IlsInvertedRelationList< TargetType, OriginType > Class Template Reference

Inverted relation list. More...

#include <ilserver/model.h>

Inheritance diagram for IlsInvertedRelationList< TargetType, OriginType >:

Classes
class	ConstIterator
	Const iterator. More...
class	Iterator
	Non const iterator. More...
class	Position
	This class is nested in the class template IlsInvertedRelationList. It sets an iterator to a given position. More...

Public Types
typedef Relations	Initial
	This class provides a list of origin objects when a relation is created. More...
typedef IlsInvertedRelationList< TargetType, OriginType >	Myself
	Myself is the type of the instantiated template class.

Public Member Functions
	IlsInvertedRelationList (TargetType &target, IlsActivity activity=IlsModel::GetDefaultActivity(), IlsCardinality mincard=0, IlsCardinality maxcard=ILS_UNLIMITED_MAXCARD, Initial &targets=(*new Initial()), IlsBoolean check_card=IlsTrue)
virtual IlsViewed *	getIdentifiedElement (const IlsString &id) const
	This virtual member function is used to retrieve an identified object from the relation. More...
virtual IlsBoolean	hasElement (IlsViewed &) const
	This virtual member function returns IlsTrue if the element is a target of the relation or IlsFalse otherwise.
Accessors
TargetType &	getTarget () const
	Returns the target of the relation.
OriginType *	operator[] (int i) const
	Returns the i-th list element.
OriginType *	getFirst () const
	Returns the first item of the list. More...
OriginType *	getLast () const
	Returns the last item of the list. More...
IlsBoolean	isIn (OriginType *e)
	Returns IlsTrue if the specified item belongs to the list.
Adding/Removing Objects
Myself &	cons (OriginType *newe)
	Adds the specified object to the list. More...
Myself &	operator<< (OriginType *newe)
	This insertion operator adds an object to the list. More...
Myself &	remove (OriginType *olde)
	Removes the specified object from the list. More...
Myself &	operator>> (OriginType *olde)
	This extraction operator removes an object from the list. More...
Myself &	clear ()
	Empties the list. More...
Notification
OriginType **	getAdded (int &)
	During a notification phase, this member function returns an array of pointers to the objects that have been added to the list since the last notification phase. More...
OriginType **	getRemoved (int &)
	During a notification phase, this member function returns an array of pointers to the objects that have been removed from the list since the last notification phase. More...
Public Member Functions inherited from IlsListRelation
unsigned int	getLength () const
	Returns the number of objects in the list.
IlsCardinality	getMaxCard () const
	Indicates the maximal cardinality of the list.
IlsCardinality	getMinCard () const
	Indicates the minimal cardinality of the list.
IlsBoolean	isLengthModified ()
	During a notification phase, this member function returns IlsTrue if the number of objects in the list has been modified since the last notification phase.
IlsBoolean	isModified ()
	During a notification phase, this member function returns IlsTrue if the list relation has been modified since the last notification phase, that is, if one or more items have been added to, or removed from, the list.

Static Public Member Functions
static Initial &	NewInitial ()
	Builds an empty list which is used by the constructor as the default value of the argument origins.

Detailed Description

template<class TargetType, class OriginType>
class IlsInvertedRelationList< TargetType, OriginType >

Inverted relation list.

Template Parameters

TargetType	Target class of the direct relation.
OriginType	Class that contains the direct relation.

Library: server

Rogue Wave Server lets you invert several relations by maintaining a list of back pointers to the origins of a set of relations. This list of pointers is declared as an instance of the class template IlsInvertedRelationList and maintained by means of the functions setContext() and unsetContext(). Modifying an inverted relation may trigger the recomputation of derived data members that depend on that relation.

The IlsInvertedRelationList template makes a forward declaration of the function IlsViewed* Ils2Viewed(OriginType*) and uses it in its implementation. This is to prevent the compiler from requiring visibility on the class OriginType when instantiating the inverted relation template. The implementation of the Ils2Viewed() function is expanded by the macro ILS_OBJECT_DECL() or its derivatives. If you do not want to use that macro because the type OriginType is not notified by views, you can define your own function in a source of your application that has visibility on the class OriginType, as follows:

Ils2Viewed* Ils2Viewed(TargetType* obj){return obj;} 

Related Pattern

Bridge

See also

IlsException, IlsDerived, IlsEntity, IlsInvertedRelationList::Initial, IlsInvertedRelationList::ConstIterator, IlsInvertedRelationList::Iterator, IlsInvertedRelationList::Position, IlsObject, IlsOwnsList, IlsUsesList, setContext(), unsetContext().

Member Typedef Documentation

Initial

template<class TargetType, class OriginType>

typedef Relations IlsInvertedRelationList< TargetType, OriginType >::Initial

This class provides a list of origin objects when a relation is created.

This list must contain at least as many items as specified for the minimal cardinality.

Constructor & Destructor Documentation

IlsInvertedRelationList()

template<class TargetType, class OriginType>

IlsInvertedRelationList< TargetType, OriginType >::IlsInvertedRelationList	(	TargetType &	target,
		IlsActivity	activity = IlsModel::GetDefaultActivity(),
		IlsCardinality	mincard = 0,
		IlsCardinality	maxcard = ILS_UNLIMITED_MAXCARD,
		Initial &	targets = (*new Initial()),
		IlsBoolean	check_card = IlsTrue
	)

This constructor takes the following arguments:

• A reference to the target object (that is, to the object in which the relation is declared).
• The argument activity specifies whether the relation is active or not. A relation is active if its modification sets off the recomputation of derived data members. The default value is the one returned by the static member function IlsModel::GetDefaultActivity(), which is ILS_INACTIVE by default.
• The minimal cardinality of the list: This argument is optional and defaults to zero.
• The maximal cardinality of the list. The maximal cardinality can be an unsigned integer, or can be indetermined. This argument is optional and defaults to ILS_UNLIMITED_MAXCARD.
• The argument targets is a list of objects. Its default value, NewInitial(), creates an empty list.
• The argument check_card specifies whether cardinalities should be checked at object construction.

Exceptions

IlsMinCardViolated	If the length of targets is less than the value assigned to mincard.
IlsMaxCardViolated	If the length of targets is greater than the value of maxcard.

Member Function Documentation

clear()

template<class TargetType, class OriginType>

Myself& IlsInvertedRelationList< TargetType, OriginType >::clear

(

)

Empties the list.

Exceptions

IlsMinCardViolated

If the minimal cardinality is different from zero. The number of items remaining in the list will be equal to the minimal cardinality specified.

cons()

template<class TargetType, class OriginType>

Myself& IlsInvertedRelationList< TargetType, OriginType >::cons

(

OriginType *

newe

)

Adds the specified object to the list.

Exceptions

IlsMaxCardViolated

If this function is called when the maximum cardinality has been reached.

getAdded()

template<class TargetType, class OriginType>

OriginType** IlsInvertedRelationList< TargetType, OriginType >::getAdded

(

int &

)

During a notification phase, this member function returns an array of pointers to the objects that have been added to the list since the last notification phase.

It returns an empty array if no object has been added to the list.

getFirst()

template<class TargetType, class OriginType>

OriginType* IlsInvertedRelationList< TargetType, OriginType >::getFirst

(

)

const

Returns the first item of the list.

Exceptions

IlsForbiddenOnEmptyList

If the list is empty.

getIdentifiedElement()

template<class TargetType, class OriginType>

virtual IlsViewed* IlsInvertedRelationList< TargetType, OriginType >::getIdentifiedElement ( const IlsString &  id ) const

virtual

This virtual member function is used to retrieve an identified object from the relation.

The member function IlsViewed::getKeyIdentifier() is used to retrieve the identifier of the relation element.

Note

On all subclasses of this class, the complexity of this method is always linear, in terms of the number of elements in the relation, even for set relations.

Reimplemented from IlsViewedRel.

getLast()

template<class TargetType, class OriginType>

OriginType* IlsInvertedRelationList< TargetType, OriginType >::getLast

(

)

const

Returns the last item of the list.

Exceptions

IlsForbiddenOnEmptyList

If the list is empty.

getRemoved()

template<class TargetType, class OriginType>

OriginType** IlsInvertedRelationList< TargetType, OriginType >::getRemoved

(

int &

)

During a notification phase, this member function returns an array of pointers to the objects that have been removed from the list since the last notification phase.

It returns an empty array if no object has been removed from the list.

operator<<()

template<class TargetType, class OriginType>

Myself& IlsInvertedRelationList< TargetType, OriginType >::operator<<

(

OriginType *

newe

)

This insertion operator adds an object to the list.

Exceptions

IlsMaxCardViolated

If this function is called when the maximum cardinality has been reached.

operator>>()

template<class TargetType, class OriginType>

Myself& IlsInvertedRelationList< TargetType, OriginType >::operator>>

(

OriginType *

olde

)

This extraction operator removes an object from the list.

Exceptions

IlsMinCardViolated	If this function is called when the minimal cardinality has been reached
IlsNotFound	If removing an object that does not belong to the list.

remove()

template<class TargetType, class OriginType>

Myself& IlsInvertedRelationList< TargetType, OriginType >::remove

(

OriginType *

olde

)

Removes the specified object from the list.

Exceptions

IlsMinCardViolated	If this function is called when the minimal cardinality has been reached
IlsNotFound	If removing an object that does not belong to the list.