QJSEngine add custom object

TheHawk

Hi,

I am trying to use a script to plot a graph in my program.
I am using QCustomPlot and it works fine if used in my C++ code.
However, if I pass the QCustomPlot to the QJSEngine like this:

QJSEngine myEngine;
QCustomPlot *graph = new QCustomPlot;
QJSValue scriptgraph = myEngine.newQObject(graph);
myEngine.globalObject().setProperty("graph",scriptgraph);

And my script looking like this:

graph.addGraph();
graph.xAxis.setLabel("TESTX");
graph.yAxis.setLabel("TESTY");
graph.replot();

The QJSEngine will throw the following error:
result: 1 : "ReferenceError: addGraph is not defined"

Which makes me think that the object is passes but not the classes it has. Am I missing something here?

Thanks!

t3685

@TheHawk

Hi,

You need to show your QCustomPlot class. Did you add the Q_INVOKABLE macro in front of your addGraph() function?

Greetings,

t3685

TheHawk

@t3685

The QCustomPlot is from internet. And no, I did not add Q_Invokable to the functions of QCustomPlot. I can try and see if this fixes the error. Thanks!

Edit: tried Q_INVOKABLE QCPGraph *addGraph(QCPAxis *keyAxis=0, QCPAxis *valueAxis=0); without succes.

t3685

@TheHawk

Hi,

What error are you getting? Did you rerun qmake to regenerate the moc_*.cpp files?

Greetings,

t3685

TheHawk

@t3685
Hi,

I am getting: result: 1 : "ReferenceError: addGraph is not defined" with my script looking like:

	graph.addGraph();
	graph.xAxis.setLabel("TESTX");
	graph.yAxis.setLabel("TESTY");
	graph.replot();

and wrapping the graph like this:

    QCustomPlot *graph = new QCustomPlot;
    ui->verticalLayout->addWidget(graph);
    QJSValue scriptgraph = myEngine.newQObject(graph);
    myEngine.globalObject().setProperty("graph",scriptgraph);

And yes, I cleaned, reran Qmake and even rebuild everything but without succes.

Am I running into a limitation of QJSEngine? If so, what would be the wisest thing for me to do? I would really like to access objects like the above, if that is not possible, would QTQuick with QML be anything for me? If I read this it looks like that what I am trying to achieve is relatively simple in QML with QtQuick. However, I do not have QtQuick installed at the moment so I would have to rewrite all my existing code to use the import "script.js" as scipt function, correct? If not, how would this be done in my Qt Creator project?

Thanks! :)

t3685

@TheHawk

Hi,

How are you invoking your script? As in how are you calling "script.js". Are you calling it using "myEngine"? If yes, can you show that code?

Greetings,

t3685

TheHawk

@t3685
Hi,

I am calling it like this:

    QString fileName = "customlogic.qs";
    QFile scriptFile(fileName);
    if (!scriptFile.open(QIODevice::ReadOnly))
    {
    }// handle error

    QTextStream stream(&scriptFile);
    QString contents = stream.readAll();
    scriptFile.close();
    QJSValue result = myEngine.evaluate(contents, fileName);
    if (result.isError())
    {
        qDebug() << "result: " << result.property("lineNumber").toInt() << ":" << result.toString();
    }

thanks!

t3685

@TheHawk

Have you tried giving argument to addGraph()? I don't remember whether the default argument translate well to javascript. If that still doesn't work, you can try to make add a dummy QObject class with Q_INVOKABLE functions to your engine to see if the problem is in your code or some possible interaction with QCustomPlot