Problem with addToJavaScriptWindowObject and JS throwing errors



  • Hello,
    I'm trying to add errors thrown from my cpp objects exposed to JS.
    Here's an example

    @JSObject::JSObject(QWebFrame *p_frame, QObject *parent) :
    QObject(parent)
    {
    frame = p_frame;
    this->setObjectName("MyAPI");
    AttachObject();
    connect( frame, SIGNAL(javaScriptWindowObjectCleared()), this, SLOT(AttachObject()) );
    connect(this,SIGNAL(MyError()),this,SLOT(HandleMyError()));
    }
    QString JSObject::TestMethod()
    {
    //logic here, let's assume something went wrong
    qDebug("test method called, emmiting signal");
    emit MyError();
    qDebug("emit finished, method returning now");
    return "method finish";
    }

    void JSObject::AttachObject()
    {
    this->frame->addToJavaScriptWindowObject(this->objectName(),this);
    }
    void JSObject::HandleMyError()
    {
    QString l_js ="alert('throwing error'); throw new Error();";
    qDebug("evaluating javascript throw error");
    frame->evaluateJavaScript(l_js);
    qDebug("throw error call finished");
    return;
    }@

    and the html:
    @<html>
    <head>
    <title> Error throwing test</title>
    [removed]

    function test()
    {
    try
    {
    var result = MyAPI.TestMethod(); //this should throw an error
    alert(result);
    }
    catch(e)
    {
    alert("error cought");
    }
    return;
    }
    [removed]
    </head>
    <body>
    <button>Test</button>
    </body>

    </html>@
    The alert set here:
    @QString l_js ="alert('throwing error'); throw new Error();"; @
    happens when expected, i get this output:
    test method called, emmiting signal
    evaluating javascript throw error
    //alert happens here, untill i press ok there is no more output, execution stops and waits for alert window to close
    throw error call finished
    emit finished, method returning now

    So I know throw error is executed at the right time, but something is wrong, JS try/catch does not catch it.
    Anybody knows of a good way to add JS errors to exposed cpp objects?



  • I think you basically have the same problem as I do ("see here":http://developer.qt.nokia.com/forums/viewthread/6881/ ).

    The eval() trick does not work (I guess) because errors thrown inside the eval() are not passed to the calling JavaScript context.

    If perhaps you did find a solution in the meantime, then please let me know, thanks!


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