as long as the returned object is not closed.

Parameters

options subscribe options

Returns: subscriber

Definition at line 208 of file Topic.java.

◆ genericSubscribe() [2/2]

GenericSubscriber org.wpilib.networktables.Topic.genericSubscribe	(	String	typeString,
		PubSubOption...	options )

Create a new subscriber to the topic.

The subscriber is only active as long as the returned object is not closed.

Subscribers that do not match the published data type do not return any values. To determine if the data type matches, use the appropriate Topic functions.

Parameters

typeString	type string
options	subscribe options

Returns: subscriber

Definition at line 224 of file Topic.java.

◆ getGenericEntry() [1/2]

GenericEntry org.wpilib.networktables.Topic.getGenericEntry ( PubSubOption... options )

Create a new generic entry for the topic.

Entries act as a combination of a subscriber and a weak publisher. The subscriber is active as long as the entry is not closed. The publisher is created when the entry is first written to, and remains active until either unpublish() is called or the entry is closed.

It is not possible to publish two different data types to the same topic. Conflicts between publishers are typically resolved by the server on a first-come, first-served basis. Any published values that do not match the topic's data type are dropped (ignored). To determine if the data type matches, use the appropriate Topic functions.

Parameters

options publish and/or subscribe options

Returns: entry

Definition at line 295 of file Topic.java.

◆ getGenericEntry() [2/2]

GenericEntry org.wpilib.networktables.Topic.getGenericEntry	(	String	typeString,
		PubSubOption...	options )

Create a new generic entry for the topic.

Entries act as a combination of a subscriber and a weak publisher. The subscriber is active as long as the entry is not closed. The publisher is created when the entry is first written to, and remains active until either unpublish() is called or the entry is closed.

It is not possible to publish two different data types to the same topic. Conflicts between publishers are typically resolved by the server on a first-come, first-served basis. Any published values that do not match the topic's data type are dropped (ignored). To determine if the data type matches, use the appropriate Topic functions.

Parameters

typeString	type string
options	publish and/or subscribe options

Returns: entry

Definition at line 315 of file Topic.java.

◆ getHandle()

int org.wpilib.networktables.Topic.getHandle ( )

Gets the native handle for the topic.

Returns: Native handle

Definition at line 34 of file Topic.java.

◆ getInfo()

TopicInfo org.wpilib.networktables.Topic.getInfo ( )

Gets combined information about the topic.

Returns: Topic information

Definition at line 80 of file Topic.java.

◆ getInstance()

NetworkTableInstance org.wpilib.networktables.Topic.getInstance ( )

Gets the instance for the topic.

Returns: Instance

Definition at line 43 of file Topic.java.

◆ getName()

String org.wpilib.networktables.Topic.getName ( )

Gets the name of the topic.

Returns: the topic's name

Definition at line 52 of file Topic.java.

◆ getProperties()

String org.wpilib.networktables.Topic.getProperties ( )

Gets all topic properties as a JSON object string. Each key in the object is the property name, and the corresponding value is the property value.

Returns: JSON string

Definition at line 184 of file Topic.java.

◆ getProperty()

String org.wpilib.networktables.Topic.getProperty ( String name )

Gets the current value of a property (as a JSON string).

Parameters

name	property name

Returns: JSON string; "null" if the property does not exist.

Definition at line 154 of file Topic.java.

◆ getType()

NetworkTableType org.wpilib.networktables.Topic.getType ( )

Gets the type of the topic.

Returns: the topic's type

Definition at line 61 of file Topic.java.

◆ getTypeString()

String org.wpilib.networktables.Topic.getTypeString ( )

Gets the type string of the topic. This may have more information than the numeric type (especially for raw values).

Returns: the topic's type

Definition at line 71 of file Topic.java.

◆ hashCode()

int org.wpilib.networktables.Topic.hashCode ( )

Definition at line 328 of file Topic.java.

◆ isCached()

boolean org.wpilib.networktables.Topic.isCached ( )

Returns whether the topic's last value is stored.

Returns: True if the topic is cached.

Definition at line 135 of file Topic.java.

◆ isPersistent()

boolean org.wpilib.networktables.Topic.isPersistent ( )

Returns whether the value is persistent through server restarts.

Returns: True if the value is persistent.

Definition at line 98 of file Topic.java.

◆ isRetained()

boolean org.wpilib.networktables.Topic.isRetained ( )

Returns whether the topic is retained by server when there are no publishers.

Returns: True if the topic is retained.

Definition at line 116 of file Topic.java.

◆ isValid()

boolean org.wpilib.networktables.Topic.isValid ( )

Determines if the native handle is valid.

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

Definition at line 25 of file Topic.java.

◆ setCached()

void org.wpilib.networktables.Topic.setCached ( boolean cached )

Allow storage of the topic's last value, allowing the value to be read (and not just accessed through event queues and listeners).

Parameters

cached True for cached, false for not cached.

Definition at line 126 of file Topic.java.

◆ setPersistent()

void org.wpilib.networktables.Topic.setPersistent ( boolean persistent )

Make value persistent through server restarts.

Parameters

persistent True for persistent, false for not persistent.

Definition at line 89 of file Topic.java.

◆ setProperties()

void org.wpilib.networktables.Topic.setProperties ( String properties )

Updates multiple topic properties. Each key in the passed-in object is the name of the property to add/update, and the corresponding value is the property value to set for that property. Null values result in deletion of the corresponding property.

Parameters

properties JSON object string with keys to add/update/delete

Exceptions

IllegalArgumentException if properties is not a JSON object

Definition at line 196 of file Topic.java.

◆ setProperty()

void org.wpilib.networktables.Topic.setProperty	(	String	name,
		String	value )

Sets a property value.

Parameters

name	property name
value	property value (JSON string)

Exceptions

IllegalArgumentException if properties is not parseable as JSON

Definition at line 165 of file Topic.java.

◆ setRetained()

void org.wpilib.networktables.Topic.setRetained ( boolean retained )

Make the server retain the topic even when there are no publishers.

Parameters

retained True for retained, false for not retained.

Definition at line 107 of file Topic.java.

Member Data Documentation

◆ m_handle

final int org.wpilib.networktables.Topic.m_handle

protected

NetworkTables handle.

Definition at line 336 of file Topic.java.

◆ m_inst

final NetworkTableInstance org.wpilib.networktables.Topic.m_inst

protected

NetworkTables instance.

Definition at line 333 of file Topic.java.

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

org/wpilib/networktables/Topic.java

Public Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

◆ deleteProperty()

◆ equals()

◆ exists()

◆ genericPublish()

◆ genericPublishEx()

◆ genericSubscribe() [1/2]

◆ genericSubscribe() [2/2]

◆ getGenericEntry() [1/2]

◆ getGenericEntry() [2/2]

◆ getHandle()

◆ getInfo()

◆ getInstance()

◆ getName()

◆ getProperties()

◆ getProperty()

◆ getType()

◆ getTypeString()

◆ hashCode()

◆ isCached()

◆ isPersistent()

◆ isRetained()

◆ isValid()

◆ setCached()

◆ setPersistent()

◆ setProperties()

◆ setProperty()

◆ setRetained()

Member Data Documentation

◆ m_handle

◆ m_inst