DataFlex

Call a JavaScript Function Passing an Object Argument

See more JavaScript Examples

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

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Variant vSbScript
    Handle hoSbScript
    Handle hoJs
    Variant vResult
    Handle hoResult
    Variant vFuncCall
    Handle hoFuncCall
    Variant vArg
    Handle hoArg
    Variant vArgsArray
    Handle hoArgsArray
    Variant vSbOut
    Handle hoSbOut
    String sTemp1

    Move False To iSuccess

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

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

    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbScript
    If (Not(IsComObjectCreated(hoSbScript))) Begin
        Send CreateComObject of hoSbScript
    End
    Get ComAppend Of hoSbScript "function describeCar(car) { console.log(`This is a ${car.year} ${car.make} ${car.model}.`); }" To iSuccess

    Get Create (RefClass(cComChilkatJs)) To hoJs
    If (Not(IsComObjectCreated(hoJs))) Begin
        Send CreateComObject of hoJs
    End

    Get Create (RefClass(cComChilkatJsonObject)) To hoResult
    If (Not(IsComObjectCreated(hoResult))) Begin
        Send CreateComObject of hoResult
    End
    Set ComEmitCompact Of hoResult To False

    // Call Eval to add the function to the context's global object
    Get pvComObject of hoSbScript to vSbScript
    Get pvComObject of hoResult to vResult
    Get ComEval Of hoJs vSbScript vResult To iSuccess
    If (iSuccess = False) Begin
        // Examine the result for an exception.
        Get ComEmit Of hoResult To sTemp1
        Showln sTemp1

        // Also examine the LastErrorText.
        Get ComLastErrorText Of hoJs To sTemp1
        Showln sTemp1
        Procedure_Return
    End

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

    Get Create (RefClass(cComChilkatJsonObject)) To hoFuncCall
    If (Not(IsComObjectCreated(hoFuncCall))) Begin
        Send CreateComObject of hoFuncCall
    End
    Set ComEmitCompact Of hoFuncCall To 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
    //     }
    //   ]
    // }

    Get ComUpdateString Of hoFuncCall "name" "describeCar" To iSuccess

    // Create the JSON object that is the argument.
    Get Create (RefClass(cComChilkatJsonObject)) To hoArg
    If (Not(IsComObjectCreated(hoArg))) Begin
        Send CreateComObject of hoArg
    End
    Get ComUpdateString Of hoArg "make" "Toyota" To iSuccess
    Get ComUpdateString Of hoArg "model" "Corolla" To iSuccess
    Get ComUpdateInt Of hoArg "year" 2022 To iSuccess

    // Create the arguments array.
    Get Create (RefClass(cComChilkatJsonArray)) To hoArgsArray
    If (Not(IsComObjectCreated(hoArgsArray))) Begin
        Send CreateComObject of hoArgsArray
    End
    Get pvComObject of hoArg to vArg
    Get ComAddObjectCopyAt Of hoArgsArray 0 vArg To iSuccess

    // Add the "args" array to the funcCall.
    Get pvComObject of hoArgsArray to vArgsArray
    Get ComAppendArrayCopy Of hoFuncCall "args" vArgsArray To iSuccess

    Get ComEmit Of hoFuncCall To sTemp1
    Showln sTemp1

    Get pvComObject of hoFuncCall to vFuncCall
    Get pvComObject of hoResult to vResult
    Get ComCallFunction Of hoJs vFuncCall vResult To iSuccess
    If (iSuccess = False) Begin
        // Examine the result for an exception.
        Get ComEmit Of hoResult To sTemp1
        Showln sTemp1

        // Also examine the LastErrorText.
        Get ComLastErrorText Of hoJs To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComEmit Of hoResult To sTemp1
    Showln sTemp1

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

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

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

    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbOut
    If (Not(IsComObjectCreated(hoSbOut))) Begin
        Send CreateComObject of hoSbOut
    End
    Get pvComObject of hoSbOut to vSbOut
    Send ComConsoleOutputSb To hoJs vSbOut
    Get ComGetAsString Of hoSbOut To sTemp1
    Showln sTemp1

    // 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:

    Send ComClear To hoFuncCall
    Get ComUpdateString Of hoFuncCall "name" "describeCar" To iSuccess
    Get ComUpdateString Of hoFuncCall "args[0].make" "Toyota" To iSuccess
    Get ComUpdateString Of hoFuncCall "args[0].model" "Corolla" To iSuccess
    Get ComUpdateInt Of hoFuncCall "args[0].year" 2022 To iSuccess
    Get ComEmit Of hoFuncCall To sTemp1
    Showln sTemp1


End_Procedure