The implementation of the pattern has been written in Java v. 18 using the IntelliJ IDEA.
The Open JDK 18.0.1 General-Availability Release has been used: Open JDK.
The Java source code of the pattern implementation has been placed in src/pl/gdynia/amw/scdp package.
Navigate to: SCDP source code
Whereas, tests for the implementation have been placed in tests/pl/gdynia/amw/scdp package.
Navigate to: SCDP tests
The following pattern layers have been identified: Abstract and Concrete. The Abstract layer consists of the SmartContract abstract class and the VerificationRule interface. Whereas, the Concrete layer uses classes implementation-specific for concrete smart contract. Diverse object-oriented paradigms and constructs have been employed in the definition of the pattern. Inheritance allows for providing the common abstract type for smart contracts. Moreover, the interface enforces the implementation of the same validation method.
The abstract class SmartContract declares the list of rules and uses the definition of the VerificationRule interface. The interface defines runRule() method that must be implemented by concrete verification rule class.
As an example, the specific ExchangeEnergyContract class actually implements checkSC() method that iterates over the list of actual verification rules. Five concrete verification rules have been implemented: two technical, two business, and one expanding.
The design of the pattern puts emphasis on the order of storing verification rules in an array-backed list. The list of rules is evaluated unless one of them is not met. Then the verification is aborted and the transaction is not executed. Such a design manner may lead to shortening the smart contract validation time. The pattern also fosters the reusability of verification rules.