Prepare connection

In order to call remote enabled ABAP function module (ABAP RFM), first a connection must be opened. The connection settings have to be build from a string/string dictionary, for example from a ConfigurationBuilder.

var configurationBuilder =
    new ConfigurationBuilder();

configurationBuilder.AddUserSecrets<Program>();
var config = configurationBuilder.Build();

var settings = new Dictionary<string, string>
{
    {"ashost", config["saprfc:ashost"]},
    {"sysnr", config["saprfc:sysnr"]},
    {"client", config["saprfc:client"]},
    {"user", config["saprfc:username"]},
    {"passwd", config["saprfc:password"]},
    {"lang", "EN"}

};

Calling ABAP Function Modules

We provide a extension method on the RFCContext that supports a syntax similar to the ABAP call function command, except that it is using function callbacks to pass or retrieve data:

• IMPORTING parameters are passed in the Input function
• EXPORTING parameters are retured in the Output function
• CHANGING and TABLES parameters can be used in both functions

• using (var context = new RfcContext(connFunc))
  {
      await context.CallFunction("DDIF_FIELDLABEL_GET",
              Input: f => f
                  .SetField("TABNAME", "USR01")
                  .SetField("FIELDNAME", "BNAME"),
              Output: f => f
                  .GetField<string>("LABEL"))
  
          // this is from language.ext to extract the value from a either
          .Match(r => Console.WriteLine($"Result: {r}"), // should return: User Name
              l => Console.WriteLine($"Error: {l.Message}"));
  }

  Structures

• Structures can be set or retrieved the same way. Another example extracting company code details (you may have to change the company code if you try this example):

• using (var context = new RfcContext(connFunc))
  {
      await context.CallFunction("BAPI_COMPANYCODE_GETDETAIL",
              Input: f => f
                  .SetField("COMPANYCODEID", "1000"),
              Output: f => f
                  .MapStructure("COMPANYCODE_DETAIL", s=> s
                      .GetField<string>("COMP_NAME"))
          )
          .Match(r => Console.WriteLine($"Result: {r}"),
              l => Console.WriteLine($"Error: {l.Message}"));
  
  }

  Alternatively, you can also use a LINQ syntax:

• using (var context = new RfcContext(connFunc))
  {
      await context.CallFunction("BAPI_COMPANYCODE_GETDETAIL",
          Input: f => f
              .SetField("COMPANYCODEID", "1000"),
          Output: f => f
              .MapStructure("COMPANYCODE_DETAIL", s =>
                  from name in s.GetField<string>("COMP_NAME")
                  select name
              ))
  
              .Match(r => Console.WriteLine($"Result: {r}"),
                  l => Console.WriteLine($"Error: {l.Message}"));
  
  }

• Tables

  Getting table results is possible by iterating over the table rows to retrieve the table structures. Here an example to extract all company code name and descriptions:

• using (var context = new RfcContext(connFunc))
  {
      await context.CallFunction("BAPI_COMPANYCODE_GETLIST",
              Output: f => f
                  .MapTable("COMPANYCODE_LIST", s =>
                      from code in s.GetField<string>("COMP_CODE")
                      from name in s.GetField<string>("COMP_NAME")
                      select (code, name)))
          .Match(
              r =>
              {
                  foreach (var (code, name) in r)
                  {
                      Console.WriteLine($"{code}\t{name}");
                  }
              },
              l => Console.WriteLine($"Error: {l.Message}"));
  
  }

• Input mapping

  For Input (importing / changing ) arguments you can pass the value with the methods SetField, SetStructure and SetTable or a combination of all. For example to set values for a table you pass a IEnumerable to be processed to the SetTable method and provide a mapping function for each record in the IEnumerable:

• var userNamesSearch = new string[] {"A*", "B*", "C*"};
  
  var userList = await context.CallFunction("BAPI_USER_GETLIST",
      Input:f => f.SetTable("SELECTION_RANGE", userNamesSearch , 
          (structure,userName) => structure
                  .SetField("PARAMETER", "USERNAME")
                  .SetField("SIGN", "I")
                  .SetField("OPTION", "CP")
                  .SetField("LOW", userName)
          ),
  
      Output: f=> f.MapTable("USERLIST", s=>s.GetField<string>("USERNAME"))
  ).IfLeftAsync(l=>throw new Exception(l.Message));
  
  foreach (var userName in userList)
  {
      Console.WriteLine(userName);
  }

  运用案例：

• 1. 出参中既有单个元素，又有结构：

• using (var context = GetRfcContext())
  {
      await context.CallFunction("ZHR_PLM_GET_MAT_CODE_FERT",
          Input: f => f
              .SetField("I_MATTYPE", I_MATTYPE)
              .SetField("I_STARTWITH", I_STARTWITH),
  
          Output: f =>
          {
              var returnmatnr = f.GetField<string>("EX_MATNR");
              matcode_fert_bysap.returnmatnr = ((RightCase<RfcErrorInfo, string>)returnmatnr.Case).Value;
              return f.MapStructure("EX_RETURN", s =>
              from typ in s.GetField<string>("TYPE")
              from msg in s.GetField<string>("MESSAGE")
              select new { typ = typ, msg = msg }
              );
          })
          .Match(
              r =>
              {
                  matcode_fert_bysap.flg = r.typ;
                  matcode_fert_bysap.msg = r.msg;
              }
              ,
              l =>
              {
                  matcode_fert_bysap.returnmatnr = "";
              }
              );
  }

  2.  出参中既有结构类型变量，又有表类型变量

• using (var context = GetRfcContext())
  {
      await context.CallFunction("ZHR_PLM_GET_MAT_CODE_ROH",
          Input: f => f
              .SetField("I_BIGTYPECODE", i_bigtypecode)
              .SetField("I_SMALLTYPECODE", i_smalltypecode)
              .SetField("I_LIUSHUI_NO", i_liushui_no),
          Output: f =>
          {
              var strut = f.MapStructure("EX_RETURN", s =>
              from typ in s.GetField<string>("TYPE")
              from msg in s.GetField<string>("MESSAGE")
              select new SAP_OUT_RESULT { type = typ, message = msg }
              );
              var val = ((RightCase<RfcErrorInfo, SAP_OUT_RESULT>)strut.Case).Value;
              param.flg = ((dynamic)val).type;
              param.msg = ((dynamic)val).message;
              return f.MapTable("IT_ZMAKT", s =>
              from matnr in s.GetField<string>("MATNR")
              select matnr
              );
          })
          .Match(
              r =>
              {
                  foreach (var matnr in r)
                  {
                      sap_matnr_lst.Add(new sap_matnr()
                      {
                          matnr = matnr,
                          from = "TP"
                      });
                  }
              }
              ,
              l =>
              {
                  param.flg = "E";
              }
              );
  }