Attribute-oriented programming (@OP) is a program-level marking technique. Programmers can mark program elements (e.g. classes and methods) to indicate that they maintain application-specific or domain-specific semantics. For example, some programmers may define a "logging" attribute and associate it with a method to indicate the method should implement a logging function, while other programmers may define a "web service" attribute and associate it with a class to indicate the class should be implemented as a web service. Attributes separate application's core logic (or business logic) from application-specific or domain-specific semantics (e.g. logging and web service functions). By hiding the implementation details of those semantics from program code, attributes increase the level of programming abstraction and reduce programming complexity, resulting in simpler and more readable programs. The program elements associated with attributes are transformed to more detailed programs by a supporting tool (e.g. preprocessor). For example, a preprocessor may insert a logging program into the methods associated with a "logging" attribute.
Attribute-oriented programming in various languages
With the inclusion of The Metadata Facility for the Java Programming Language (JSR-175) into the J2SE 5.0 release it is possible to utilize attribute-oriented programming right out of the box. XDoclet library makes it possible to use attribute-oriented programming approach in earlier versions of Java.
The C# language has supported attributes from its very first release. However these attributes are used to give run-time information and are not used by a pre-processor (there isn't one in C#'s reference implementation).
The Hack programming language supports attributes. Attributes can be attached to various program entities, and information about those attributes can be retrieved at run-time via reflection.
- "Attribute-Oriented Programming". An Introduction to Attribute-Oriented Programming. Archived from the original on May 26, 2005. Retrieved July 22, 2005.
- Wada, Hiroshi; Suzuki, Junichi (2005). "Modeling Turnpike Frontend System: a Model-Driven Development Framework Leveraging UML Metamodeling and Attribute-Oriented Programming" (PDF). In Proc. of the 8th ACM/IEEE International Conference on Model Driven Engineering Languages and Systems (MoDELS/UML 2005).
- Rouvoy, Romain; Merle, Philippe (2006). "Leveraging Component-Oriented Programming with Attribute-Oriented Programming" (PDF). In Proc. of the 11th ECOOP International Workshop on Component-Oriented Programming (WCOP 2006). Archived from the original (PDF) on 2006-12-23.
- Don Schwarz. Peeking Inside the Box: Attribute-Oriented Programming with Java5.
- Sun JSR 175.
- Attributes and Reflection - sample chapter from Programming C# book.
- Modeling Turnpike Project.
- Fraclet: An annotation-based programming model for the Fractal component model.
- Attribute Enabled Software Development book