Custom NodeModel Error: Dereferencing a non-pointer

Developers
1

Hello,
I’m attempting to create a very simple custom NodelModel, but with no success, an Error: Dereferencing a non-pointer keeps apperaing. Dynamo version: 1.0.0.1180.

If no input is connected, the node shows gray as normal, but if two numbers are connected as input I get:

I’ve been following the same structure of other Dynamo nodes, so I cannot explain myself what’s wrong or missing. The node simply multiplies two numbers, below the full code:

using System;
using System.Collections.Generic;
using Dynamo.Graph.Nodes;
using ProtoCore.AST.AssociativeAST;

namespace TestNodeModel
{
  [NodeDescription("Test Node")]
  [NodeName("TestNode")]
  [NodeCategory("TestCategory")]
  [InPortNames("A", "B")]
  [InPortTypes("double", "double")]
  [InPortDescriptions("Number A", "Numnber B")]
  [OutPortNames("Output")]
  [OutPortTypes("double")]
  [OutPortDescriptions("AxB")]
  [IsDesignScriptCompatible]
  public class TestNodeModel : NodeModel
  {
    public TestNodeModel()
    {
      RegisterAllPorts();
    }

    public override IEnumerable<AssociativeNode> BuildOutputAst(List<AssociativeNode> inputAstNodes)
    {
      if (!HasConnectedInput(0) || !HasConnectedInput(1))
      {
        return new[] { AstFactory.BuildAssignment(GetAstIdentifierForOutputIndex(0), AstFactory.BuildNullNode()) };
      }

      var functionCall =
        AstFactory.BuildFunctionCall(
          new Func<double, double, double>(DoCalc),
          new List<AssociativeNode> { inputAstNodes[0], inputAstNodes[1] });

      return new[] { AstFactory.BuildAssignment(GetAstIdentifierForOutputIndex(0), functionCall) };
    }

    public static double DoCalc(double a, double b)
    {
      return a * b;
    }
  }
}
2

Disclaimer: I know practically no C#

However, built a dll using the exact same code posted above and imported it in the latest daily build (1.1)
Worked for me.

3

Vikram, thanks for your help.
It looks like you have loaded the dll as a ZeroTouch node and accessed the DoCalc method diretly, while I’m testing it as a NodeModel for which you need the whole package.

I’ve attached a copy of it if you want to test: https://www.dropbox.com/s/ultjbotv57p02sp/TestNodeModel.zip?dl=0

4

SOLUTION from Ian: the DoCalc method has to be in a separate assembly.

2 Likes
5

Sharing a repo containing the source code fore those interested: https://github.com/teocomi/HelloDynamo
The separate assembly has to be loaded into dynamo directly, so it has to be declared the pkg.json file as well.

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