Swift

Call a JavaScript Function Passing an Array Argument

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Demonstrates how to call a JavaScript function with an argument that is an array. Swift

func chilkatTest() {
    var success: Bool = false

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

    //  function calculateTotal(numbers) {
    //    console.log(numbers);
    //    let total = 0;
    //    
    //    // Loop through every number in the array
    //    for (const num of numbers) {
    //      console.log(num);
    //      total += num;
    //    }
    //    
    //    return total;
    //  }

    let sbScript = CkoStringBuilder()!
    success = sbScript.loadFile(path: "js_function_array_arg.js", charset: "utf-8")
    if success == false {
        print("\(sbScript.lastErrorText!)")
        return
    }

    let js = CkoJs()!

    let result = CkoJsonObject()!
    result.emitCompact = false

    //  Call Eval to add the function to the context's global object
    success = js.eval(jscript: sbScript, result: result)
    if success == false {
        //  Examine the result for an exception.
        print("\(result.emit()!)")

        //  Also examine the LastErrorText.
        print("\(js.lastErrorText!)")
        return
    }

    //  ------------------------------------------------------------------------------
    //  Call the function calculateTotal(numbers)

    let funcCall = CkoJsonObject()!
    funcCall.emitCompact = false

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

    funcCall.updateString(jsonPath: "name", value: "calculateTotal")

    //  Create the arguments array.
    let argsArray = CkoJsonArray()!

    //  The 1st argument in the arguments array is itself an array.
    //  Passing -1 indicates to append to the array.
    let arg = CkoJsonArray()!
    argsArray.addArrayAt2(index: -1, jarr: arg)

    //  Fill in the values for the 1st argument.
    arg.addNumber(at: -1, numericStr: "10.50")
    arg.addNumber(at: -1, numericStr: "20.00")
    arg.addNumber(at: -1, numericStr: "5.25")

    //  Add the "args" array to the funcCall.
    funcCall.appendArrayCopy(name: "args", jarr: argsArray)

    print("\(funcCall.emit()!)")

    //  The funcCall is as follows.  Notice that the 1st (and only) argument is an array.

    //  {
    //    "name": "calculateTotal",
    //    "args": [
    //      [
    //        10.50,
    //        20.00,
    //        5.25
    //      ]
    //    ]
    //  }

    success = js.callFunction(func: funcCall, result: result)
    if success == false {
        //  Examine the result for an exception.
        print("\(result.emit()!)")

        //  Also examine the LastErrorText.
        print("\(js.lastErrorText!)")
        return
    }

    print("\(result.emit()!)")

    //  Result:
    //  {
    //    "type": "double",
    //    "value": 35.75
    //  }

    //  The function also emitted text to the console.

    let sbOut = CkoStringBuilder()!
    js.consoleOutputSb(sb: sbOut)
    print("\(sbOut.getAsString()!)")

    //  Output:
    //  10.5,20,5.25
    //  10.5
    //  20
    //  5.25

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

    funcCall.clear()
    funcCall.updateString(jsonPath: "name", value: "calculateTotal")
    funcCall.updateNumber(jsonPath: "args[0][0]", numericStr: "10.50")
    funcCall.updateNumber(jsonPath: "args[0][1]", numericStr: "20.00")
    funcCall.updateNumber(jsonPath: "args[0][2]", numericStr: "5.25")
    print("\(funcCall.emit()!)")

}

JavaScript

function calculateTotal(numbers) {
  console.log(numbers);
  let total = 0;
  
  // Loop through every number in the array
  for (const num of numbers) {
    console.log(num);
    total += num;
  }
  
  return total;
}