OTJ Primer

Is this the right level for me?

• If you're quite rushed maybe the Object Teams Quick-Start is better suited.
• If, on the other hand, you look for literature on the background of the concepts of Object Teams, the list of scientific publications has all you need. From these, the following is the most comprehensive recent coverage of Object Teams: A Precise Model for Contextual Roles: The Programming Language ObjectTeams/Java -- (Journal Applied Ontology 2007)

This page with its sub-pages tries to cover the middle ground, addressing readers who do want to learn the essential concepts of Object Teams without the burden of a detailed scientific discussion.

Throughout this text references into the OT/J Language Definition are given like this (see OTJLD §0), where the interested reader will find the detailed definitions.

The programming language OT/J introduces two new kinds of classes

• Teams
• Roles

However, it is much more interesting to look at what happens between these things.
Here, OT/J introduces the following major relations:

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Role Playing

Role classes/objects are playedBy base classes/objects. The communication between the two part objects is defined using

• callout method bindings for forwarding role-to-base
• callin method bindings for intercepting method calls base-to-role

→ Details on Role Playing ...

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Role Containment

Role classes/objects are contained in a team instance.

• Roles preferably communicate with other roles.
• Roles can be confined to their enclosing team to protect them against external access
• Data-flows between a team and its outside apply translation polymorphism to translate between roles and bases:
  • sending a role object to the outside applies lowering (role-to-base translation)
  • sending a base object into a team applies lifting (base-to-role translation)
• Team activation controls the enablement of callin bindings

→ Details on Role Containment ...

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Team Inheritances

• A team class can be sub-classed including all its contained roles (similar to Java classes with inner classes)
• A sub-team can override any of its inherited roles (different from Java inner classes).
• An overriding role implicitly inherits from its overridden version.

→ Details on Team Inheritances ...