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Extended Functions

Regulator|Scripting API · C# 14

For developing extensive and complex regulations, the engine's runtime functions can be extended with custom C# classes. This is an advanced pattern typically used by Regulation Developers or Automators — it requires a .NET development environment. Standard No-Code and Low-Code regulation work does not require this.

Externalizing functions offers several advantages:

  • Code can be reused by higher-level regulations
  • Development in professional IDEs (syntax highlighting, IntelliSense, etc.)
  • Debug support for case and report scripts
  • Better integration with version control systems

The implementation involves three steps: 1. Implement the business functions in C# 2. Register the function extension 3. Use the extended functionality

Composite Function

The business functions are C# classes that receive the WageTypeValueFunction as a constructor argument:

using System;
using PayrollEngine.Client.Scripting.Function;
namespace ExtendedPayroll.Scripts;
public class CompositeWageTypeValueFunction
{
  private WageTypeValueFunction Function { get; }
  public CompositeWageTypeValueFunction(WageTypeValueFunction function)  // constructor
  {
    Function = function ?? throw new ArgumentNullException(nameof(function));
  }
  public decimal GetSalary()           // custom wage type value method
  {
    return Function.CaseValue["Salary"];
  }
}

Function Registration

In the next step, WageTypeValueFunction is extended using partial to expose access to the composite type:

using ExtendedPayroll.Scripts;
namespace PayrollEngine.Client.Scripting.Function;
public partial class WageTypeValueFunction          // extend with partial
{
  private CompositeWageTypeValueFunction function;
  public CompositeWageTypeValueFunction MyRegulation => function ??= new(this);  // expose composite
}

Extended Function Usage

The extension class can be used in the wage type ValueExpression: 

"wageTypes": [
  {
    "wageTypeNumber": 100,
    "name": "Salary",
    "valueExpression": "MyRegulation.GetSalary()"  // call extended function
  }
]

The extension can be verified with the Payroll Console: 

PayrollConsole PayrunEmployeeTest Test.et.json

Next Steps