Abstract base class for Behavior Tree Nodes. More...

#include <tree_node.h>

Inheritance diagram for BT::TreeNode:

[legend]

Classes
struct	PImpl

Public Types
using	PostTickCallback = std::function< NodeStatus(TreeNode &, NodeStatus)>

using	PreTickCallback = std::function< NodeStatus(TreeNode &)>

typedef std::shared_ptr< TreeNode >	Ptr

using	StatusChangeCallback = StatusChangeSignal::CallableFunction

using	StatusChangeSignal = Signal< TimePoint, const TreeNode &, NodeStatus, NodeStatus >

using	StatusChangeSubscriber = StatusChangeSignal::Subscriber

using	TickMonitorCallback = std::function< void(TreeNode &, NodeStatus, std::chrono::microseconds)>

Public Member Functions
const NodeConfig &	config () const

void	emitWakeUpSignal ()
	Notify that the tree should be ticked again() More...

virtual BT::NodeStatus	executeTick ()
	The method that should be used to invoke tick() and setStatus();. More...

const std::string &	fullPath () const

template<typename T >
Expected< T >	getInput (const std::string &key) const

template<typename T >
Result	getInput (const std::string &key, T &destination) const

template<typename T >
Expected< StampedValue< T > >	getInputStamped (const std::string &key) const

template<typename T >
Expected< Timestamp >	getInputStamped (const std::string &key, T &destination) const
	getInputStamped is similar to getInput(dey, destination), but it returne also the Timestamp object, that can be used to check if a value was updated and when. More...

AnyPtrLocked	getLockedPortContent (const std::string &key)
	getLockedPortContent should be used when: More...

StringView	getRawPortValue (const std::string &key) const

void	haltNode ()

bool	isHalted () const

const std::string &	name () const
	Name of the instance, not the type. More...

TreeNode &	operator= (const TreeNode &other)=delete

TreeNode &	operator= (TreeNode &&other) noexcept

const std::string &	registrationName () const
	registrationName is the ID used by BehaviorTreeFactory to create an instance. More...

bool	requiresWakeUp () const

template<typename T >
Result	setOutput (const std::string &key, const T &value)
	setOutput modifies the content of an Output port More...

void	setPostTickFunction (PostTickCallback callback)

void	setPreTickFunction (PreTickCallback callback)

void	setTickMonitorCallback (TickMonitorCallback callback)

NodeStatus	status () const

StatusChangeSubscriber	subscribeToStatusChange (StatusChangeCallback callback)
	subscribeToStatusChange is used to attach a callback to a status change. When StatusChangeSubscriber goes out of scope (it is a shared_ptr) the callback is unsubscribed automatically. More...

	TreeNode (const TreeNode &other)=delete

	TreeNode (std::string name, NodeConfig config)
	TreeNode main constructor. More...

	TreeNode (TreeNode &&other) noexcept

virtual NodeType	type () const =0

uint16_t	UID () const

BT::NodeStatus	waitValidStatus ()

virtual	~TreeNode ()

Static Public Member Functions
static Expected< StringView >	getRemappedKey (StringView port_name, StringView remapped_port)

template<class DerivedT , typename... ExtraArgs>
static std::unique_ptr< TreeNode >	Instantiate (const std::string &name, const NodeConfig &config, ExtraArgs... args)

static bool	isBlackboardPointer (StringView str, StringView *stripped_pointer=nullptr)
	Check a string and return true if it matches the pattern: {...}. More...

static StringView	stripBlackboardPointer (StringView str)

Protected Types
using	PostScripts = std::array< ScriptFunction, size_t(PostCond::COUNT_)>

using	PreScripts = std::array< ScriptFunction, size_t(PreCond::COUNT_)>

Protected Member Functions
NodeConfig &	config ()

void	modifyPortsRemapping (const PortsRemapping &new_remapping)

template<typename T >
T	parseString (const std::string &str) const

PostScripts &	postConditionsScripts ()

PreScripts &	preConditionsScripts ()

void	resetStatus ()
	Set the status to IDLE. More...

void	setRegistrationID (StringView ID)

void	setStatus (NodeStatus new_status)
	setStatus changes the status of the node. it will throw if you try to change the status to IDLE, because your parent node should do that, not the user! More...

void	setWakeUpInstance (std::shared_ptr< WakeUpSignal > instance)

virtual BT::NodeStatus	tick ()=0
	Method to be implemented by the user. More...

Private Member Functions
void	checkPostConditions (NodeStatus status)

Expected< NodeStatus >	checkPreConditions ()

virtual void	halt ()=0

Private Attributes
std::unique_ptr< PImpl >	_p

Friends
class	BehaviorTreeFactory

class	ControlNode

class	DecoratorNode

class	Tree

Detailed Description

Abstract base class for Behavior Tree Nodes.

Definition at line 118 of file tree_node.h.

Member Typedef Documentation

◆ PostScripts

using BT::TreeNode::PostScripts = std::array<ScriptFunction, size_t(PostCond::COUNT_)>

protected

Definition at line 395 of file tree_node.h.

◆ PostTickCallback

using BT::TreeNode::PostTickCallback = std::function<NodeStatus(TreeNode&, NodeStatus)>

Definition at line 166 of file tree_node.h.

◆ PreScripts

using BT::TreeNode::PreScripts = std::array<ScriptFunction, size_t(PreCond::COUNT_)>

protected

Definition at line 394 of file tree_node.h.

◆ PreTickCallback

using BT::TreeNode::PreTickCallback = std::function<NodeStatus(TreeNode&)>

Definition at line 165 of file tree_node.h.

◆ Ptr

typedef std::shared_ptr<TreeNode> BT::TreeNode::Ptr

Definition at line 121 of file tree_node.h.

◆ StatusChangeCallback

using BT::TreeNode::StatusChangeCallback = StatusChangeSignal::CallableFunction

Definition at line 163 of file tree_node.h.

◆ StatusChangeSignal

using BT::TreeNode::StatusChangeSignal = Signal<TimePoint, const TreeNode&, NodeStatus, NodeStatus>

Definition at line 161 of file tree_node.h.

◆ StatusChangeSubscriber

using BT::TreeNode::StatusChangeSubscriber = StatusChangeSignal::Subscriber

Definition at line 162 of file tree_node.h.

◆ TickMonitorCallback

using BT::TreeNode::TickMonitorCallback = std::function<void(TreeNode&, NodeStatus, std::chrono::microseconds)>

Definition at line 168 of file tree_node.h.

Constructor & Destructor Documentation

◆ TreeNode() [1/3]

BT::TreeNode::TreeNode	(	std::string	name,
		NodeConfig	config
	)

TreeNode main constructor.

Parameters

name	name of the instance, not the type.
config	information about input/output ports. See NodeConfig

Note: If your custom node has ports, the derived class must implement:

static PortsList providedPorts();

Definition at line 53 of file tree_node.cpp.

◆ TreeNode() [2/3]

BT::TreeNode::TreeNode ( const TreeNode & other )

delete

◆ TreeNode() [3/3]

BT::TreeNode::TreeNode ( TreeNode && other )

noexcept

Definition at line 57 of file tree_node.cpp.

◆ ~TreeNode()

BT::TreeNode::~TreeNode ( )

virtual

Definition at line 68 of file tree_node.cpp.

Member Function Documentation

◆ checkPostConditions()

void BT::TreeNode::checkPostConditions ( NodeStatus status )

private

Definition at line 246 of file tree_node.cpp.

◆ checkPreConditions()

Expected< NodeStatus > BT::TreeNode::checkPreConditions ( )

private

Definition at line 193 of file tree_node.cpp.

◆ config() [1/2]

NodeConfig& BT::TreeNode::config ( )

protected

◆ config() [2/2]

NodeConfig & BT::TreeNode::config ( ) const

Configuration passed at construction time. Can never change after the creation of the TreeNode instance.

Definition at line 351 of file tree_node.cpp.

◆ emitWakeUpSignal()

void BT::TreeNode::emitWakeUpSignal ( )

Notify that the tree should be ticked again()

Definition at line 426 of file tree_node.cpp.

◆ executeTick()

NodeStatus BT::TreeNode::executeTick ( )

virtual

The method that should be used to invoke tick() and setStatus();.

Reimplemented in BT::CoroActionNode, BT::ThreadedAction, BT::SyncActionNode, and BT::DecoratorNode.

Definition at line 71 of file tree_node.cpp.

◆ fullPath()

const std::string & BT::TreeNode::fullPath ( ) const

Human readable identifier, that includes the hierarchy of Subtrees See tutorial 10 as an example.

Definition at line 341 of file tree_node.cpp.

◆ getInput() [1/2]

template<typename T >

Expected<T> BT::TreeNode::getInput ( const std::string & key ) const

inline

Same as bool getInput(const std::string& key, T& destination) but using optional.

Parameters

key	the name of the port.

Definition at line 257 of file tree_node.h.

◆ getInput() [2/2]

template<typename T >

Result BT::TreeNode::getInput	(	const std::string &	key,
		T &	destination
	)		const

inline

Read an input port, which, in practice, is an entry in the blackboard. If the blackboard contains a std::string and T is not a string, convertFromString<T>() is used automatically to parse the text.

Parameters

key	the name of the port.
destination	reference to the object where the value should be stored

Returns: false if an error occurs.

Definition at line 547 of file tree_node.h.

◆ getInputStamped() [1/2]

template<typename T >

Expected<StampedValue<T> > BT::TreeNode::getInputStamped ( const std::string & key ) const

inline

Same as bool getInputStamped(const std::string& key, T& destination) but return StampedValue<T>

Parameters

key	the name of the port.

Definition at line 270 of file tree_node.h.

◆ getInputStamped() [2/2]

template<typename T >

Expected< Timestamp > BT::TreeNode::getInputStamped	(	const std::string &	key,
		T &	destination
	)		const

inline

getInputStamped is similar to getInput(dey, destination), but it returne also the Timestamp object, that can be used to check if a value was updated and when.

Parameters

key	the name of the port.
destination	reference to the object where the value should be stored

Definition at line 438 of file tree_node.h.

◆ getLockedPortContent()

AnyPtrLocked BT::TreeNode::getLockedPortContent ( const std::string & key )

getLockedPortContent should be used when:

your port contains an object with reference semantic (usually a smart pointer)
you want to modify the object we are pointing to.
you are concerned about thread-safety.

For example, if your port has type std::shared_ptr<Foo>, the code below is NOT thread safe:

auto foo_ptr = getInput<std::shared_ptr<Foo>>("port_name"); // modifying the content of foo_ptr is NOT thread-safe

What you must do, instead, to guaranty thread-safety, is:

if(auto any_ref = getLockedPortContent("port_name")) { Any* any = any_ref.get(); auto foo_ptr = any->cast<std::shared_ptr<Foo>>(); // modifying the content of foo_ptr inside this scope IS thread-safe }

It is important to destroy the object AnyPtrLocked, to release the lock.

NOTE: this method doesn't work, if the port contains a static string, instead of a blackboard pointer.

Parameters

key	the identifier of the port.

Returns: empty AnyPtrLocked if the blackboard entry doesn't exist or the content of the port was a static string.

Definition at line 502 of file tree_node.cpp.

◆ getRawPortValue()

StringView BT::TreeNode::getRawPortValue ( const std::string & key ) const

Definition at line 361 of file tree_node.cpp.

◆ getRemappedKey()

Expected< StringView > BT::TreeNode::getRemappedKey	(	StringView	port_name,
		StringView	remapped_port
	)

static

Definition at line 411 of file tree_node.cpp.

◆ halt()

virtual void BT::TreeNode::halt ( )

privatepure virtual

The method used to interrupt the execution of a RUNNING node. Only Async nodes that may return RUNNING should implement it.

Implemented in BT::StatefulActionNode, BT::SyncActionNode, BT::ConditionNode, BT::CoroActionNode, FollowPath, BT::ThreadedAction, BT::TimeoutNode, BT::ParallelNode, BT::RepeatNode, BT::SwitchNode< NUM_CASES >, BT::RetryNode, BT::DelayNode, BT::AsyncActionTest, BT::ParallelAllNode, BT::ReactiveFallback, BT::ReactiveSequence, BT::EntryUpdatedDecorator, BT::ControlNode, BT::IfThenElseNode, BT::SequenceNode, BT::SequenceWithMemory, BT::WhileDoElseNode, BT::FallbackNode, BT::ManualSelectorNode, BT::DecoratorNode, and SimpleCoroAction.

◆ haltNode()

void BT::TreeNode::haltNode ( )

Definition at line 148 of file tree_node.cpp.

◆ Instantiate()

template<class DerivedT , typename... ExtraArgs>

static std::unique_ptr<TreeNode> BT::TreeNode::Instantiate	(	const std::string &	name,
		const NodeConfig &	config,
		ExtraArgs...	args
	)

inlinestatic

Used to inject config into a node, even if it doesn't have the proper constructor

Definition at line 347 of file tree_node.h.

◆ isBlackboardPointer()

bool BT::TreeNode::isBlackboardPointer	(	StringView	str,
		StringView *	stripped_pointer = `nullptr`
	)

static

Check a string and return true if it matches the pattern: {...}.

Definition at line 375 of file tree_node.cpp.

◆ isHalted()

bool BT::TreeNode::isHalted ( ) const

Definition at line 307 of file tree_node.cpp.

◆ modifyPortsRemapping()

void BT::TreeNode::modifyPortsRemapping ( const PortsRemapping & new_remapping )

protected

Definition at line 449 of file tree_node.cpp.

◆ name()

const std::string & BT::TreeNode::name ( ) const

Name of the instance, not the type.

Definition at line 302 of file tree_node.cpp.

◆ operator=() [1/2]

TreeNode& BT::TreeNode::operator= ( const TreeNode & other )

delete

◆ operator=() [2/2]

TreeNode & BT::TreeNode::operator= ( TreeNode && other )

noexcept

Definition at line 62 of file tree_node.cpp.

◆ parseString()

template<typename T >

T BT::TreeNode::parseString ( const std::string & str ) const

protected

Definition at line 418 of file tree_node.h.

◆ postConditionsScripts()

TreeNode::PostScripts & BT::TreeNode::postConditionsScripts ( )

protected

Definition at line 188 of file tree_node.cpp.

◆ preConditionsScripts()

TreeNode::PreScripts & BT::TreeNode::preConditionsScripts ( )

protected

Definition at line 183 of file tree_node.cpp.

◆ registrationName()

const std::string & BT::TreeNode::registrationName ( ) const

registrationName is the ID used by BehaviorTreeFactory to create an instance.

Definition at line 346 of file tree_node.cpp.

◆ requiresWakeUp()

bool BT::TreeNode::requiresWakeUp ( ) const

Definition at line 434 of file tree_node.cpp.

◆ resetStatus()

void BT::TreeNode::resetStatus ( )

protected

Set the status to IDLE.

Definition at line 268 of file tree_node.cpp.

◆ setOutput()

template<typename T >

Result BT::TreeNode::setOutput	(	const std::string &	key,
		const T &	value
	)

inline

setOutput modifies the content of an Output port

Parameters

key	the name of the port.
value	new value

Returns: valid Result, if succesful.

Definition at line 558 of file tree_node.h.

◆ setPostTickFunction()

void BT::TreeNode::setPostTickFunction ( PostTickCallback callback )

This method attaches to the TreeNode a callback with signature:

NodeStatus myCallback(TreeNode& node, NodeStatus status)

This callback is executed AFTER the tick() and, if it returns SUCCESS or FAILURE, the value returned by the actual tick() is overriden with this one.

Definition at line 324 of file tree_node.cpp.

◆ setPreTickFunction()

void BT::TreeNode::setPreTickFunction ( PreTickCallback callback )

This method attaches to the TreeNode a callback with signature:

 NodeStatus callback(TreeNode& node)

This callback is executed BEFORE the tick() and, if it returns SUCCESS or FAILURE, the actual tick() will NOT be executed and this result will be returned instead.

This is useful to inject a "dummy" implementation of the TreeNode at run-time

Definition at line 318 of file tree_node.cpp.

◆ setRegistrationID()

void BT::TreeNode::setRegistrationID ( StringView ID )

protected

Definition at line 439 of file tree_node.cpp.

◆ setStatus()

void BT::TreeNode::setStatus ( NodeStatus new_status )

protected

setStatus changes the status of the node. it will throw if you try to change the status to IDLE, because your parent node should do that, not the user!

Definition at line 160 of file tree_node.cpp.

◆ setTickMonitorCallback()

void BT::TreeNode::setTickMonitorCallback ( TickMonitorCallback callback )

This method attaches to the TreeNode a callback with signature:

void myCallback(TreeNode& node, NodeStatus status, std::chrono::microseconds duration)

This callback is executed AFTER the tick() and will inform the user about its status and the execution time. Works only if the tick was not substituted by a pre-condition.

Definition at line 330 of file tree_node.cpp.

◆ setWakeUpInstance()

void BT::TreeNode::setWakeUpInstance ( std::shared_ptr< WakeUpSignal > instance )

protected

Definition at line 444 of file tree_node.cpp.

◆ status()

NodeStatus BT::TreeNode::status ( ) const

Definition at line 285 of file tree_node.cpp.

◆ stripBlackboardPointer()

StringView BT::TreeNode::stripBlackboardPointer ( StringView str )

static

Definition at line 401 of file tree_node.cpp.

◆ subscribeToStatusChange()

TreeNode::StatusChangeSubscriber BT::TreeNode::subscribeToStatusChange ( TreeNode::StatusChangeCallback callback )

subscribeToStatusChange is used to attach a callback to a status change. When StatusChangeSubscriber goes out of scope (it is a shared_ptr) the callback is unsubscribed automatically.

Parameters

callback The callback to be execute when status change.

Returns: the subscriber handle.

Definition at line 313 of file tree_node.cpp.

◆ tick()

virtual BT::NodeStatus BT::TreeNode::tick ( )

protectedpure virtual

Method to be implemented by the user.

Implemented in BT::StatefulActionNode, BT::SimpleActionNode, NodeWithDefaultNullptr, PrintToConsole, NodeWithDefaultStrings, Assert, NodeWithDefaultPoints, SetAny, GetAny, ActionWithMetadata, ComparisonNode, SampleNode595, DefaultTestAction, NaughtyNav2Node, SimpleOutput, ModifyPose, ActionVectorStringIn, ActionVectorDoubleIn, ReadInConstructor, IllegalPorts, CoroTestNode, IsHealthOk, NodeOutPorts, PrintEnum, NodeInPorts, FollowPath, BT::QueueSize< T >, ComputePathToPose, BackUpAndSpin, IsStuck, UseWaypoint, BT::ParallelNode, Action_B, BT::SubTreeNode, BT::TimeoutNode, PrintTarget, BT::SwitchNode< NUM_CASES >, BT::SimpleDecoratorNode, BT::RetryNode, NodeWithDefaultPoints, BT::PopFromQueue< T >, BT::SimpleConditionNode, BT::ParallelAllNode, BT::DelayNode, BT::RepeatNode, PrintNumber, DummyNodes::SaySomething, BT::LoopNode< T >, ThinkWhatToSay, BT::SetBlackboardNode, PrintNumber, CopyPorts, BT::RunOnceNode, BT::SequenceNode, CalculateGoal, BT::SequenceWithMemory, BT::FallbackNode, BT::IfThenElseNode, BT::ReactiveFallback, BT::ReactiveSequence, BT::EntryUpdatedDecorator, BT::AsyncActionTest, Action_A, BT::ManualSelectorNode, BT::WhileDoElseNode, BT::ScriptCondition, BT::EntryUpdatedAction, DummyNodes::ApproachObject, SimpleCoroAction, BT::PreconditionNode, SayRuntimePort, UpdatePosition, BT::ScriptNode, BT::ConsumeQueue< T >, BT::UnsetBlackboardNode, ActionEnum, BT::InverterNode, BT::KeepRunningUntilFailureNode, BT::AlwaysFailureNode, BT::AlwaysSuccessNode, BT::ForceFailureNode, BT::ForceSuccessNode, SetTask, GenerateWaypoints, ThinkRuntimePort, BT::test::SimpleCondition, FastAction, PushIntoVector, NodeWithPorts, BT::ConditionTestNode, BT::SyncActionTest, PrintVector, BB_TypedTestNode, and BB_TestNode.

◆ type()

virtual NodeType BT::TreeNode::type ( ) const

pure virtual

Implemented in BT::SubTreeNode, BT::ControlNode, BT::ActionNodeBase, BT::ConditionNode, and BT::DecoratorNode.

◆ UID()

uint16_t BT::TreeNode::UID ( ) const

The unique identifier of this instance of treeNode. It is assigneld by the factory

Definition at line 336 of file tree_node.cpp.

◆ waitValidStatus()

NodeStatus BT::TreeNode::waitValidStatus ( )

Blocking function that will sleep until the setStatus() is called with either RUNNING, FAILURE or SUCCESS.

Definition at line 291 of file tree_node.cpp.

Friends And Related Function Documentation

◆ BehaviorTreeFactory

friend class BehaviorTreeFactory

friend

Definition at line 367 of file tree_node.h.

◆ ControlNode

friend class ControlNode

friend

Definition at line 369 of file tree_node.h.

◆ DecoratorNode

friend class DecoratorNode

friend

Definition at line 368 of file tree_node.h.

◆ Tree

friend class Tree

friend

Definition at line 370 of file tree_node.h.

Member Data Documentation

◆ _p

std::unique_ptr<PImpl> BT::TreeNode::_p

private

Definition at line 404 of file tree_node.h.

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

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Types

Protected Member Functions

Private Member Functions

Private Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ PostScripts

◆ PostTickCallback

◆ PreScripts

◆ PreTickCallback

◆ Ptr

◆ StatusChangeCallback

◆ StatusChangeSignal

◆ StatusChangeSubscriber

◆ TickMonitorCallback

Constructor & Destructor Documentation

◆ TreeNode() [1/3]

◆ TreeNode() [2/3]

◆ TreeNode() [3/3]

◆ ~TreeNode()

Member Function Documentation

◆ checkPostConditions()

◆ checkPreConditions()

◆ config() [1/2]

◆ config() [2/2]

◆ emitWakeUpSignal()

◆ executeTick()

◆ fullPath()

◆ getInput() [1/2]

◆ getInput() [2/2]

◆ getInputStamped() [1/2]

◆ getInputStamped() [2/2]

◆ getLockedPortContent()

◆ getRawPortValue()

◆ getRemappedKey()

◆ halt()

◆ haltNode()

◆ Instantiate()

◆ isBlackboardPointer()

◆ isHalted()

◆ modifyPortsRemapping()

◆ name()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ parseString()

◆ postConditionsScripts()

◆ preConditionsScripts()

◆ registrationName()

◆ requiresWakeUp()

◆ resetStatus()

◆ setOutput()

◆ setPostTickFunction()

◆ setPreTickFunction()

◆ setRegistrationID()

◆ setStatus()

◆ setTickMonitorCallback()

◆ setWakeUpInstance()

◆ status()

◆ stripBlackboardPointer()

◆ subscribeToStatusChange()

◆ tick()

◆ type()

◆ UID()

◆ waitValidStatus()

Friends And Related Function Documentation

◆ BehaviorTreeFactory

◆ ControlNode

◆ DecoratorNode

◆ Tree

Member Data Documentation

◆ _p