AssetMetaDataInterface Class Reference

#include <assets.h>

Inheritance diagram for AssetMetaDataInterface:

Detailed Description

AssetMetaData allows to query the meta data of an asset. It is returned by AssetDescriptionInterface::GetMetaData. The methods of this interface are thread-safe, but the meta data of an asset may be changed concurrently, so the returned values may differ from call to call even when the calling thread made no modification inbetween.

You can't modify the meta data of an asset through this interface, you have to use AssetDescriptionInterface::StoreMetaData instead.

Public Types
enum	KIND {   NONE,   READ_ONLY,   PERSISTENT,   VERSION,   DERIVED,   USER }

Public Member Functions
enum maxon::AssetMetaDataInterface::KIND	MAXON_ENUM_FLAGS_CLASS (KIND)
MAXON_METHOD Result< BaseArray< Tuple< InternedId, KIND > > >	GetExistingEntries () const
MAXON_METHOD Result< Data >	Get (const InternedId &metaId) const
template<typename T >
MAXON_FUNCTION Result< typename T::ValueType >	Get (const T &attr, const typename T::ValueType &defaultValue=NullValue< const typename T::ValueType & >()) const
template<typename ATTR >
MAXON_FUNCTION Result< Opt< typename ATTR::ValueType > >	Get () const
MAXON_METHOD Int	GetTimeStamp (const InternedId &metaId) const

Private Member Functions
	MAXON_INTERFACE (AssetMetaDataInterface, MAXON_REFERENCE_CONST, "net.maxon.interface.assetmetadata")

Static Private Member Functions
static const MAXON_METHOD AssetMetaDataInterface *	NullValuePtr ()

Member Enumeration Documentation

KIND

enum KIND

strong

This enum defines flags for the kind of a meta data entry.

Enumerator
NONE	No flag set.
READ_ONLY	The meta data is read-only, for example the AssetTimeStamp.
PERSISTENT	The meta data is persistent.
VERSION	The meta data is tied to the version so that it isn't copied to a new version, for example the AssetVersionTag.
DERIVED	The meta data is derived from the asset and other meta data.
USER	The meta data should be stored in user folder.

Member Function Documentation

MAXON_INTERFACE()

MAXON_INTERFACE ( AssetMetaDataInterface  , MAXON_REFERENCE_CONST  , "net.maxon.interface.assetmetadata"    )

private

MAXON_ENUM_FLAGS_CLASS()

enum maxon::AssetMetaDataInterface::KIND MAXON_ENUM_FLAGS_CLASS

(

KIND

)

GetExistingEntries()

MAXON_METHOD Result<BaseArray<Tuple<InternedId, KIND> > > GetExistingEntries

(

)

const

Returns an array with the current set of meta data entries.

Returns

The current set of meta data entries given by the meta data attribute id and kind.

Note

The returned value may differ from call to call because another thread could have modified the meta data inbetween.

Get() [1/3]

MAXON_METHOD Result<Data> Get

(

const InternedId &

metaId

)

const

Returns the current value of the meta data entry for the meta data attribute #metaId.

Parameters

[in]

metaId

The identifier of the meta data attribute.

Returns

The current value for the attribute, or an empty Data if there is no entry. An error is returned if there is an entry, but loading the entry value fails.

Note

The returned value may differ from call to call because another thread could have modified the meta data inbetween.

Get() [2/3]

MAXON_FUNCTION Result<typename T::ValueType> Get	(	const T &	attr,
		const typename T::ValueType &	defaultValue = NullValue<const typename T::ValueType&>()
	)		const

Returns the current value of the meta data entry for the meta data attribute #attr.

Parameters

[in]	attr	The attribute for which the value shall be returned (has to be declared with MAXON_ATTRIBUTE).
[in]	defaultValue	The default value to use when there is no entry (a null value by default).

Returns

The current value for the id, or the defaultValue if there is no entry. An error is returned if there is an entry, but loading the entry value fails.

Note

The returned value may differ from call to call because another thread could have modified the meta data inbetween.

Get() [3/3]

MAXON_FUNCTION Result<Opt<typename ATTR::ValueType> > Get

(

)

const

Returns the current value of the meta data entry for the meta data attribute ATTR.

Template Parameters

ATTR	The attribute for which the value shall be returned (has to be declared with MAXON_ATTRIBUTE).

Returns

The current value for the id, or an empty Opt if there is no entry. An error is returned if there is an entry, but loading the entry value fails.

Note

The returned value may differ from call to call because another thread could have modified the meta data inbetween.

GetTimeStamp()

MAXON_METHOD Int GetTimeStamp

(

const InternedId &

metaId

)

const

Returns the time stamp for the meta data attribute #metaId. The time stamp is increased each time the value changes.

Parameters

[in]

metaId

The identifier of the meta data attribute.

Returns

The time stamp for the attribute, or 0 if there is no entry for the attribute.

Note

The returned value may differ from call to call because another thread could have modified the meta data inbetween.

NullValuePtr()

static const MAXON_METHOD AssetMetaDataInterface* NullValuePtr ( )

staticprivate