How to call JavaScript from Java

Question

I'm trying to call a JavaScript function testCheckMate from Java but I get error:

Exception in thread "JavaFX Application Thread" netscape.javascript.JSException: SyntaxError: Unexpected EOF

The WebView is holding FullCalendar.

How do I go about calling JQuery/ Javascript from Java? Thank you all in advance.

<!DOCTYPE html>
<html>
    <head>
        <link href='../fullcalendar/fullcalendar.css' rel='stylesheet' />
        <link href='../fullcalendar/fullcalendar.print.css' rel='stylesheet' media='print' />
        <script src='../lib/jquery.min.js'></script>
        <script src='../lib/jquery-ui.custom.min.js'></script>
        <script src='../fullcalendar/fullcalendar.min.js'></script>
        <script>

            $(document).ready(function() {

                var date = new Date();
                var d = date.getDate();
                var m = date.getMonth();
                var y = date.getFullYear();

                $('#calendar').fullCalendar({
                        editable: true,

                    testCheckMate: function() {
                        alert("Check-Mate");
                    },

                    events: [
                        {
                            title: 'All Day Event',
                            start: new Date(y, m, 1)
                        },
                        {
                            id: 999,
                            title: 'Repeating Event',
                            start: new Date(y, m, d + 4, 16, 0),
                            allDay: false
                        }
                    ]
                });

            });

        </script>
    </head>
    <body>
        <div id='calendar'></div>
    </body>
</html>

score 2 · Accepted Answer · edited May 23 '17 at 10:28

If you want to add a function on the html file you could another <script> tag, or just use the one there, but out of the $(document).ready() jQuery block:

<script>

    function testCheckMate() {
        alert("Check-Mate");
    };

    $(document).ready(function() {
        $('#calendar').fullCalendar({
           ...
        });
    }); 
</script>

Or, as in this answer, you need to declare the name of the function up front:

<script>

    var testCheckMate;

    $(document).ready(function() {

        testCheckMate=function () {
            alert("Check-Mate");
        };

        $('#calendar').fullCalendar({
           ...
        });
    }); 
</script>

Alternatively, as in this answer, you can create your function on the Java side, without the need to modify the html file:

private WebView webView;
private WebEngine engine;

private void createCalendar() {
    webView = new WebView();
    engine = webView.getEngine();
    engine.load("file:D:/standAloneDev//src/fc/fullcalendarwebview/fullcalendar-1.6.4/demos/selectable.html");

    engine.getLoadWorker().stateProperty().addListener((ov,oldState, newState)->{
        if(newState==State.SUCCEEDED){

            // JS to Java
            JSObject script = (JSObject) engine.executeScript("window");
            script.setMember("myClick", new JavaApp());

            // Java to JS
            engine.executeScript("function testCheckMate() {\n" +
                        "            alert(\"Check-Mate\");\n" +
                        "        };");
        }
    });

    engine.setOnAlert(e->System.out.println("Alert: "+e.getData()));
}

and call it on your app:

 @Override
public void start(Stage primaryStage) {
    Button btn=new Button("Call function");
    btn.setOnAction(e->{
         engine.executeScript("testCheckMate();");
    });
    Scene scene = new Scene(new VBox(webView,btn), 600, 400);

    primaryStage.setScene(scene);
    primaryStage.show();
}

In any case, note that the alert window won't be shown in your calendar, since it's trapped by the webView. The setOnAlert() method is used to get the notifications.

How to call JavaScript from Java

1 Answers1