A Service Component Model and Implementation for Institutional Repositories - Advanced Design Approaches to Emerging Software Systems - page 67

Figure 2. DRSC object

3.1.3. Content Component

approver. It may include Dublin Core metadata
that can be used to support simple queries. The
pointers refer to the locations of metadata com-
ponents, content components, log components
and annotation components. In addition, the re-
lationship between the ID component and other
component is 1:N. Also, the services provided
include registration, search and locating.

This is a component with the properties of mul-
tiple versions of resource content. The properties
of separate version include creation date, format,
and creator/modifier. The services include the
upload and the download services of the resource
content. For the upload process, if it is a new re-
source, a component is created; but for an existing
resource, the version and other information such
as the modification have to be stored separately
to keep the whole history of the digital resource.
This component supports the whole lifecycle of
the content of a DRSC object.

3.1.2. Metadata Component

This component not only includes the information
of the DRSC object itself, but also the relation-
ships with other DRSC objects. Its private prop-
erties include the general Dublin Core metadata
and other specific metadata. The relationships
with other digital object are expressed as binary
tuples such as (ID2, parent) that means the current
DRSC object is the parent of the DRSC objet with
ID2. Metadata component may also include the
redundant information such as the location of the
DRSC content component. There are two service
groups: data manipulation and data access.

3.1.4. Log Component

This is a component with the properties of operator,
operation type, operation text and operation result.
There are two kinds of logs: one is the access log
that doesn't change the metadata and content of
the DRSC object and the other records the opera-
tions that modify the metadata or content of the
DRSC object. Access log is a record of the access