Edge: Calling node.js from .net

[harivasista]

I tried asking this question on slack but didn't get a response. Hence asking it here, apologies for that.

I need to notify the node.js application(electron in my case) when something happens in the .net code. How can I achieve that ?

[garysmi2]

I have no relation to this repo. but I can tell you how I do it using electron-edge with an Electron app I have. C# code is loaded as a DLL, running on windows only.

1. Bind the functions in the DLL in electron

let assemblyFile = __dirname + "/my.dll" //path to DLL, I'm simply storing the DLL in the current electron directory

const init = edge.func({
    assemblyFile : assemblyFile,
    typeName: 'MyNameSpace.MyClassName',
    methodName: 'InitCallbacks'   // I have a method in my MyClassName called this
});

1. I create a javascript object with the functions I want to be called one way from the C# code

app.on('ready', () => {

...
const registerCallbacks = {
    function1 : (data) => {
           //doSomething with data
          console.log(data);
         },
    function2: (data) => {
        //doSometing with data
      console.log(data);
     }
    //and so on
    };
   //call the c# init  function passing in the object with the javascript functions
   init(registerCallBacks);
...
};

1. In c# MyClass

public class MyClass {
 ...
 private Func<object, Task<object>> function1;
 private Func<object, Task<object>> function2;
 ...

 public async Task<object> InitCallbacks(dynamic input)
{
    return await Task.Run<object>(() =>
    {
                IDictionary<string, object> callbackFunctions = (IDictionary<string, object>)input;
               //assign the electron function to the class variable, 
                function1 = (Func<object, Task<object>>)callbackFunctions["function1"];
                function2 = (Func<object, Task<object>>)callbackFunctions["function2"];
                return new { };
       });

   }

}

I can then use function1, function2 in the c# code to call back to electron any time

if(function1 != null){
    await function1(someData);
}

[harivasista]

@garysmi2 I have a function which returns some response from the WCF service. How do I map with the delegate function that you have declared ?
For eg:

public static string Response()
   {
      returns response;
   }

I need to map this function to function1. How do I do it ?

[garysmi2]

I wouldn't try map it. I'd call function1 passing in the result from Response() as a parameter. Probably lots of ways to do this

public async void GetSomeValue()
{
    string response = Response();

    //pass the result to electron/node
   if(function1 != null)
  {
        await function1(response);
  }
}

[harivasista]

It worked for me thank you :)