Summary
Interfaces, contracts, methods, operations, entities, objects, and tables, oh my! The OSID Specification defines its own language solely in reference to itself. The vocabulary is defined and built upon without importing words from outside the OSIDs.
...
The OSID Specification schema (XS-OSID) defines:
- osid: a bunch of interfaces an enumerations
- enumeration: a list of values
- interface: a bunch of method definitions
- method: something that is invoked with parameters, returns a value or an error
- parameter: defines what may be supplied to a method as an argument, can be an interface, enumeration, or a language primitive
- return: defines what may be returned from a method, if anything, can be an interface, enumeration, or a language primitive
- language primitive: boolean, byte, cardinal. decimal integer, object. string, timestamp
- error: an error from a method such as OPERATION_FAILED or ILLEGAL_STATE
- compliance: a compliance statement for a method - mandatory or optional
...
The term contract is often used in service designs to distinguish an interface from a message structure or DTO. The message structure and DTO are considered data while the contract defines the operations on that data. OSIDs define the agreement between service consumers and service providers. In the OSID world, most everything in the specification can be considered a contract, i.e. "The AgentList is a contract."
DTO (DAO, Bean, Domain Object)
A Data Transfer Object is used to transfer bags of data values. However, OSIDs are interfaces into OSID Providers. OSID Providers may be dynamic and DTOs are static.
...