Overview

A container for media metadata.

Metadata has a media type, an optional list of images, and a collection of metadata fields. Keys for common metadata fields are predefined as constants, but the application is free to define and use additional fields of its own.

The values of the predefined fields have predefined types. For example, a track number is an NSInteger and a creation date is an NSString containing an ISO-8601 representation of a date and time. Attempting to store a value of an incorrect type in a field will raise an NSInvalidArgumentException.

Note that the Cast protocol limits which metadata fields can be used for a given media type. When a MediaMetadata object is serialized to JSON for delivery to a Cast receiver, any predefined fields which are not supported for a given media type will not be included in the serialized form, but any application-defined fields will always be included. The complete list of predefined fields is as follows:

Field	Value Type	Valid Metadata Types
kGCKMetadataKeyCreationDate	NSDate	GCKMediaMetadataTypePhoto
kGCKMetadataKeyReleaseDate	NSDate	GCKMediaMetadataTypeGeneric, GCKMediaMetadataTypeMovie, GCKMediaMetadataTypeTVShow, GCKMediaMetadataTypeMusicTrack
kGCKMetadataKeyBroadcastDate	NSDate	GCKMediaMetadataTypeTVShow
kGCKMetadataKeyTitle	NSString	GCKMediaMetadataTypeGeneric, GCKMediaMetadataTypeMovie, GCKMediaMetadataTypeTVShow, GCKMediaMetadataTypeMusicTrack, GCKMediaMetadataTypePhoto
kGCKMetadataKeySubtitle	NSString	GCKMediaMetadataTypeGeneric, GCKMediaMetadataTypeMovie
kGCKMetadataKeyArtist	NSString	GCKMediaMetadataTypeGeneric, GCKMediaMetadataTypeMusicTrack, GCKMediaMetadataTypePhoto
kGCKMetadataKeyAlbumArtist	NSString	GCKMediaMetadataTypeMusicTrack
kGCKMetadataKeyAlbumTitle	NSString	GCKMediaMetadataTypeMusicTrack
kGCKMetadataKeyComposer	NSString	GCKMediaMetadataTypeMusicTrack
kGCKMetadataKeyDiscNumber	NSInteger	GCKMediaMetadataTypeMusicTrack
kGCKMetadataKeyTrackNumber	NSInteger	GCKMediaMetadataTypeMusicTrack
kGCKMetadataKeySeasonNumber	NSInteger	GCKMediaMetadataTypeTVShow
kGCKMetadataKeyEpisodeNumber	NSInteger	GCKMediaMetadataTypeTVShow
kGCKMetadataKeySeriesTitle	NSString	GCKMediaMetadataTypeTVShow
kGCKMetadataKeyStudio	NSString	GCKMediaMetadataTypeMovie
kGCKMetadataKeyWidth	NSInteger	GCKMediaMetadataTypePhoto
kGCKMetadataKeyHeight	NSInteger	GCKMediaMetadataTypePhoto
kGCKMetadataKeyLocationName	NSString	GCKMediaMetadataTypePhoto
kGCKMetadataKeyLocationLatitude	double	GCKMediaMetadataTypePhoto
kGCKMetadataKeyLocationLongitude	double	GCKMediaMetadataTypePhoto

Inherits NSObject, <NSCopying>, and <NSSecureCoding>.

Instance Method Summary
(instancetype)	- initWithMetadataType:
	Initializes a new, empty, MediaMetadata with the given media type. More...

(instancetype)	- init
	Initialize with the generic metadata type. More...

(GCKMediaMetadataType)	- metadataType
	The metadata type. More...

(NSArray *)	- images
	Gets the list of images. More...

(void)	- removeAllMediaImages
	Removes all the current images. More...

(void)	- addImage:
	Adds an image to the list of images. More...

(BOOL)	- containsKey:
	Tests if the object contains a field with the given key. More...

(NSArray< NSString * > *)	- allKeys
	Returns a set of keys for all fields that are present in the object. More...

(nullable id)	- objectForKey:
	Reads the value of a field. More...

(void)	- setString:forKey:
	Stores a value in a string field. More...

(nullable NSString *)	- stringForKey:
	Reads the value of a string field. More...

(void)	- setInteger:forKey:
	Stores a value in an integer field. More...

(NSInteger)	- integerForKey:
	Reads the value of an integer field. More...

(NSInteger)	- integerForKey:defaultValue:
	Reads the value of an integer field. More...

(void)	- setDouble:forKey:
	Stores a value in a double field. More...

(double)	- doubleForKey:
	Reads the value of a double field. More...

(double)	- doubleForKey:defaultValue:
	Reads the value of a double field. More...

(void)	- setDate:forKey:
	Stores a value in a date field as a restricted ISO-8601 representation of the date. More...

(nullable NSDate *)	- dateForKey:
	Reads the value of a date field from the restricted ISO-8601 representation of the date. More...

(nullable NSString *)	- dateAsStringForKey:
	Reads the value of a date field, as a string. More...

Public Attributes
NSString *const	kGCKMetadataKeyCreationDate
	String key: Creation date. More...

NSString *const	kGCKMetadataKeyReleaseDate
	String key: Release date. More...

NSString *const	kGCKMetadataKeyBroadcastDate
	String key: Broadcast date. More...

NSString *const	kGCKMetadataKeyTitle
	String key: Title. More...

NSString *const	kGCKMetadataKeySubtitle
	String key: Subtitle. More...

NSString *const	kGCKMetadataKeyArtist
	String key: Artist. More...

NSString *const	kGCKMetadataKeyAlbumArtist
	String key: Album artist. More...

NSString *const	kGCKMetadataKeyAlbumTitle
	String key: Album title. More...

NSString *const	kGCKMetadataKeyComposer
	String key: Composer. More...

NSString *const	kGCKMetadataKeyDiscNumber
	Integer key: Disc number. More...

NSString *const	kGCKMetadataKeyTrackNumber
	Integer key: Track number. More...

NSString *const	kGCKMetadataKeySeasonNumber
	Integer key: Season number. More...

NSString *const	kGCKMetadataKeyEpisodeNumber
	Integer key: Episode number. More...

NSString *const	kGCKMetadataKeySeriesTitle
	String key: Series title. More...

NSString *const	kGCKMetadataKeyStudio
	String key: Studio. More...

NSString *const	kGCKMetadataKeyWidth
	Integer key: Width. More...

NSString *const	kGCKMetadataKeyHeight
	Integer key: Height. More...

NSString *const	kGCKMetadataKeyLocationName
	String key: Location name. More...

NSString *const	kGCKMetadataKeyLocationLatitude
	Double key: Location latitude. More...

NSString *const	kGCKMetadataKeyLocationLongitude
	Double key: Location longitude. More...

NSString *const	kGCKMetadataKeyBookTitle
	String key: Book title. More...

NSString *const	kGCKMetadataKeyChapterNumber
	Integer key: Chapter number. More...

NSString *const	kGCKMetadataKeyChapterTitle
	String key: Chapter title. More...

NSString *const	kGCKMetadataKeySectionDuration
	Double key: Section Duration. More...

NSString *const	kGCKMetadataKeySectionStartTimeInMedia
	Double key: Section Start Time in Media. More...

NSString *const	kGCKMetadataKeySectionStartAbsoluteTime
	Double key: Section Absolute Start Time. More...

NSString *const	kGCKMetadataKeySectionStartTimeInContainer
	Double key: Section Start Time in Container. More...

NSString *const	kGCKMetadataKeyQueueItemID
	Double key: Queue Item ID. More...

Property Summary
GCKMediaMetadataType	metadataType
	The metadata type. More...

Method Detail

- (instancetype) initWithMetadataType: (GCKMediaMetadataType) metadataType

Initializes a new, empty, MediaMetadata with the given media type.

Designated initializer.

Parameters

metadataType The media type; one of the GCKMediaMetadataType constants, or a value greater than or equal to GCKMediaMetadataTypeUser for custom media types.

- (instancetype) init

Initialize with the generic metadata type.

- (GCKMediaMetadataType) metadataType

The metadata type.

- (NSArray *) images

Gets the list of images.

- (void) removeAllMediaImages

Removes all the current images.

- (void) addImage: (GCKImage *) image

Adds an image to the list of images.

Parameters

image The image to add.

- (BOOL) containsKey: (NSString *) key

Tests if the object contains a field with the given key.

Parameters

key The key.

Returns: YES if the field exists, NO otherwise.

- (NSArray<NSString *> *) allKeys

Returns a set of keys for all fields that are present in the object.

- (nullable id) objectForKey: (NSString *) key

Reads the value of a field.

Parameters

key	The key for the field.

Returns: The value of the field, or nil if the field has not been set.

- (void) setString:	(NSString *)	value
forKey:	(NSString *)	key

Stores a value in a string field.

Parameters

value	The new value for the field.
key	The key for the field.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not a string field.

- (nullable NSString *) stringForKey: (NSString *) key

Reads the value of a string field.

Parameters

key	The key for the field.

Returns: The value of the field, or nil if the field has not been set.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not a string field.

- (void) setInteger:	(NSInteger)	value
forKey:	(NSString *)	key

Stores a value in an integer field.

Parameters

value	The new value for the field.
key	The key for the field.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not an integer field.

- (NSInteger) integerForKey: (NSString *) key

Reads the value of an integer field.

Parameters

key	The key for the field.

Returns: The value of the field, or 0 if the field has not been set.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not an integer field.

- (NSInteger) integerForKey:	(NSString *)	key
defaultValue:	(NSInteger)	defaultValue

Reads the value of an integer field.

Parameters

key	The key for the field.
defaultValue	The value to return if the field has not been set.

Returns: The value of the field, or the given default value if the field has not been set.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not an integer field.

- (void) setDouble:	(double)	value
forKey:	(NSString *)	key

Stores a value in a double field.

Parameters

value	The new value for the field.
key	The key for the field.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not a double field.

- (double) doubleForKey: (NSString *) key

Reads the value of a double field.

Parameters

key	The key for the field.

Returns: The value of the field, or 0 if the field has not been set.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not a double field.

- (double) doubleForKey:	(NSString *)	key
defaultValue:	(double)	defaultValue

Reads the value of a double field.

Parameters

defaultValue	The value to return if the field has not been set.
key	The key for the field.

Returns: The value of the field, or the given default value if the field has not been set.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not a double field.

- (void) setDate:	(NSDate *)	date
forKey:	(NSString *)	key

Stores a value in a date field as a restricted ISO-8601 representation of the date.

Parameters

date	The new value for the field.
key	The key for the field.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not a date field.

- (nullable NSDate *) dateForKey: (NSString *) key

Reads the value of a date field from the restricted ISO-8601 representation of the date.

Parameters

key	The field name.

Returns: The date, or nil if this field has not been set.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not a date field.

- (nullable NSString *) dateAsStringForKey: (NSString *) key

Reads the value of a date field, as a string.

Parameters

key	The field name.

Returns: The date as a string containing the restricted ISO-8601 representation of the date, or nil if this field has not been set.

Exceptions

NSInvalidArgumentException if the key refers to a predefined field which is not a date field.

Member Data Documentation

- (NSString* const) kGCKMetadataKeyCreationDate

String key: Creation date.

The value is the date and/or time at which the media was created, in ISO-8601 format. For example, this could be the date and time at which a photograph was taken or a piece of music was recorded.

- (NSString* const) kGCKMetadataKeyReleaseDate

String key: Release date.

The value is the date and/or time at which the media was released, in ISO-8601 format. For example, this could be the date that a movie or music album was released.

- (NSString* const) kGCKMetadataKeyBroadcastDate

String key: Broadcast date.

The value is the date and/or time at which the media was first broadcast, in ISO-8601 format. For example, this could be the date that a TV show episode was first aired.

- (NSString* const) kGCKMetadataKeyTitle

String key: Title.

The title of the media. For example, this could be the title of a song, movie, or TV show episode. This value is suitable for display purposes.

- (NSString* const) kGCKMetadataKeySubtitle

String key: Subtitle.

The subtitle of the media. This value is suitable for display purposes.

- (NSString* const) kGCKMetadataKeyArtist

String key: Artist.

The name of the artist who created the media. For example, this could be the name of a musician, performer, or photographer. This value is suitable for display purposes.

- (NSString* const) kGCKMetadataKeyAlbumArtist

String key: Album artist.

The name of the artist who produced an album. For example, in compilation albums such as DJ mixes, the album artist is not necessarily the same as the artist(s) of the individual songs on the album. This value is suitable for display purposes.

- (NSString* const) kGCKMetadataKeyAlbumTitle

String key: Album title.

The title of the album that a music track belongs to. This value is suitable for display purposes.

- (NSString* const) kGCKMetadataKeyComposer

String key: Composer.

The name of the composer of a music track. This value is suitable for display purposes.

- (NSString* const) kGCKMetadataKeyDiscNumber

Integer key: Disc number.

The disc number (counting from 1) that a music track belongs to in a multi-disc album.

- (NSString* const) kGCKMetadataKeyTrackNumber

Integer key: Track number.

The track number of a music track on an album disc. Typically track numbers are counted starting from 1, however this value may be 0 if it is a "hidden track" at the beginning of an album.

- (NSString* const) kGCKMetadataKeySeasonNumber

Integer key: Season number.

The season number that a TV show episode belongs to. Typically season numbers are counted starting from 1, however this value may be 0 if it is a "pilot" episode that predates the official start of a TV series.

- (NSString* const) kGCKMetadataKeyEpisodeNumber

Integer key: Episode number.

The number of an episode in a given season of a TV show. Typically episode numbers are counted starting from 1, however this value may be 0 if it is a "pilot" episode that is not considered to be an official episode of the first season.

- (NSString* const) kGCKMetadataKeySeriesTitle

String key: Series title.

The name of a series. For example, this could be the name of a TV show or series of related music albums. This value is suitable for display purposes.

- (NSString* const) kGCKMetadataKeyStudio

String key: Studio.

The name of a recording studio that produced a piece of media. For example, this could be the name of a movie studio or music label. This value is suitable for display purposes.

- (NSString* const) kGCKMetadataKeyWidth

Integer key: Width.

The width of a piece of media, in pixels. This would typically be used for providing the dimensions of a photograph.

- (NSString* const) kGCKMetadataKeyHeight

Integer key: Height.

The height of a piece of media, in pixels. This would typically be used for providing the dimensions of a photograph.

- (NSString* const) kGCKMetadataKeyLocationName

String key: Location name.

The name of a location where a piece of media was created. For example, this could be the location of a photograph or the principal filming location of a movie. This value is suitable for display purposes.

- (NSString* const) kGCKMetadataKeyLocationLatitude

Double key: Location latitude.

The latitude component of the geographical location where a piece of media was created. For example, this could be the location of a photograph or the principal filming location of a movie.

- (NSString* const) kGCKMetadataKeyLocationLongitude

Double key: Location longitude.

The longitude component of the geographical location where a piece of media was created. For example, this could be the location of a photograph or the principal filming location of a movie.

- (NSString* const) kGCKMetadataKeyBookTitle

String key: Book title.

The title of an audio book.

Since: 4.3.5

- (NSString* const) kGCKMetadataKeyChapterNumber

Integer key: Chapter number.

The number of a chapter in an audio book.

Since: 4.3.5

- (NSString* const) kGCKMetadataKeyChapterTitle

String key: Chapter title.

The title of a chapter in a audio book.

Since: 4.3.5

- (NSString* const) kGCKMetadataKeySectionDuration

Double key: Section Duration.

The section duration in seconds. Used for queue metadata. For example, this could be a duration of one TV show in a queue, or a chapter duration of an audio book, or a program of a long live stream.

Since: 4.4.1

- (NSString* const) kGCKMetadataKeySectionStartTimeInMedia

Double key: Section Start Time in Media.

The offset of section start time from the start of the media item in seconds. Used for queue metadata.

Since: 4.4.1

- (NSString* const) kGCKMetadataKeySectionStartAbsoluteTime

Double key: Section Absolute Start Time.

The absolute time of section start, in epoch time in seconds. Used for queue metadata.

Since: 4.4.1

- (NSString* const) kGCKMetadataKeySectionStartTimeInContainer

Double key: Section Start Time in Container.

The offset of section start time within the full container. Used for queue metadata.

Since: 4.4.1

- (NSString* const) kGCKMetadataKeyQueueItemID

Double key: Queue Item ID.

The id of the queue item that includes the section start time. Used for queue metadata.

Since: 4.4.1

Property Detail

- (GCKMediaMetadataType) metadataType

readnonatomicassign

The metadata type.

GCKMediaMetadata Class

Overview

Instance Method Summary

Public Attributes

Property Summary

Method Detail

Member Data Documentation

Property Detail