C#

Call a JavaScript Function Passing an Object Argument

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Demonstrates how to call a JavaScript function with an argument that is an object. C#

bool success = false;

//  This is the JavaScript function we'll call:

//  function describeCar(car) {
//  	console.log(`This is a ${car.year} ${car.make} ${car.model}.`);
//  }

Chilkat.StringBuilder sbScript = new Chilkat.StringBuilder();
sbScript.Append("function describeCar(car) { console.log(`This is a ${car.year} ${car.make} ${car.model}.`); }");

Chilkat.Js js = new Chilkat.Js();

Chilkat.JsonObject result = new Chilkat.JsonObject();
result.EmitCompact = false;

//  Call Eval to add the function to the context's global object
success = js.Eval(sbScript,result);
if (success == false) {
    //  Examine the result for an exception.
    Debug.WriteLine(result.Emit());

    //  Also examine the LastErrorText.
    Debug.WriteLine(js.LastErrorText);
    return;
}

//  ------------------------------------------------------------------------------
//  Call the function describeCar(car)

Chilkat.JsonObject funcCall = new Chilkat.JsonObject();
funcCall.EmitCompact = false;

//  Create JSON specifying the function name and arguments
//  In this case, there is only 1 argument, and it is an object.

//  {
//    "name": "describeCar",
//    "args": [
//      {
//        "make": "Toyota",
//        "model": "Corolla",
//        "year": 2022
//      }
//    ]
//  }

funcCall.UpdateString("name","describeCar");

//  Create the JSON object that is the argument.
Chilkat.JsonObject arg = new Chilkat.JsonObject();
arg.UpdateString("make","Toyota");
arg.UpdateString("model","Corolla");
arg.UpdateInt("year",2022);

//  Create the arguments array.
Chilkat.JsonArray argsArray = new Chilkat.JsonArray();
argsArray.AddObjectCopyAt(0,arg);

//  Add the "args" array to the funcCall.
funcCall.AppendArrayCopy("args",argsArray);

Debug.WriteLine(funcCall.Emit());

success = js.CallFunction(funcCall,result);
if (success == false) {
    //  Examine the result for an exception.
    Debug.WriteLine(result.Emit());

    //  Also examine the LastErrorText.
    Debug.WriteLine(js.LastErrorText);
    return;
}

Debug.WriteLine(result.Emit());

//  The describeCar JavaScript function returns nothing. 
//  Therefore, the result is "undefined".

//  {
//    "type": "undefined",
//    "value": "undefined"
//  }

//  However, the function emitted text to the console.

Chilkat.StringBuilder sbOut = new Chilkat.StringBuilder();
js.ConsoleOutputSb(sbOut);
Debug.WriteLine(sbOut.GetAsString());

//  Output:
//  This is a 2022 Toyota Corolla.

//  -----------------------------------------------------------
//  Note: If the object argument is simple, this is an alternative
//  and simpler way of creating the funcCall:

funcCall.Clear();
funcCall.UpdateString("name","describeCar");
funcCall.UpdateString("args[0].make","Toyota");
funcCall.UpdateString("args[0].model","Corolla");
funcCall.UpdateInt("args[0].year",2022);
Debug.WriteLine(funcCall.Emit());