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:
Inherits NSObject, <NSCopying>, and <NSSecureCoding>.
Method Detail
| - (instancetype) initWithMetadataType: | ( GCKMediaMetadataType ) | metadataType |
Initializes a new, empty, MediaMetadata with the given media type.
Designated initializer.
- Parameters
- metadataTypeThe 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
- imageThe image to add.
| - (BOOL) containsKey: | (NSString *) | key |
Tests if the object contains a field with the given key.
- Parameters
- keyThe key.
- Returns
-
YESif the field exists,NOotherwise.
| - (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
- keyThe key for the field.
- Returns
- The value of the field, or
nilif 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
- NSInvalidArgumentExceptionif 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
- keyThe key for the field.
- Returns
- The value of the field, or
nilif the field has not been set.
- Exceptions
- NSInvalidArgumentExceptionif 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
- NSInvalidArgumentExceptionif 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
- keyThe key for the field.
- Returns
- The value of the field, or 0 if the field has not been set.
- Exceptions
- NSInvalidArgumentExceptionif 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
- NSInvalidArgumentExceptionif 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
- NSInvalidArgumentExceptionif 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
- keyThe key for the field.
- Returns
- The value of the field, or 0 if the field has not been set.
- Exceptions
- NSInvalidArgumentExceptionif 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
- NSInvalidArgumentExceptionif 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
- NSInvalidArgumentExceptionif 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
- keyThe field name.
- Returns
- The date, or
nilif this field has not been set.
- Exceptions
- NSInvalidArgumentExceptionif 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
- keyThe field name.
- Returns
- The date as a string containing the restricted ISO-8601 representation of the date, or
nilif this field has not been set.
- Exceptions
- NSInvalidArgumentExceptionif the key refers to a predefined field which is not a date field.
Member Data Documentation
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.
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.
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.
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.
String key: Subtitle.
The subtitle of the media. This value is suitable for display purposes.
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.
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.
String key: Album title.
The title of the album that a music track belongs to. This value is suitable for display purposes.
String key: Composer.
The name of the composer of a music track. This value is suitable for display purposes.
Integer key: Disc number.
The disc number (counting from 1) that a music track belongs to in a multi-disc album.
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.
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.
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.
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.
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.
Integer key: Width.
The width of a piece of media, in pixels. This would typically be used for providing the dimensions of a photograph.
Integer key: Height.
The height of a piece of media, in pixels. This would typically be used for providing the dimensions of a photograph.
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.
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.
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.
String key: Book title.
The title of an audio book.
- Since
- 4.3.5
Integer key: Chapter number.
The number of a chapter in an audio book.
- Since
- 4.3.5
String key: Chapter title.
The title of a chapter in a audio book.
- Since
- 4.3.5
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
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
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
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
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
The metadata type.
