The Repository OSID provides the service of finding and
managing digital assets.
Asset represents a unit of content,
whether it be an image, a video, an application document
or some text. The Asset defines a core set of definitions
applicable to digital content, such as copyright and
publisher, and allows for a type specification to be
appended as with other
Asset content, such as a document, is defined such
that there may be multiple formats contained with the same
asset. A document may be accessible in both PDF and MS
Word, but is the same document, for example. An image may
have both a large size and a thumbnail version. Generally,
an asset contains more than one version of content when it
is left to the application to decide which is most
define methods in common throughout the content
variations. An example asset is one whose content
Types are "Quicktime" and "MPEG", but the
Type is "movie" and defines
methods that describe the move aside from the formats.
This "double" Type hierarchy stemming from the asset
requires more care in defining interfaces.
Assets also have "credits" which define
the authors, editors, creators, performers, producers or
any other "role", identified with a role
with the production of the asset. These are
managed externally to the asset through another
Through additional optional
Asset can be "extended" to
offer temporal information. An asset may pertain to a
date, a period of time, or a series of dates and periods.
This mechanism is to offer the ability to search for
assets pertaining to a desired date range without
requiring understanding of a
Asset can also map to
spatial information. A photograph may be "geotagged" with
the GPS coordinates where it was taken, a conical shape in
stellar coordinates could be described for an astronimocal
image, or there may be a desire to may a historical book
to the spatial coordinates of Boston and Philadelphia.
Unlike temporal mappings, the definition of the spatial
coordinate is left to a spatial Type to define. The
Repository OSID simply manages spatial mappings to the
Assets may also relate to Ontology OSID
provides the ability to normalize information related to
subject matter across the
simplify management and provide a more robust searching
mechanism. For example, with a photograph of the Empire
State Building, one may wish to describe that it was
designed by Shreve, Lamb and Harmon and completed in 1931.
The information about the building itself can be described
Subject and related to the
photograph, and any other photograph that captures the
the photograph may simply be "photograph" and doesn't
attempt to describe a building, while the
Type is "image/jpeg".
An application performing a search for Empire State
Building can be execute the search over the
Subjects, and once the user has narrowed the
subject area, then the related Assets can be retrieved,
and from there negotiate the content.
A provider wishing to construct a simple inventory
database of buildings in New York may decide to do so
using the Resource OSID. The
Type may describe the construction dates,
height, location, style and architects of buildings. The
Type may also include a means of getting a
reference image using the
Since there is no explicit relationship between
Resource can be adapted to the
interface (mapping a
buildingSubjectType ) to use
the same data for
mappings and searching.
Asset compositions can be created using the
Composition interface. A
is a group of
compositions may be structured into a hierarchy for the
purpose of "building" larger content. A content management
system may make use of this interface to construct a web
Composition hierarchy may map
into an XHTML structure and each
represent an image or a link in the document. However, the
produced web page at a given URL may be represented by
Asset that whose content has
both the URL and the XHTML stream.
Another example is an IMS Common Cartridge. The
Composition may be used to produce the zip file
cartridge, but consumers may access the zip file via an
may be categorized into
Repository is a catalog-like
interface to help organize assets and subject matter.
Repositories may be organized into hierarchies for
organization or federation purposes.
This number of service aspects to this Repository OSID
produce a large number of definitions. It is recommended
to use the
RepositoryManager definition to
select a single
OsidSession of interest,
and work that definition through its dependencies before
tackling another aspect.
The Repository OSID includes a rules subpackage for
managing dynamic compositions.