calculate (String, Object [], INodeHelper) [Documentation]

Index, Programmers Reference, Methods, IFunctionLibrary Interface, Calculate

public Object calculate (String functionName, Object [] parameters, INodeHelper helper)

This method is what the function is all about – it performs the required calculation and returns the result.

Parameters

`functionName`	the name of the function in the library that needs to be calculated
`parameters`	the values of function parameters as specified in a rule where the function is used. The given array contains Java objects corresponding to different attribute types (`String`, `Integer`, `DateHolder` etc – see a complete list in the Appendix A)
`helper`	a call-back interface. Should not be used by custom function libraries.

Returns

The result of the calculation as a Java object of the type corresponding to the attribute types – see Appendix A. If the function value cannot be calculated for whatever reason (for example, the number of parameters or their types are wrong), null should be returned.