PdCom::Subscription Class Reference

PdCom Subscription interface. More...

#include <Subscription.h>

Inheritance diagram for PdCom::Subscription:

Public Types
enum	State { Invalid = 0, Pending, Active }

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...
Variable	getVariable () const
	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...
Process *	getProcess () const
	Get the assigned Process. More...
std::string	getPath () const
	Get the path of the subscribed variable. More...
Public Member Functions inherited from PdCom::DataDeserializer< Subscription >
std::enable_if<!std::is_arithmetic< T >::value, void >::type	getValue (T &dest, size_t offset=0) const
	Copy the values into a custom buffer. More...
std::enable_if< std::is_arithmetic< T >::value, void >::type	getValue (T &dest, size_t offset=0) const
	Copy the values into a custom buffer. More...
void	getValue (T(&dest)[M][N]) const
void	getValue (T(&dest)[N], size_t offset=0) const
T	getValue () const

Detailed Description

PdCom Subscription interface.

This class represents a subscription to a variable. It is updated either on a periodic base, on an external event (e.g. the value has changed) or as requested with poll(). The type of transmission can be selected by creating an appropriate Subscriber object.

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.

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.
selector	Select parts of multi-dimensional variables.

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.
selector	Select parts of multi-dimensional variables.

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.

getPath()

std::string PdCom::Subscription::getPath

(

)

const

Get the path of the subscribed variable.

This also works in Pending and Invalid state.

Returns

Path of the subscribed variable.

getProcess()

Process* PdCom::Subscription::getProcess

(

)

const

Get the assigned Process.

Returns

The Process.

getState()

State PdCom::Subscription::getState ( ) const

inlinenoexcept

Get the current state.

Returns

The state.

Examples:

advanced_example.cpp.

getVariable()

Variable PdCom::Subscription::getVariable

(

)

const

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:

• /builds/etherlab.org/pdcom/include/pdcom5/Subscription.h