Dynamic resolution of Fields returned from an RFC

[qswizzlejr]

I am working to convert old .net framework code using sapnco to .net core with yanco.

We have a set architecture where the our RFC handler is dynamically calling different RFC's by resolved name, ex

Z_READ_EMPLOYEES
Z_READ_CUSTOMERS
Z_READ_ORDERS

are all called via one generic API endpoint, in which invoke

public static EitherAsync<RfcErrorInfo, TResult> CallFunction<TRInput, TResult>(
            this IRfcContext context, 
            string functionName, 
            Func<Either<RfcErrorInfo, IFunction>, Either<RfcErrorInfo, TRInput>> Input, 
            Func<Either<RfcErrorInfo, IFunction>, Either<RfcErrorInfo, TResult>> Output,
            CancellationToken cancellationToken = default)

with functionName dynamically resolved to the models above using $"Z_READ_{model} (where model would be "EMPLOYEES", "CUSTOMERS" or "ORDERS")

Is there a way to dynamically resolve the available fields in the output lambda to map multiple varying models?

I have seen the way to get multiple fields using the from ... select syntax but haven't seen a way to dynamically get all the field names that are apart of the returned dataset, as the single call to RfcContext.CallFunction(...) might need to return a different model for each call depending on the values returned from SAP.

For instance, the zfunctions on SAP return their data in fields, some common, but all dependent on the type of data (employees, customers, orders) and the fields do not exist as tables or structures.

Is it even possible to have a generic output function in this way? Thanks!

[qswizzlejr]

Forgot to mention:

I saw the similar post #114 but that was answered using this solution using f.MapStructure(...) but the fields that are returned in my case aren't in a structure or a table, they are directly returned as values.

[fw2568]

To give you a better answer, could you please post the signature of the ABAP functions?

Z_READ_EMPLOYEES
Z_READ_CUSTOMERS
Z_READ_ORDERS

A part of it would be enough to understand your use case.

[qswizzlejr]

When I created the question, I didn't have permission to share the signatures, but I do now :)

For better context, we have a selection of forms that are pulling respective data from sap via read functions, in the same way as the original question. Several examples of the form signatures are below:

z_read_persInfo

*"*"Local Interface:
*"  IMPORTING
*"     VALUE(I_ROWGD) TYPE  /SAPPSPRO/_GUID_CHAR
*"  EXPORTING
*"     VALUE(E_UGUID) TYPE  ZUSRGUID
*"     VALUE(E_NACHN) TYPE  PAD_NACHN
*"     VALUE(E_VORNA) TYPE  PAD_VORNA
*"     VALUE(E_MIDNM) TYPE  PAD_MIDNM
*"     VALUE(E_RUFNM) TYPE  RUFNM
*"     VALUE(E_GBDAT) TYPE  GBDAT
*"     VALUE(E_PERID) TYPE  PRDNI
*"     VALUE(E_STRAS) TYPE  PAD_STRAS
*"     VALUE(E_LOCAT) TYPE  PAD_LOCAT
*"     VALUE(E_ORT01) TYPE  PAD_ORT01
*"     VALUE(E_STATE) TYPE  REGIO
*"     VALUE(E_PSTLZ) TYPE  PSTLZ_HR
*"     VALUE(E_COUNTY) TYPE  COUNC
*"     VALUE(E_TELNR) TYPE  TELNR
*"     VALUE(E_ALTNR) TYPE  TELNR
*"     VALUE(E_EMAIL) TYPE  COMM_ID_LONG
*"     VALUE(E_EC_FNM) TYPE  PAD_VORNA
*"     VALUE(E_EC_LNM) TYPE  PAD_NACHN
*"     VALUE(E_EC_PPH) TYPE  TELNR
*"     VALUE(E_EC_APH) TYPE  TELNR
*"     VALUE(E_EC_REL) TYPE  ZOBDT_ECREL
*"     VALUE(E_RACE) TYPE  RACKY
*"     VALUE(E_GESCH) TYPE  GESCH
*"     VALUE(E_VETST) TYPE  ZOBDT_VETST
*"     VALUE(E_COMPLETE) TYPE  BOOLE_D
*"     VALUE(E_CLOSED) TYPE  BOOLE_D
*"----------------------------------------------------------------------

z_read_0210

*"----------------------------------------------------------------------
*"*"Local Interface:
*"  IMPORTING
*"     VALUE(I_ROWGD) TYPE  /SAPPSPRO/_GUID_CHAR
*"     VALUE(I_TYPE) TYPE  SUBTY
*"  EXPORTING
*"     VALUE(E_UGUID) TYPE  ZUSRGUID
*"     VALUE(E_LNMCH) TYPE  LNMCH
*"     VALUE(E_TXSTA) TYPE  TXSTA_D
*"     VALUE(E_EXAMT) TYPE  EXAMT
*"     VALUE(E_MULT_JOBS_IND) TYPE  HRPAYUS_TAX_MULT_JOB_INDICATOR
*"     VALUE(E_DEPS_TOTAL_AMT) TYPE  HRPAYUS_DEPS_TOTAL_AMOUNT
*"     VALUE(E_OTHER_INC_AMT) TYPE  HRPAYUS_TAX_OTHER_INCOME_AMT
*"     VALUE(E_DEDUCT_AMT) TYPE  HRPAYUS_TAX_DEDUCT_AMT
*"     VALUE(E_COMPLETE) TYPE  BOOLE_D
*"     VALUE(E_CLOSED) TYPE  BOOLE_D
*"----------------------------------------------------------------------

z_read_acks

*"----------------------------------------------------------------------
*"*"Local Interface:
*"  IMPORTING
*"     VALUE(I_ROWGD) TYPE  /SAPPSPRO/_GUID_CHAR
*"  EXPORTING
*"     VALUE(E_RESULTS) TYPE  DB2_T_STRING
*"----------------------------------------------------------------------

We have several other functions, these are just a few examples for variety.

Thanks!

[fw2568]

Hello,

Since you know the signatures in all cases, I would suggest to create different mapping methods for all cases, e.g.

(pseudo code):

CallFunction($"Z_READ_{model}", 
  f => f.SetField("I_ROWGD", <Row>), 
  f =>MapModelOutput(f, model)

MapModelOutput(IFunction function, string model)
{
    switch(model){
       "EMPLOYEE" => MapEmployeeOutput(function)
    }
}

MapEmployeeOutput(IFunction function)
{
    return f.GetField<string>("E_NACHN") 
              select <Return Type>
}

f you prefer a fully dynamic method, you could also create some kind of dynamic evaluation of the fields. You already referred to the ToDictionary comment from here #114 (comment)

The IRfcRuntime also contains methods to evaluate all fields in the function signature:

https://github.com/dbosoft/YaNco/blob/a27637e44c6e92ed8bd9cd62cbab7bc69e9fa59d/src/YaNco.Abstractions/IRfcRuntime.cs#L41C48-L45

So, very similar to the GetFieldInfos method from the ToDictionary solution, you could also iterate over all the parameters in a function to dynamically map them to the output.
However, unless you are trying to write something very generic like a SAP PI/PO RFC adapter, you should normally try to create a representation of the abap signature in C# code - and stick with the first suggested solution.

Please also note our commercial support offering in case you need a more detailed analysis of your use case and some detailed code samples.

[qswizzlejr]

Thank you, I will look into it.

[qswizzlejr]

The RFCRuntime solution was the one I was looking for, thank you.

[fw2568]

You are welcome, thank you for the feedback.