Akonadi::Attribute Class Referenceabstract

#include <attribute.h>

Inheritance diagram for Akonadi::Attribute:

Public Types

typedef QList< Attribute * > List

Public Member Functions

virtual ~Attribute ()
virtual Attributeclone () const =0
virtual void deserialize (const QByteArray &data)=0
virtual QByteArray serialized () const =0
virtual QByteArray type () const =0

Protected Member Functions

 Attribute (const Attribute &)=default

Detailed Description

Provides interface for custom attributes for Entity.

This class is an interface for custom attributes, that can be stored in an entity. Attributes should be meta data, e.g. ACLs, quotas etc. that are not part of the entities' data itself.

Note that attributes are per user, i.e. when an attribute is added to an entity, it only applies to the current user.

To provide custom attributes, you have to subclass from this interface and reimplement the pure virtual methods.

class SecrecyAttribute : public Akonadi::Attribute
enum Secrecy
SecrecyAttribute( Secrecy secrecy = Public )
: mSecrecy( secrecy )
void setSecrecy( Secrecy secrecy )
mSecrecy = secrecy;
Secrecy secrecy() const
return mSecrecy;
virtual QByteArray type() const
return "secrecy";
virtual Attribute* clone() const
return new SecrecyAttribute( mSecrecy );
virtual QByteArray serialized() const
switch ( mSecrecy ) {
case Public: return "public"; break;
case Private: return "private"; break;
case Confidential: return "confidential"; break;
virtual void deserialize( const QByteArray &data )
if ( data == "public" )
mSecrecy = Public;
else if ( data == "private" )
mSecrecy = Private;
else if ( data == "confidential" )
mSecrecy = Confidential;

Additionally, you need to register your attribute with Akonadi::AttributeFactory for automatic deserialization during retrieving of collections or items:


Third party attributes need to be registered once by each application that uses them. So the above snippet needs to be in the resource that adds the attribute, and each application that uses the resource. This may be simplified in the future.

The custom attributes can be used in the following way:

Akonadi::Item item( "text/directory" );
SecrecyAttribute* attr = item.attribute<SecrecyAttribute>( Item::AddIfMissing );
attr->setSecrecy( SecrecyAttribute::Confidential );


Akonadi::Item item = ...
if ( item.hasAttribute<SecrecyAttribute>() ) {
SecrecyAttribute *attr = item.attribute<SecrecyAttribute>();
SecrecyAttribute::Secrecy secrecy = attr->secrecy();
Volker Krause vkrau[email protected][email protected][email protected]de.or[email protected]g

Definition at line 126 of file attribute.h.

Member Typedef Documentation

Describes a list of attributes.

Definition at line 132 of file attribute.h.

Constructor & Destructor Documentation

Attribute::~Attribute ( )

Destroys this attribute.

Member Function Documentation

virtual void Akonadi::Attribute::deserialize ( const QByteArray data)
pure virtual
virtual QByteArray Akonadi::Attribute::serialized ( ) const
pure virtual

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