Myujth

I have a very vague understanding of WCF but after a bit of research I figured out that WCF does not like handling custom objects. I am looking for a feasible workaround.

This is my objective.
I aim to create a WCF service that accepts certain values from a client machine, sends them to the server where it invokes an R instance and executes a set of DataFrame transformations and return the resulting DataFrame. DataFrames seem to be in the format of a vector / 2D array.
The error I am getting is:
the operation is not supported in wcf because it uses type system.object

see example code below -

 public string R_to_SQLstring_InsertTable(string table_name, DataFrame Table)
 
 string query2 = "INSERT INTO table_name (";

 for (int x = 0; x < Table.ColumnCount; x++)
 
 if (x == (Table.ColumnCount) - 1)
 
 query2 = query2 + Table.Names[x] + "";
 
 else
 
 query2 = query2 + Table.Names[x] + ", ";
 

 
 query2 = query2 + ") Values (";


 for (int count1 = 0; count1 < Table.RowCount; count1++)
 
 for (int count2 = 0; count2 < Table.ColumnCount; count2++)
 
 if (count2 == (Table.ColumnCount) - 1)
 
 query2 = query2 + " " + Table[count2][count1];
 
 else
 
 query2 = query2 + " " + Table[count2][count1] + ",";
 

 

 if (count1 == (Table.RowCount) - 1)
 
 query2 = query2 + ");";
 
 else
 
 query2 = query2 + "), (";
 

 
 return query2;
 



 public DataFrame R_Transformation_MergeTable(string tableloca1, string tableloca2)
 

 StartupParameter rinit = new StartupParameter();
 rinit.Quiet = true;
 rinit.RHome = @"C:Program FilesRR-3.4.4";
 rinit.Home = @"C:R";
 REngine.SetEnvironmentVariables();
 REngine engine = REngine.GetInstance(null, true, rinit);

 try
 
 engine.Evaluate("Table1 <- read.csv(file='" + tableloca1+")");
 engine.Evaluate("Table2 <- read.csv(file='" + tableloca2 + ")");

 DataFrame Table = engine.Evaluate("Merge <- merge(Table1,Table2)").AsDataFrame();
 return Table;
 
 catch (Exception x)
 

 throw new Exception("Please Upload .CSV file");

 


 

I pass generic objects over WCF by manually serializing them to byte and passing in the type definition (as a string, Type cannot go over WCF either) then casting it back to the proper type using reflection. Given an object, you may have to iterate over it and use reflection to determine the type of each entry for this purpose though.

A better technique if possible would be to cast the objects to a data contract type before sending them over the service.