Qt QWEBview JavaScript callback

javascript qt qwebview slot
user457015 picture user457015 · Feb 12, 2011 · Viewed 17.6k times · Source

How to pass a function "pointer" from JavaScript to a slot?

in JavaScript:

function f1()
{
    alert("f1");
}
qtclass.submit(f1);

and in Qt:

public slots:
    void submit(void * ptr) 
    {
        (void)ptr;
    }

I need the "f1", function to get fired in the JavaScript from the c++, once some processing is done. Also I do not know in advance the name of the function pointer.

Answer

serge_gubenko picture serge_gubenko · Feb 12, 2011

you should be able to execute your script using QWebFrame::evaluateJavaScript method. See if an example below would work for you:

initializing webview: 

QWebView *view = new QWebView(this->centralWidget());
view->load(QUrl("file:///home//test.html"));
connect(view, SIGNAL(loadFinished(bool)), this, SLOT(loadFinished(bool)));

loadFinished signal handler:

void MyTestWindow::loadFinished(bool)
{
    QVariant f1result = ((QWebView*)sender())->page()->mainFrame()->evaluateJavaScript("f1('test param')");
    qDebug() << f1result.toString();
}

test.html:

<head>
    <script LANGUAGE="JavaScript">
        function f1 (s) 
        {
            alert (s) 
            return "f1 result"
        }
    </script>
</head>
<body>
    test html
</body>

evaluateJavaScript should trigger an alert message box and return QVariant with f1 function result.

hope this helps, regards

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