Is it possible to use functions in custom dll that return objects of the model?

[bernatagulloesbrina]

it is a very niche question, so I'll just leave it here in case someone has succeded.

I'm creating custom functions in a custom dll to reuse from tabular editor scripts
I've succeeded creating boolean functions (which can have out parameters, so it's not all lost)
however when I tried creating a funciton that returns a table or calculated table I could not go around the error
"Object Reference Not Set to an instance of an object."

Model.AddCalculatedTable should return a table (or CalculatedTable) object right?

either my lacking tomwrapper knowledge and/or c# knowledge are to blame for this question

this works

public static bool CreateMeasureTable
            (
                Model model, 
                string defaultTableName = "Some Measures"
              )
        {

            string tableExpression = "{0}";

            model.AddCalculatedTable(name: defaultTableName, expression: tableExpression);
            
            return true;

        }

this does not

        public static Table CreateMeasureTable
            (
                Model model,
                string defaultTableName = "Some Measures",
             )
        {

            string tableExpression = "{0}";

            return model.AddCalculatedTable(name: defaultTableName, expression: tableExpression);

            

        }

am I doing something wrong?

I might stick with the boolean approach, but wondering if in some cases I could do the object approach

[otykier]

I think the error you're seeing originates from the outer script that calls into your custom dll. Could you share that script here as well?

[bernatagulloesbrina]

Sure,

it's something like this. I tried with Table and CalculatedTable

#r "C:\Users\ESAgulloBe\OneDrive - NESTLE\AAA Repo\ExtendedTOMWrapper\bin\x64\Debug\ExtendedTOMWrapper.dll"

using ExtendedTOMWrapper; 


Table t = Model.AddCalculatedTable(name: "myName2", expression: "{0}");
Output(t.Name);

[otykier]

But in that code, you're not using the CreateMeasureTable method from your dll?

[bernatagulloesbrina]

oups! apologies, here's the code

#r "C:\Users\ESAgulloBe\OneDrive - NESTLE\AAA Repo\ExtendedTOMWrapper\bin\x64\Debug\ExtendedTOMWrapper.dll"

using ExtendedTOMWrapper; 

string myName;
CalculatedTable myTable = TableUtils.CreateMeasureTable(defaultTableName:"myMeasureTable",model:Model);

[otykier]

Looks good to me (assuming TableUtils is the name of the class in which the CreateMeasureTable static method resides).

Maybe try to add some null checks here and there? For example, try to add something like:

if(model == null) throw new ArgumentNullException("model");

just above the line where you call model.AddCalculatedTable in your dll code. You should then see a different error message if the model object does not get correctly passed to CreateMeasureTable.

[bernatagulloesbrina]

Well, I'm not sure what is it, but now I put the null check and it works! (so it was not passing a null, so it should have worked, but whatever)
Thank you for your patience and dedication!