The RAPK interface describes a prototype of a
Kahn-Wilensky style repository
service. RAPK is an acronym for Repository Access Protocol for
Knowbot Programs. The Intellectual Property Rights
Management demo implements an Image Repository service that
conforms to the RAPK inteface.
Notes
- CNRI is conducting ongoing research into repositories and the
Repository Access Protocol as part of its work on digitial library
systems. For more information see An
Architecture for Information in Digital Libraries by W. Arms,
et al. The RAPK interface defined below is a prototype used in
the KOE only; it may bear little resemblance to the current RAP
definition.
- A good grasp of the terminology defined in the papers
referenced above is necessary to understand the documentation of
this interface.
- This interface defines additional undocumented types. These
are used in CNRI demonstrations that are not distributed with the
KOE software.
This interface imports the Mapping interface.
This interface defines the following non-object types:
- String
- An alias for ilu.CString
- Strings
- An alias for SEQUENCE OF String
- Handle
- A type representing a CNRI
Handle, currently an alias for the String type.
- Handles
- An alias for SEQUENCE OF Handle
- CardinalOrNull
- An alias for OPTIONAL CARDINAL
- Iterator
- An alias for CARDINAL
- TermsAndConditions
- A type representing the terms and conditions of use of a
digital object. Currently an alias for
Mapping.StringMap
- Metadata
- A type representing a digital object's metadata. Currently an
alias for
Mapping.StringMap
This interface defines the following exceptions:
- TypeError
- A digital object cannot produce the requested
dissemination type.
- NotFound
- A handle refers to a non-existent digital object.
- LastDocument
- An iterator has reached the last document.
- BadIterator
- An invalid iterator was used.
- ReadError
- An error occurs while reading a dissemination's data.
- TermsAndConditionsFailure
- The rights to a digital object have not been satisfied.
This interface defines the following object types:
- Repository
- The object representing a repository.
- DigitalObject
- This object represents the somewhat abstract notion of a
"digital object". Digital objects have metadata
associated with them, and may also have terms and
conditions
of use which must be satisfied before they can be legally used.
A digital object may also have any number of
"disseminations" which are used to retrieve the typed
data of a digital object.
Note that the terms and conditions must be negotiated for
a dissemination before that dissemination can be retrieved.
Not all disseminations require terms and conditions
negotiation, but all disseminations have an interface for
negotiating terms and conditions.
Terms and conditions negotiation is currently
very simple.
To find out what terms you must satisfy, use the
GetTermsAndConditions() method, which returns a
Mapping object (disguised as a the
TermsAndConditions type). The keys of this object
are the terms which must be satisfied or conditions which can
be queried. The values are either values used by clients
negotiating the terms and conditions, or are expected to
be set by the clients in order to satisfy a condition. The
actual set of terms and conditions keys and the expected
values are implementation dependent.
- Dissemination
- The object representing the typed data of a digital object.
Clients use the Dissemination, for example, to read
the JPEG data of a thumbnail image represented in a digital
object.
- GetRepoMetadata () : Metadata
- Return the repository's metadata object.
- Scan () : Handles
- Return a list of all handles registered in the
repository.
- GetMetadata (hdl : Handle) : Metadata
- Return the metadata associated with the digital object
referenced by the handle hdl. Raise
NotFound if there is no digital object
for the given handle.
- GetDO (hdl : Handle) : DigitalObject
- Return the digital object reference by handle
hdl. Raise NotFound if there
is no digital object for the given handle.
- GetTermsAndConditions
(hdl : Handle) : TermsAndConditions
- Return the terms and conditions for the digital object
reference by handle hdl. Raise NotFound
if there is no digital object for the given
handle.
- CreateIterator () : Iterator
- Create an iterator over the handles for the digital
objects registered in the repository.
- Iterate (token : Iterator) : Handle
- Return the next handle in the set of handles iterated over
via the given token. Raise
LastDocument when the iterator has moved past the
last document in the list. Raise BadIterator
when the given token is not a valid iterator.
- GetMetadata () : Metadata
- Return the metadata for the digital object.
- GetTermsAndConditions () : TermsAndConditions
- Return the terms and conditions for the digital
object.
- GetDissemination
(dtype : String) : Dissemination
- Return a dissemination of the digital object, of the
type specified by dtype. The list of
dissemination types is typically defined in the
metadata of the digital object. This method raises
TypeError for if an invalid dissemination
type is specified. It raises
TermsAndConditions if the terms and
conditions for use of the dissemination have not been
satisfied.
- GetTermsAndConditions () : TermsAndConditions
- Return the terms and conditions for the digital
object.
- Read (Size : CardinalOrNull) : String
- Read Size bytes of the dissemination's data.
Raise ReadError if the read fails. Raise
TermsAndConditionsFailure if the terms and
conditions for use of the dissemination have not been
satisfied.
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