PdCom::Subscription Class Reference

PdCom Subscription interface. More...

#include <Subscription.h>

Classes
struct	invalid_subscription

Public Types
enum	State { Invalid = 0, Pending, Active }
enum	SubscriberState { SubscriberState::FullyConstructed, SubscriberState::UnderConstruction }

Public Member Functions
	Subscription ()=default
	Default constructor for an empty subscription.
	Subscription (Subscription &&) noexcept
Subscription &	operator= (Subscription &&) noexcept
	Subscription (Subscriber &subscriber, const Variable &variable, const Selector &selector={})
	Constructor for a known variable. More...
	Subscription (Subscriber &subscriber, Process &process, const std::string &path, const Selector &selector={})
	Constructor for an unknown variable. More...
void	poll ()
	Poll values from the server. More...
const void *	getData () const
	Get the data Pointer. More...
template<typename T >
std::enable_if<!std::is_arithmetic< T >::value, void >::type	getValue (T &dest) const
	Copy the values into a custom buffer. More...
template<typename T >
std::enable_if< std::is_arithmetic< T >::value, void >::type	getValue (T &dest) const
	Copy the values into a custom buffer. More...
Variable	getVariable () const noexcept
	Access the subscribed variable. More...
void	print (std::ostream &os, char delimiter) const
	Print the value(s). More...
bool	empty () const noexcept
	Check whether the subscription is default-constructed. More...
State	getState () const noexcept
	Get the current state. More...

Detailed Description

PdCom Subscription interface.

This class represents a subscription to a variable. It is updated eighter on a periodic base, on an external event (e.g. the value has changed) or as requested with poll().

To cancel a subscription, you have to delete the corresponding subscription instance.

Calling getState() is always allowed, the other member functions need the subscription to be Active.

Examples:

advanced_example.cpp.

Member Enumeration Documentation

SubscriberState

enum PdCom::Subscription::SubscriberState

strong

Enumerator
FullyConstructed	Allow callbacks.
UnderConstruction	Suppress callbacks.

Constructor & Destructor Documentation

Subscription() [1/2]

PdCom::Subscription::Subscription	(	Subscriber &	subscriber,
		const Variable &	variable,
		const Selector &	selector = {}
	)

Constructor for a known variable.

Parameters

subscriber	Subscriber which will recieve the status updates.
variable	The variable to subscribe.
substate	(Dis)allow immediate callbacks.

Exceptions

invalid_subscription

Subscription is already known to be invalid.

Subscription() [2/2]

PdCom::Subscription::Subscription	(	Subscriber &	subscriber,
		Process &	process,
		const std::string &	path,
		const Selector &	selector = {}
	)

Constructor for an unknown variable.

Parameters

subscriber	Subscriber which will recieve the status updates.
process	The process.
path	Path of the variable to subscribe.
substate	(Dis)allow immediate callbacks.

Exceptions

invalid_subscription

Subscription is already known to be invalid.

Member Function Documentation

empty()

bool PdCom::Subscription::empty ( ) const

inlinenoexcept

Check whether the subscription is default-constructed.

Returns

false The subscription is populated.

getData()

const void* PdCom::Subscription::getData

(

)

const

Get the data Pointer.

The subscription has to be Active.

Returns

Pointer to the internal storage.

getState()

State PdCom::Subscription::getState ( ) const

inlinenoexcept

Get the current state.

Returns

The state.

Examples:

advanced_example.cpp.

getValue() [1/2]

template<typename T >

std::enable_if<!std::is_arithmetic<T>::value, void>::type PdCom::Subscription::getValue ( T &  dest ) const

inline

Copy the values into a custom buffer.

Up to buf.size() values are converted into the type of the buffer. The subscription has to be Active.

Parameters

dest	Custom buffer.

getValue() [2/2]

template<typename T >

std::enable_if<std::is_arithmetic<T>::value, void>::type PdCom::Subscription::getValue ( T &  dest ) const

inline

Copy the values into a custom buffer.

The subscription has to be Active.

Parameters

dest	Custom buffer.

getVariable()

Variable PdCom::Subscription::getVariable ( ) const

noexcept

Access the subscribed variable.

The subscription must not be empty().

Returns

The subscribed variable.

poll()

void PdCom::Subscription::poll

(

)

Poll values from the server.

The subscription has to be Active.

print()

void PdCom::Subscription::print	(	std::ostream &	os,
		char	delimiter
	)		const

Print the value(s).

Parameters

os	Stream to print into.
delimiter	Delimiter which separates the values.

Examples:

advanced_example.cpp.

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

• /home/abuild/rpmbuild/BUILD/pdcom5-5.0alpha1.35.g0d31fd3/include/pdcom5/Subscription.h