alert box is not working in javascript while validating html form in JAVAFX

Question

i am pretty much new to javafx. i have built an application on javafx which will load index.html page through WebView. when i click on register button in index.html new registration form page will be loaded.

javafx code:

public void start(final Stage primaryStage) throws Exception {
    primaryStage.setResizable(false);
    FrontEndFinal f=new FrontEndFinal();

    final WebView browser = new WebView();
    final WebEngine webEngine = browser.getEngine();
    webEngine.setJavaScriptEnabled(true);
    Worker<Void> worker = webEngine.getLoadWorker();
    worker.stateProperty().addListener(new ChangeListener<State>() {

        public void changed(ObservableValue<? extends State> observable, //
                State oldValue, State newValue) {

            // When load successed.
            if (newValue == Worker.State.SUCCEEDED) {

                JSObject jsobj = (JSObject) webEngine.executeScript("window");

                jsobj.setMember("myJavaMember", new FrontEndFinal());
            }
        }
    });
    VBox root = new VBox();

    root.setMinHeight(500);
    root.setMinWidth(1250);


    System.out.println(System.getProperty("user.dir"));
    String p=System.getProperty("user.dir");
    String [] t=p.split("\\\\");
    System.out.println(t.length);
    String final1=t[0]+"/";
    for(int i=1;i<t.length;i++)
    {
        final1=final1+t[i]+"/";
    }
    System.out.println(final1);


    browser.getEngine().load("file:///"+final1+"/Html"+"/SMS.html");
    root.getChildren().add(browser); 
}

When I run this code it loads index.html

in Index.html:

<button class="dropbtn"  onclick="location.href = 'Registration.html'"><b>< Register ></b></button>

after clicking button it opens Registration.html

In Registration.html

<form name="myForm"  method="post">
Name: <input type="text" name="fname">
<button type="button" name="Submit" onclick="abc()">Submit</button>
<script>
function abc(){
    window.alert("Invalid name");
}

Now my problem is when i submit Registration.html form with name field blank, it does not shows alert box i googled many sites like:[https://community.oracle.com/thread/2540279] but didn't work Any help or suggestions?

Thanks In Advance

James_D · Accepted Answer · 2017-06-05 11:47:22Z

2

You need to set an onAlert handler on the web engine. This gives you the ability to configure how you want your application to respond to Javascript alert() callbacks. To show a simple dialog message:

webEngine.setOnAlert(event -> {
    Alert alert = new Alert(Alert.AlertType.INFORMATION);
    alert.setContentText(event.getData());
    alert.showAndWait();
});

Here is a SSCCE:

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class WebViewAlertTest extends Application {

    private final String HTML = ""
            + "<html>"
            + "<body>"
            + "<button onclick='alert(\"Javascript Alert\")'>Submit</button>"
            + "</body>"
            + "</html>";

    @Override
    public void start(Stage primaryStage) {
        WebView webView = new WebView();
        WebEngine webEngine = webView.getEngine();
        webEngine.setOnAlert(event -> {
            Alert alert = new Alert(Alert.AlertType.INFORMATION);
            alert.setHeaderText("Message from the web page");
            alert.setContentText(event.getData());
            alert.showAndWait();
        });
        webEngine.loadContent(HTML);

        Scene scene = new Scene(webView, 400, 400);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

edited Jun 5, 2017 at 11:47

answered Jun 2, 2017 at 12:03

James_D

211k16 gold badges312 silver badges345 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

sagnem sagnem Over a year ago

Hi @James_D Thanks for you reply...but when i run above code it shows error saying event cannot be resolved to a variable.

James_D Over a year ago

@sagnemsagnem The code works fine. I added a complete example that you can run.

Collectives™ on Stack Overflow

alert box is not working in javascript while validating html form in JAVAFX

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related