Migration of a Chosen Architectural Pattern to Service Oriented ...

Chapter 5. Guidelines 117ViewViewControllerSchemaControllerPolicySchemaPolicyBasic Services+ Canonical Resources =Basic ServicesUtilityUtilityResourcesFigure 5.6: Migration step 6ViewViewControllerSchemaControllerPolicySchemaPolicyBasic ServicesBasic Services+ Entity Abstraction =UtilityUtilityResourcesResourcesEntityFigure 5.7: Migration step 78. Identify and wrap into services business rulesApplied SOA pattern: Rules CentralisationHow to: Business Rule can be both very simple like value ¿ 0 or a complextask that relays on many factors. It may be difficult to identify businessrules in code, because complex rules may be confused with process controlflow. Consequently other source (not only code and code comments) ofrules should be chosen. An alternative source of rules and constrains isa documentation (if exists). Firstly, business rules should be divided intothree groups:(a) First group contains rules that validate arguments of operations forinstance value >0.(b) The second group consist of business rules defining processes, for instance:“ (normal flow) . . . if value >0 then add else send message. . . (normal flow)”. Another example:“after adding an entity a newdocumentation has to be generated”(c) The third group contains rule describing requirements on level of objectsand relations between them, for instance“A supervisor may su-