xentara::model::ElementAttribute Class Reference

A reference to an attribute of a specific Xentara element. More...

#include <xentara/model/ElementAttribute.hpp>

Public Member Functions
	ElementAttribute ()=default
	Constructor for a null reference.
	ElementAttribute (const std::weak_ptr< Element > &element, std::weak_ptr< const Attribute > attribute)
	Constructor that sets the element and the attribute.
	operator bool () const noexcept
	Boolean operator.
auto	primaryKey () const -> std::string
	Gets the primary key of the attribute.
auto	readHandle () const -> data::ReadHandle
	Gets a read handle for the attribute.
auto	writeHandle () const -> data::WriteHandle
	Gets a write handle for the attribute.
auto	lockElement () const -> std::shared_ptr< Element >
	Obtains a shared pointer to the element.
auto	lockAttribute () const -> std::shared_ptr< const Attribute >
	Obtains a shared pointer to the attribute.
auto	lock () const -> std::pair< std::shared_ptr< Element >, std::shared_ptr< const Attribute > >
	Obtains a shared pointer to both the element and the attribute.

Detailed Description

A reference to an attribute of a specific Xentara element.

This is a convenience class that contains a weak reference to an element, and a weak reference to an attribute.

See also

Attribute

Constructor & Destructor Documentation

ElementAttribute() [1/2]

xentara::model::ElementAttribute::ElementAttribute ( )

default

Constructor for a null reference.

This constructor contstruct a null object that does not contain a reference to any elements or attributes. You must assign avalid object to this object before using it.

ElementAttribute() [2/2]

xentara::model::ElementAttribute::ElementAttribute	(	const std::weak_ptr< Element > &	element,
		std::weak_ptr< const Attribute >	attribute
	)

Constructor that sets the element and the attribute.

Constructs a reference to a specific attribute of a specific element.

Parameters

element	The element. This can be a null pointer if and only if attribute is also a null pointer, in which case a null reference is created, and this constructor is equalivalent to the default constructor.
attribute	The attribute. This can be a null pointer if and only if element is also a null pointer, in which case a null reference is created, and this constructor is equalivalent to the default constructor.

Member Function Documentation

lock()

auto xentara::model::ElementAttribute::lock

(

)

const -> std::pair<std::shared_ptr<Element>, std::shared_ptr<const Attribute>>

Obtains a shared pointer to both the element and the attribute.

Returns

A shared pointer to the element together with a shared pointer to the attribute. nullptr is returned for either pointer, if the corresponding object has been deleted. For a null (default constructed) reference, { nullptr, nullptr } is returned.

lockAttribute()

auto xentara::model::ElementAttribute::lockAttribute

(

)

const -> std::shared_ptr<const Attribute>

Obtains a shared pointer to the attribute.

Returns

A shared pointer to the attribute, or nullptr if the attribute has been deleted. nullptr is also returned for a null (default constructed) reference.

lockElement()

auto xentara::model::ElementAttribute::lockElement

(

)

const -> std::shared_ptr<Element>

Obtains a shared pointer to the element.

Returns

A shared pointer to the element, or nullptr if the element has been deleted. nullptr is also returned for a null (default constructed) reference.

operator bool()

xentara::model::ElementAttribute::operator bool ( ) const

explicitnoexcept

Boolean operator.

This operator checks whether the object is not a null reference.

Returns

Returns true if the object contains a reference to an attribute, or false if the object is a null (default constructed) reference.

primaryKey()

auto xentara::model::ElementAttribute::primaryKey

(

)

const -> std::string

Gets the primary key of the attribute.

Returns

The primary key of the attribute, in UTF-8 encoding, or an empty string for a null (default constructed) reference.

readHandle()

auto xentara::model::ElementAttribute::readHandle

(

)

const -> data::ReadHandle

Gets a read handle for the attribute.

Returns

A read handle for the attrubute, or a default constructed read handle for a null (default constructed) reference.

writeHandle()

auto xentara::model::ElementAttribute::writeHandle

(

)

const -> data::WriteHandle

Gets a write handle for the attribute.

Returns

A write handle for the attrubute, or a default constructed write handle for a null (default constructed) reference.