glo::TOndemand< T > Class Template Reference

A reference (as attribute) of a persistent object to another persistent object in the database. More...

#include <GloTOndemand.h>

Inheritance diagram for glo::TOndemand< T >:

Collaboration diagram for glo::TOndemand< T >:

Public Member Functions
	TOndemand ()
	TOndemand (const ObjID &rObjID)
	TOndemand (Base &rBase)
	TOndemand (unsigned long ulDatabaseID)
	TOndemand (const ObjID &rObjID, Base &rBase)
	TOndemand (const ObjID &rObjID, unsigned long ulDatabaseID)
	TOndemand (const TOndemand &rT)
virtual	~TOndemand ()
int	get (T *&prObj)
int	get (std::shared_ptr< T > &rRetVal)
virtual int	setReference (const ObjID &rObjID) override
int	set (const T *rObj)
	Adopts the object ID of the passed object as reference.
int	set (const T &rObj)
	Adopts the object ID of the passed object as reference.
int	set (const std::shared_ptr< T > &rObj)
	Adopts the object ID of the passed object as reference.
TOndemand< T > &	operator= (const TOndemand &rT)
	Assignment operator.
bool	operator== (const TOndemand &rT) const
	Comparison operator.
bool	operator!= (const TOndemand &rT) const
	Comparison operator.
Public Member Functions inherited from glo::Reference
	Reference ()
	Reference (const ObjID &rObjID)
	Reference (Base &rBase)
	Reference (unsigned long ulDatabaseID)
	Reference (const ObjID &rObjID, Base &rBase)
	Reference (const ObjID &rObjID, unsigned long ulDatabaseID)
	Reference (const Reference &rT)
virtual	~Reference ()
virtual int	setBase (Base *pBase) override
virtual Base *	getBase () const override
virtual int	getTypeAsString (std::string &rsTypeName) override
bool	isNULL () const
void	setNULL ()
ObjID	getObjID () const
const ObjID *	getObjIDAsPointer () const
int	setReference (const BasePersistent *pObj)
int	setReference (const BasePersistent &rObj)
int	getReference (BasePersistent *&prRetVal)
int	getReference (std::shared_ptr< BasePersistent > &rspRetVal)
virtual int	deleteInBase (EnDeepMode eDeepMode=DM_SHALLOW)
virtual int	lock (EnLockMode eLockMode=LK_DELETEvWRITE, EnDeepMode eDeepMode=DM_SHALLOW) const
virtual int	lock (const LockSpecification &rLockSpecification) const
virtual int	unlock (EnLockMode eLockMode=LK_DELETEvWRITE, EnDeepMode eDeepMode=DM_SHALLOW) const
virtual int	unlock (const LockSpecification &rLockSpecification) const
virtual int	isLocked (EnLockMode eLockMode=LK_DELETEvWRITE, EnDeepMode eDeepMode=DM_SHALLOW) const
virtual int	isLocked (const LockSpecification &rLockSpecification) const
virtual int	isPossible (bool bRead, bool bWrite, bool bDelete, EnDeepMode eDeepMode=DM_SHALLOW) const
virtual int	isPossible (const LockPossibleSpecification &rLockPossibleSpec, EnDeepMode eDeepMode=DM_SHALLOW) const
virtual int	setWatch (TdWatchNotifyMode ulWatchMode, EnDeepMode eDeepMode, CallBack *pCallBack=0) const
virtual int	setWatch (const WatchSpecification &rWatchSpec) const
virtual int	unsetWatch (TdWatchNotifyMode ulWatchMode, EnDeepMode eDeepMode, CallBack *pCallBack) const
virtual int	unsetWatch (const WatchSpecification &rWatchSpec) const
Reference &	operator= (const Reference &rT)
bool	operator== (const Reference &rT) const
	Comparison operator.
bool	operator!= (const Reference &rT) const
	Comparison operator.
Public Member Functions inherited from glo::CallBack
	CallBack ()
virtual	~CallBack ()
virtual void	notify (NotifyNote &rNote)
CallBack &	operator= (const CallBack &rT)
bool	operator== (const CallBack &rT) const
	Comparison operator, all attributes are compared.
bool	operator!= (const CallBack &rT) const
	Comparison operator, all attributes are compared.

Static Public Member Functions
static unsigned long	getStaticGloClassID ()

Additional Inherited Members
Public Attributes inherited from glo::CallBack
std::string	m_strDebugInfo
Protected Member Functions inherited from glo::CallBack
	CallBack (const CallBack &rT)
void	init ()
void	deinit ()

Detailed Description

template<class T>
class glo::TOndemand< T >

A reference (as attribute) of a persistent object to another persistent object in the database.

In contrast to a pointer to a persistent object (where the referenced object is loaded with the referencing object), TOndemand is a reference to a persistent object via the object ID; it is not loaded with the referencing object from the database, but can be 'reloaded' if needed.

It makes sense to use TOndemand whenever an object references a 'large' object that is not necessarily available in memory.

E.g. in an image management system an image object could contain textual information, a thumpnail and a 'large' image. For some views it may not be useful to get the 'large' image from the database for every display due to speed reasons. In this case a reference via a TOndemand would be useful.

If objects in one object database should reference objects in another object database, this is only possible with glo::TOndemand.

Copyright

© 2010 Helmut Jakoby

Author

Helmut Jakoby

Constructor & Destructor Documentation

TOndemand() [1/7]

template<class T>

glo::TOndemand< T >::TOndemand

(

)

Standard constructor.

TOndemand() [2/7]

template<class T>

glo::TOndemand< T >::TOndemand

(

const ObjID &

rObjID

)

Constructor with parameter passing.

Parameters

[in]

rObjID

The object ID of the object to be referenced can be specified during creation.

TOndemand() [3/7]

template<class T>

glo::TOndemand< T >::TOndemand

(

Base &

rBase

)

Constructor with parameter passing.

Parameters

[in]

rBase

The authoritative database can be specified during the creation.

TOndemand() [4/7]

template<class T>

glo::TOndemand< T >::TOndemand

(

unsigned long

ulDatabaseID

)

Constructor with parameter passing.

Parameters

[in]

ulDatabaseID

The authoritative database id can be specified during the creation.

TOndemand() [5/7]

template<class T>

glo::TOndemand< T >::TOndemand	(	const ObjID &	rObjID,
		Base &	rBase )

Constructor with parameter passing.

Parameters

[in]	rObjID	The object ID of the object to be referenced and...
[in]	rBase	...the relevant database can be specified during creation.

TOndemand() [6/7]

template<class T>

glo::TOndemand< T >::TOndemand	(	const ObjID &	rObjID,
		unsigned long	ulDatabaseID )

Constructor with parameter passing.

Parameters

[in]	rObjID	The object ID of the object to be referenced and...
[in]	ulDatabaseID	...the relevant database id can be specified during creation.

TOndemand() [7/7]

template<class T>

glo::TOndemand< T >::TOndemand

(

const TOndemand< T > &

rT

)

Copy constructor.

Parameters

[in]

rT

The data is copied from this object.

~TOndemand()

template<class T>

glo::TOndemand< T >::~TOndemand ( )

virtual

Destructor

Member Function Documentation

get() [1/2]

template<class T>

int glo::TOndemand< T >::get

(

std::shared_ptr< T > &

rRetVal

)

Returns the referenced object from the database (or from memory if already loaded) in a std::shared_ptr.

Parameters

[in,out]

rRetVal

The referenced object in a std::shared_ptr.

Returns

A return < 0 indicates an error.
If a referenced object does not exist in the database, the error glo::ERR_NO_INDEX is returned.

get() [2/2]

template<class T>

int glo::TOndemand< T >::get

(

T *&

prObj

)

Returns the referenced object from the database (or from memory if already loaded).

Parameters

[in,out]

prObj

The pointer reference to the referenced object.

Returns

A return < 0 indicates an error.
If a referenced object does not exist in the database, the error glo::ERR_NO_INDEX is returned.

Attention

The returned object must be removed from memory by the calling instance using BasePersistent::forget().

Note

It is recommended, if possible, to consider using std::shared_ptr and to use the method get(std::shared_ptr<T>&).

Es wird empfohlen, wenn möglich, die Verwendung von std::shared_ptr in Betracht zu ziehen und die Methode get(std::shared_ptr<T>&) zu nutzen.

getStaticGloClassID()

template<class T>

static unsigned long glo::TOndemand< T >::getStaticGloClassID ( )

inlinestatic

Returns the template class ID.

Returns

The class ID

operator!=()

template<class T>

bool glo::TOndemand< T >::operator!=

(

const TOndemand< T > &

rT

)

const

Comparison operator.

Parameters

[in]

rT

The object to be compared with this one.

operator=()

template<class T>

TOndemand< T > & glo::TOndemand< T >::operator=

(

const TOndemand< T > &

rT

)

Assignment operator.

Parameters

[in]

rT

The data is transferred from this object.

operator==()

template<class T>

bool glo::TOndemand< T >::operator==

(

const TOndemand< T > &

rT

)

const

Comparison operator.

Parameters

[in]

rT

The object to be compared with this one.

set() [1/3]

template<class T>

int glo::TOndemand< T >::set

(

const std::shared_ptr< T > &

rObj

)

Adopts the object ID of the passed object as reference.

Parameters

[in]

pObj

The pointer to the object to be referenced.

Returns

A return value < 0 indicates an error.

Note

Both objects, this one and the one to be referenced must be logged on to the same database.

set() [2/3]

template<class T>

int glo::TOndemand< T >::set

(

const T &

rObj

)

Adopts the object ID of the passed object as reference.

Parameters

[in]

pObj

The pointer to the object to be referenced.

Returns

A return value < 0 indicates an error.

Note

Both objects, this one and the one to be referenced must be logged on to the same database.

set() [3/3]

template<class T>

int glo::TOndemand< T >::set

(

const T *

rObj

)

Adopts the object ID of the passed object as reference.

Parameters

[in]

pObj

The pointer to the object to be referenced.

Returns

A return value < 0 indicates an error.

Note

Both objects, this one and the one to be referenced must be logged on to the same database.

setReference()

template<class T>

int glo::TOndemand< T >::setReference ( const ObjID & rObjID )

overridevirtual

Adopts the object ID as reference.

Parameters

[in]

rObjID

The object ID to be referenced.

Note

Both objects, this one and the one to be referenced must be logged on to the same database.

Reimplemented from glo::Reference.

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

• GloTOndemand.h