MusicBrainz::Relation Class Reference

Represents a relation between two Entities. More...

List of all members.

Public Types
enum	Direction { DIR_BOTH, DIR_FORWARD, DIR_BACKWARD }
typedef std::vector< std::string >	Attributes
	A vector of strings (attributes).
Public Member Functions
	Relation (const std::string &relationType=std::string(), const std::string &targetType=std::string(), const std::string &targetId=std::string(), const Direction direction=DIR_BOTH, const Attributes &attributes=Attributes(), const std::string &beginDate=std::string(), const std::string &endDate=std::string(), Entity *target=NULL)
	Constructor.
virtual	~Relation ()
	Destructor.
std::string	getType () const
	Returns this relation's type.
void	setType (const std::string &type)
	Sets this relation's type.
std::string	getTargetId () const
	Returns the target's ID.
void	setTargetId (const std::string &targetId)
	Sets the target's ID.
std::string	getTargetType () const
	Returns the target's type.
void	setTargetType (const std::string &targetType)
	Sets the target's type.
std::string	getBeginDate () const
	Returns the begin date.
void	setBeginDate (const std::string &dateStr)
	Sets the begin date.
std::string	getEndDate () const
	Returns the end date.
void	setEndDate (const std::string &dateStr)
	Sets the end date.
Direction	getDirection () const
	Returns the reading direction.
void	setDirection (const Direction direction)
	Sets the reading direction.
Attributes &	getAttributes ()
	Returns a list of attributes describing this relation.
int	getNumAttributes () const
	Returns number of attributes.
std::string	getAttribute (int index) const
	Returns an attribute specified by index.
void	addAttribute (const std::string &attribute)
	Adds an attribute to the list.
Entity *	getTarget () const
	Returns this relation's target object.
void	setTarget (Entity *target)
	Sets this relation's target object.
Static Public Attributes
static const std::string	TO_ARTIST
	Identifies relations linking to an artist.
static const std::string	TO_RELEASE
	Identifies relations linking to a release.
static const std::string	TO_TRACK
	Identifies relations linking to a track.
static const std::string	TO_URL
	Identifies relations linking to an URL.

---

Detailed Description

Represents a relation between two Entities.

There may be an arbitrary number of relations between all first class objects in MusicBrainz. The Relation itself has multiple attributes, which may or may not be used for a given relation type.

Note that a Relation object only contains the target but not the source end of the relation.

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Member Typedef Documentation

typedef std::vector<std::string> MusicBrainz::Relation::Attributes

A vector of strings (attributes).

---

Member Enumeration Documentation

enum MusicBrainz::Relation::Direction

Enumerator:

DIR_BOTH	Relation reading direction doesn't matter.
DIR_FORWARD	Relation reading direction is from source to target.
DIR_BACKWARD	Relation reading direction is from target to source.

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Constructor & Destructor Documentation

MusicBrainz::Relation::Relation	(	const std::string &	relationType = std::string(),
		const std::string &	targetType = std::string(),
		const std::string &	targetId = std::string(),
		const Direction	direction = DIR_BOTH,
		const Attributes &	attributes = Attributes(),
		const std::string &	beginDate = std::string(),
		const std::string &	endDate = std::string(),
		Entity *	target = NULL
	)

Constructor.

Parameters:

	relationType	a string containing an absolute URI
	targetType	a string containing an absolute URI
	targetId	a string containing an absolute URI
	direction	one of Relation::DIR_FORWARD, Relation::DIR_BACKWARD, or Relation::DIR_BOTH
	attributes	a list of strings containing absolute URIs
	beginDate	a string containing a date
	endDate	a string containing a date
	target	an instance of a subclass of Entity, or NULL

virtual MusicBrainz::Relation::~Relation

(

)

[virtual]

Destructor.

---

Member Function Documentation

void MusicBrainz::Relation::addAttribute

(

const std::string &

attribute

)

Adds an attribute to the list.

Parameters:

attribute

a string containing an absolute URI

std::string MusicBrainz::Relation::getAttribute

(

int

index

)

const

Returns an attribute specified by index.

This is equivalent to getAttributes()[index]

Returns:

a string containing the attribute

See also:

getAttributes

Attributes& MusicBrainz::Relation::getAttributes

(

)

Returns a list of attributes describing this relation.

The attributes permitted depend on the relation type.

Returns:

a list of strings containing absolute URIs

std::string MusicBrainz::Relation::getBeginDate

(

)

const

Returns the begin date.

The definition depends on the relation's type. It may for example be the day of a marriage or the year an artist joined a band. For other relation types this may be undefined.

Returns:

a string containing a date

Direction MusicBrainz::Relation::getDirection

(

)

const

Returns the reading direction.

The direction may be one of Relation::DIR_FORWARD, Relation::DIR_BACKWARD, or Relation::DIR_BOTH, depending on how the relation should be read. For example, if direction is Relation::DIR_FORWARD for a cover relation, it is read as "X is a cover of Y". Some relations are bidirectional, like marriages. In these cases, the direction is Relation::DIR_BOTH.

Returns:

Relation::DIR_FORWARD, Relation::DIR_BACKWARD, or Relation::DIR_BOTH

std::string MusicBrainz::Relation::getEndDate

(

)

const

Returns the end date.

As with the begin date, the definition depends on the relation's type. Depending on the relation type, this may or may not be defined.

Returns:

a string containing a date

See also:

getBeginDate

int MusicBrainz::Relation::getNumAttributes

(

)

const

Returns number of attributes.

This is equivalent to getAttributes().size()

Returns:

an int containing number of attributes

See also:

getAttributes

Entity* MusicBrainz::Relation::getTarget

(

)

const

Returns this relation's target object.

Note that URL relations never have a target object. Use the getTargetId method to get the URL.

Returns:

a subclass of Entity, or NULL

std::string MusicBrainz::Relation::getTargetId

(

)

const

Returns the target's ID.

This is the ID the relation points to. It is an absolute URI, and in case of an URL relation, it is a URL.

Returns:

a string containing an absolute URI

std::string MusicBrainz::Relation::getTargetType

(

)

const

Returns the target's type.

For MusicBrainz data, the following target types are defined:

• artists: Relation::TO_ARTIST
• releases: Relation::TO_RELEASE
• tracks: Relation::TO_TRACK
• urls: Relation::TO_URL

Returns:

a string containing an absolute URI

std::string MusicBrainz::Relation::getType

(

)

const

Returns this relation's type.

Returns:

a string containing an absolute URI

void MusicBrainz::Relation::setBeginDate

(

const std::string &

dateStr

)

Sets the begin date.

Parameters:

dateStr

a string containing a date

See also:

getBeginDate

void MusicBrainz::Relation::setDirection

(

const Direction

direction

)

Sets the reading direction.

Parameters:

direction

Relation::DIR_FORWARD, Relation::DIR_BACKWARD, or Relation::DIR_BOTH

See also:

getDirection

void MusicBrainz::Relation::setEndDate

(

const std::string &

dateStr

)

Sets the end date.

Parameters:

dateStr,:

a string containing a date

See also:

getBeginDate

void MusicBrainz::Relation::setTarget

(

Entity *

target

)

Sets this relation's target object.

Note that URL relations never have a target object, they are set using setTargetId.

Parameters:

target

a subclass of Entity, or NULL

void MusicBrainz::Relation::setTargetId

(

const std::string &

targetId

)

Sets the target's ID.

Parameters:

targetId

a string containing an absolute URI

See also:

getTargetId

void MusicBrainz::Relation::setTargetType

(

const std::string &

targetType

)

Sets the target's type.

Parameters:

targetType

a string containing an absolute URI

See also:

getTargetType

void MusicBrainz::Relation::setType

(

const std::string &

type

)

Sets this relation's type.

Parameters:

type

a string containing an absolute URI

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Member Data Documentation

const std::string MusicBrainz::Relation::TO_ARTIST [static]

Identifies relations linking to an artist.

const std::string MusicBrainz::Relation::TO_RELEASE [static]

Identifies relations linking to a release.

const std::string MusicBrainz::Relation::TO_TRACK [static]

Identifies relations linking to a track.

const std::string MusicBrainz::Relation::TO_URL [static]

Identifies relations linking to an URL.