Dynamic Function Result

README.md

@@ -110,6 +110,18 @@ var result = someFunction.Invoke<SomeFunctionResult>(new SomeFunctionParameters
 // Do something with result.Abc
 ```
 
+### Call function with dynamic input and output parameters
+
+```csharp
+using var someFunction = connection.CreateFunction("BAPI_SOME_FUNCTION_NAME");
+var result = someFunction.Invoke<dynamic>(new
+{
+    SOME_FIELD = "Some value",
+});
+
+string abc = result.RES_ABC;
+```
+
 ### Define models with a nested structure
 
 ```csharp

src/SapNwRfc/Internal/Dynamic/DynamicRfc.cs

@@ -0,0 +1,97 @@
+using System;
+using SapNwRfc.Internal.Fields;
+using SapNwRfc.Internal.Interop;
+
+namespace SapNwRfc.Internal.Dynamic
+{
+    internal static class DynamicRfc
+    {
+        internal static bool TryGetRfcValue(RfcInterop interop, IntPtr dataHandle, string name, SapRfcType type, Func<ISapTypeMetadata> typeMetadata, Type returnType, out object result)
+        {
+            result = GetRfcValue(interop, dataHandle, name, type, typeMetadata);
+
+            if (returnType == typeof(object))
+            {
+                return true;
+            }
+
+            try
+            {
+                result = Convert.ChangeType(result, returnType);
+                return true;
+            }
+            catch { }
+
+            result = null;
+            return false;
+        }
+
+        private static object GetRfcValue(RfcInterop interop, IntPtr dataHandle, string name, SapRfcType type, Func<ISapTypeMetadata> typeMetadata)
+        {
+            switch (type)
+            {
+            case SapRfcType.RFCTYPE_CHAR:
+            case SapRfcType.RFCTYPE_NUM:
+            case SapRfcType.RFCTYPE_BCD:
+            case SapRfcType.RFCTYPE_STRING:
+                return StringField.Extract(interop, dataHandle, name).Value;
+
+            case SapRfcType.RFCTYPE_INT:
+            case SapRfcType.RFCTYPE_INT1:
+            case SapRfcType.RFCTYPE_INT2:
+                return IntField.Extract(interop, dataHandle, name).Value;
+
+            case SapRfcType.RFCTYPE_INT8:
+                return LongField.Extract(interop, dataHandle, name).Value;
+
+            case SapRfcType.RFCTYPE_FLOAT:
+                return DoubleField.Extract(interop, dataHandle, name).Value;
+
+            case SapRfcType.RFCTYPE_DECF16:
+            case SapRfcType.RFCTYPE_DECF34:
+                return DecimalField.Extract(interop, dataHandle, name).Value;
+
+            case SapRfcType.RFCTYPE_DATE:
+                return DateField.Extract(interop, dataHandle, name).Value;
+
+            case SapRfcType.RFCTYPE_TIME:
+                return TimeField.Extract(interop, dataHandle, name).Value;
+
+            case SapRfcType.RFCTYPE_BYTE:
+            case SapRfcType.RFCTYPE_XSTRING:
+                return BytesField.Extract(interop, dataHandle, name, bufferLength: 0).Value;
+
+            case SapRfcType.RFCTYPE_TABLE:
+                {
+                    RfcResultCode resultCode = interop.GetTable(
+                        dataHandle: dataHandle,
+                        name: name,
+                        tableHandle: out IntPtr tableHandle,
+                        errorInfo: out RfcErrorInfo errorInfo);
+
+                    resultCode.ThrowOnError(errorInfo);
+
+                    return new DynamicRfcTable(interop, tableHandle, typeMetadata());
+                }
+
+            case SapRfcType.RFCTYPE_STRUCTURE:
+                {
+                    RfcResultCode resultCode = interop.GetStructure(
+                        dataHandle: dataHandle,
+                        name: name,
+                        structHandle: out IntPtr structHandle,
+                        errorInfo: out RfcErrorInfo errorInfo);
+
+                    resultCode.ThrowOnError(errorInfo);
+
+                    return new DynamicRfcStructure(interop, structHandle, typeMetadata());
+                }
+
+            case SapRfcType.RFCTYPE_NULL:
+                return null;
+            }
+
+            throw new NotSupportedException($"Parameter type {type} is not supported");
+        }
+    }
+}

src/SapNwRfc/Internal/Dynamic/DynamicRfcFunction.cs

@@ -0,0 +1,158 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Dynamic;
+using SapNwRfc.Internal.Interop;
+
+namespace SapNwRfc.Internal.Dynamic
+{
+    internal sealed class DynamicRfcFunction : DynamicObject, IReadOnlyDictionary<string, object>
+    {
+        private readonly RfcInterop _interop;
+        private readonly IntPtr _functionHandle;
+        private readonly ISapFunctionMetadata _functionMetadata;
+
+        internal DynamicRfcFunction(RfcInterop interop, IntPtr functionHandle, ISapFunctionMetadata functionMetadata)
+        {
+            _interop = interop;
+            _functionHandle = functionHandle;
+            _functionMetadata = functionMetadata;
+        }
+
+        private bool TryGetByName(string name, Type returnType, out object result)
+        {
+            if (_functionMetadata.Parameters.TryGetValue(name, out ISapParameterMetadata parameter))
+            {
+                if (DynamicRfc.TryGetRfcValue(_interop, _functionHandle, parameter.Name, parameter.Type, parameter.GetTypeMetadata, returnType, out result))
+                {
+                    return true;
+                }
+            }
+
+            result = null;
+            return false;
+        }
+
+        private bool TryGetByIndex(int index, Type returnType, out object result)
+        {
+            if (index >= 0 && index < _functionMetadata.Parameters.Count)
+            {
+                ISapParameterMetadata parameter = _functionMetadata.Parameters[index];
+
+                if (DynamicRfc.TryGetRfcValue(_interop, _functionHandle, parameter.Name, parameter.Type, parameter.GetTypeMetadata, returnType, out result))
+                {
+                    return true;
+                }
+            }
+
+            result = null;
+            return false;
+        }
+
+        public override IEnumerable<string> GetDynamicMemberNames()
+        {
+            return Keys;
+        }
+
+        public override bool TryGetMember(GetMemberBinder binder, out object result)
+        {
+            return TryGetByName(binder.Name, binder.ReturnType, out result);
+        }
+
+        public override bool TryGetIndex(GetIndexBinder binder, object[] indexes, out object result)
+        {
+            if (indexes.Length != 1)
+                throw new ArgumentOutOfRangeException(nameof(indexes));
+
+            var index = indexes[0];
+
+            if (index is string name)
+                return TryGetByName(name, binder.ReturnType, out result);
+
+            if (index is int i)
+                return TryGetByIndex(i, binder.ReturnType, out result);
+
+            if (index is uint u)
+                return TryGetByIndex((int)u, binder.ReturnType, out result);
+
+            throw new ArgumentException(nameof(indexes));
+        }
+
+        public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
+        {
+            if (binder.Name == "GetMetadata" && binder.CallInfo.ArgumentCount == 0)
+            {
+                result = _functionMetadata;
+                return true;
+            }
+
+            return base.TryInvokeMember(binder, args, out result);
+        }
+
+        public IEnumerable<string> Keys
+        {
+            get
+            {
+                foreach (var parameter in _functionMetadata.Parameters)
+                {
+                    yield return parameter.Name;
+                }
+            }
+        }
+
+        public IEnumerable<object> Values
+        {
+            get
+            {
+                foreach (var parameter in _functionMetadata.Parameters)
+                {
+                    if (TryGetByName(parameter.Name, typeof(object), out object result))
+                    {
+                        yield return result;
+                    }
+                }
+            }
+        }
+
+        public int Count => _functionMetadata.Parameters.Count;
+
+        public object this[string key]
+        {
+            get
+            {
+                if (TryGetByName(key, typeof(object), out var result))
+                {
+                    return result;
+                }
+
+                throw new KeyNotFoundException();
+            }
+        }
+
+        public bool ContainsKey(string key)
+        {
+            return _functionMetadata.Parameters.TryGetValue(key, out _);
+        }
+
+        public bool TryGetValue(string key, out object value)
+        {
+            return TryGetByName(key, typeof(object), out value);
+        }
+
+        public IEnumerator<KeyValuePair<string, object>> GetEnumerator()
+        {
+            foreach (var parameter in _functionMetadata.Parameters)
+            {
+                if (TryGetByName(parameter.Name, typeof(object), out object result))
+                {
+                    yield return new KeyValuePair<string, object>(parameter.Name, result);
+                }
+            }
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
+    }
+}