Package tv.amwa.maj.union

Provides interfaces to a union type representing values which may contain one of many different sub-types, as used to specify matching criteria for search operations.

See:
Description

Interface Summary

DefinitionCriteria	Specifies a criteria for matching a definition as determined by class, kind, name etc..
DefinitionCriteriaByClass	Specifies a criteria for matching a definition determined by reference to the unique identifier of a class definition.
DefinitionCriteriaByKind	Specifies a criteria for matching a definition determined by its kind, such as data definition, property definition etc..
DefinitionCriteriaByName	Criteria for matching a definition by its name.
DefinitionCriteriaNoSearch	Specifies a criteria for matching a definition that matches nothing.
IdentificationCriteria	Specifies a criteria for matching an identification.
IdentificationCriteriaByIdGeneration	Specifies a criteria for matching an identification by its generation id.
IdentificationCriteriaByIdProductID	Specifies a criteria for matching an identification by its product id.
IdentificationCriteriaByIdRefImplVersion	Specifies a criteria for matching an identification by its reference implementation version, also known as its toolkit version.
IdentificationCriteriaNoIdSearch	Specifies a criteria for matching an identification that matches nothing.
SearchByAUID	Specifies a search criteria for matching mobs defined by an AUID value.
SearchByMediaCriteria	Specifies a search criteria for matching mobs defined by media criteria.
SearchByMobID	Specifies a search criteria for matching mobs defined by a mob id.
SearchByMobKind	Specifies a search criteria for matching mobs defined by a kind of mob.
SearchByName	Specifies a search criteria for matching mobs defined by mob name.
SearchCriteria	Specifies a search criteria for matching mobs specified in a number of different ways.
SearchForNothing	Specifies a search criteria for matching mobs that does not match anything.

Enum Summary

DefinitionCriteriaType	Defines the type of the associated criteria for matching a definition.
IdentificationCriteriaType	Defines the type of the associated criteria for matching an identification.
SearchTag	Specifies the type of criteria used to match mobs in a search criteria.

Package tv.amwa.maj.union Description

Provides interfaces to a union type representing values which may contain one of many different sub-types, as used to specify matching criteria for search operations. These interfaces are implemented in the MAJ API, amongst other method arguments, in the argument package.

The value of searches specified using the criteria of this package when the MAJ API is used in conjunction with a persistence entity manager is not clear. In this case, it is far better to define queries using an expressive query language that make use of the optimised search algorithms of the underlying store (database). However, searching using criteria is implemented in for searching for mobs and essence data in the MAJ API in a way that can be used by a standalone application. These methods use the search criteria defined in this package.

The identification criteria and definition criteria defined in this package are not currently used in the MAJ API and may be deprecated in the near future.

Heritage

The original versions of the interfaces of this package were derived from the union type definitions in the existing C-based AAF reference implementation, from file "AAFTypes.h". Java does not have a union type definition so abstract interfaces are used instead, with each sub-interface representing an element of the union. This is a little bit cumbersome as it requires several files Java for a concept that can be expressed so simply in C. However, it achieves the same result as each search criteria only takes the memory required to represent that criteria.

An example of the union type definition a set of criteria were derived from is:

    typedef struct _aafDefinitionCrit_t
    {
        aafDefinitionCritType_t type;
        union
        {
            aafDefinitionKind_t    defKind;
            aafString_t            name;
            aafClassID_t           objClass;
        } tags;
    } aafDefinitionCrit_t;

This converts into the Java abstract interface DefinitionCriteria with sub-interfaces DefinitionCriteriaByKind, DefinitionCriteriaByName and DefinitionCriteriaByClass. The type of the definition criteria is specified by enumeration DefinitionCriteriaType.

Author:

Richard Cartwright

See Also:

ContentStorage.getMobs(SearchCriteria), Header.getMobs(SearchCriteria)