Understanding Delivery
Understanding Delivery
The Rosetta system enables users to view objects such as intellectual entities, representations, and files that are stored in the Rosetta system. These objects can be viewed by staff users (for example, Assessors viewing content deposited by Producer Agents) as well as external users (for example, a reader with a subscription to the library), also referred to as content consumers.
The diagram below illustrates the organization of the components that enable content delivery.
Delivery Information Flow
The delivery flow consists of the following stages:
- A content consumer uses an external application to request a content object from the Rosetta system.
- The external application sends the request to the Delivery Manager.
- The Delivery Manager retrieves the content from the repository.
- The Access Rights Checker determines whether the content consumer has the appropriate privileges to view the requested content object.
- If the content consumer possesses the necessary viewing access rights, the system determines whether there are concurrent user access rights set for the IE. If so, the Access Rights Checker determines the number of copies currently in use by other users. If the number is less than the maximum allowed at one time, the user is registered as a viewer of the IE, the IE is delivered to the user, and one of the available open copies becomes unavailable. If all available copies are in use, the user is asked to wait and try again.
- The Delivery Rules Manager verifies the input parameters of the content object (for example, whether the object is an IE, a representation, or a file), and determines which representation profile should be used to display the content object.
- The selected representation is prepared to be viewed by the viewer. The viewer might require the representation or file to be processed by a component called a pre-processor, which is a plug-in that migrates the files or the metadata of the object.
- When the viewer preprocessor finishes processing the content object, the object is redirected to the viewer, either an internal viewer bundled with Rosetta or an external viewer that resides outside of Rosetta.
- The resource discovery channel (for example, Primo) or OPAC displays the content to the content consumer.
- If concurrent user access rights are being applied: While the user has the IE checked out, the viewer and server exchange information about the user’s activity related to the IE. If no activity occurs within a set amount of time (by default, two minutes), the user is disconnected and the IE becomes available to another user.