RFCs with multi-nested parameters

From Theobald Software

German Version: Bausteine mit mehrfach verschachtelten Parametern

99% of all RFC enabled function modules / BAPIs consist of scalar or structured imports / exports and of table parameters. But there's also an option to define more complex parameters. This article shows how to handle multi-nested parameters with ERPConnect.

Sample Scenario

In the following sample we use the function module Z_T_CREATE_MULTI_ORDERS. This function is able to create multiple orders per call. The function adds the order number to each order passed and returns all orders back to the caller.

All orders to be created are passed within one single parameter named IN_ORDERS. The export parameter containing the processed orders is named OUT_ORDERS.

Z_T_CREATE_MULTI_ORDERS Import-Parameter

Z_T_CREATE_MULTI_ORDERS Export-Parameter

The table type ZTORDERS contains a list of orders. A single order is represented by the structure ZTORDER. Besides the scalar elements for the customer's number and the order number there is an additional element ZTITEMS. ZTITEMS is again a table type that holds multiple instances of ZTITEM. A sigle instance of ZTITEM represents a single order line.

Just imagine a tree: A list of orders and each order has an unlimited number of items.

ZTORDERS

ZTORDER

ZTITEMS

ZTITEM

XML Coding

If IN_ORDERS was a simple structure it would be no problem to handle it with an RFCStructure object. Even a table-like parameter could be handled by calling the ToTable() method. In case of our sample scenario we need an XML object to handle all elements of the order parameter.

Within the XML a single element is addressed by its name. If there are multiple rows, each row is separated by an <item> tag. The following XML shows a sample of the order parameter. It is a single order with two order lines (ORDERITEMS).

<IN_ORDERS>
  <item>
    <ORDERNO>4711</ORDERNO>
    <CUSTNO>00571020</CUSTNO>
    <ORDERITEMS>
      <item>
        <MATNR>100-100</MATNR>
        <QUANTITY>12.230</QUANTITY>
      </item>
      <item>
        <MATNR>100-200</MATNR>
        <QUANTITY>45.670</QUANTITY>
      </item>
    </ORDERITEMS>
  </item>
</IN_ORDERS>

Coding in C#

This sample code shows how to build the XML shown above by using a StringBuilder and a XmlWriter object. But this is only one under lots of options to do this.

// Create XML document with StringBuilder
// and XmlWriter
StringBuilder MyXML = new StringBuilder();
XmlWriter writer = XmlTextWriter.Create(MyXML);
writer.WriteStartDocument(true);
writer.WriteStartElement("IN_ORDERS");
writer.WriteStartElement("item");
 
writer.WriteElementString("CUSTNO", "00571020");
 
// create first order item
writer.WriteStartElement("ORDERITEMS");
writer.WriteStartElement("item"); // Begin item
writer.WriteElementString("MATNR", "100-100");
writer.WriteElementString("QUANTITY", "12.23");
writer.WriteEndElement(); // End item
 
// create second order item
writer.WriteStartElement("item"); // Begin item
writer.WriteElementString("MATNR", "100-200");
writer.WriteElementString("QUANTITY", "45.67");
writer.WriteEndElement(); // End item
writer.WriteEndElement(); // End ORDERITEMS
 
// close header tags
writer.WriteEndElement(); // End item
writer.WriteEndElement(); // End OUT_ORDER
writer.WriteEndDocument();
writer.Close();

Here you can see how to use ERPConnect and how to assign the XML string.

R3Connection con = new R3Connection(...)
 
con.Open();
RFCFunction func = con.CreateFunction("Z_T_CREATE_MULTI_ORDERS");
func.Exports["IN_ORDERS"].ParamValue = MyXML.ToString();;
func.Execute();

In the sample scenario the function returns the same structure as output parameter. The follwoing sample shows how to generate an XmlDocument object out of the XML string and how to find the order numbers by using an XPath statement (SelectNodes...).

XmlDocument outorder = new XmlDocument();
outorder.LoadXml(func.Imports["OUT_ORDERS"].ParamValue.ToString());
XmlNodeList MyOrderList = outorder.SelectNodes("/OUT_ORDERS/item/*");
 
for (int i = 0; i < MyOrderList.Count; i++)
{
    if (MyOrderList[i].Name.Equals("ORDERNO"))
        Console.WriteLine("Order created: " + MyOrderList[i].InnerText );
}

Coding in VB

If you like VB more than C# here's the code in VB:

' Create XML document with StringBuilder
' and XmlWriter
Dim MyXML As StringBuilder =  New StringBuilder() 
Dim writer As XmlWriter =  XmlTextWriter.Create(MyXML) 
writer.WriteStartDocument(True)
writer.WriteStartElement("IN_ORDERS")
writer.WriteStartElement("item")
writer.WriteElementString("CUSTNO", "00571020")
 
' create first order item
writer.WriteStartElement("ORDERITEMS")
writer.WriteStartElement("item") ' Begin item
writer.WriteElementString("MATNR", "100-100")
writer.WriteElementString("QUANTITY", "12.23")
writer.WriteEndElement() ' End item
 
' create second order item
writer.WriteStartElement("item") ' Begin item
writer.WriteElementString("MATNR", "100-200")
writer.WriteElementString("QUANTITY", "45.67")
writer.WriteEndElement() ' End item
writer.WriteEndElement() ' End ORDERITEMS
 
' close header tags
writer.WriteEndElement() ' End item
writer.WriteEndElement() ' End OUT_ORDER
writer.WriteEndDocument()
writer.Close()

Dim con As R3Connection =  New R3Connection(...) 
 
con.Open()
Dim func As RFCFunction =  con.CreateFunction("Z_T_CREATE_MULTI_ORDERS") 
func.Exports("IN_ORDERS").ParamValue = MyXML.ToString()
func.Execute()

Dim outorder As XmlDocument =  New XmlDocument() 
outorder.LoadXml(func.Imports("OUT_ORDERS").ParamValue.ToString())
Dim MyOrderList As XmlNodeList =  outorder.SelectNodes("/OUT_ORDERS/item/*") 
 
Dim i As Integer
For  i = 0 To  MyOrderList.Count- 1  Step  i + 1
    If MyOrderList(i).Name.Equals("ORDERNO") Then
        Console.WriteLine("Order created: " + MyOrderList(i).InnerText)
    End If
Next