Question

I’d like to know how to call a GWT static method from the parent of the iframe in which the gwt module is loaded.

As a simple example suppose I have the following gwt class:

public class Simple {
    public static void showWindow() {
        Window.alert("Hello from the iframe");
    }
}

I create an html host page called “iFrameHost.html” that can run the function above. Then in an unrelated GWT module on a different page I call:

Frame iFrame = new Frame("iFrameHost.html");
RootPanel.get().add(iFrame);

How do I now call the showWindow() method from the parent page?

Answer 1

This is based on Gipsy King’s answer:

Simple Class becomes:

public class Simple {
    public static void showWindow() {
        Window.alert("Hello from the iframe");
    }
    public static final native void setWindowFunction() /*-{
        $wnd.jsniShowWindow = [e-mail]::showWindow();
    }-*/;
}

Then to call the Simple class from the parent HTML page:
Set the IFrame id and use the following method:

 private native void callShowWindow() /*-{
       $doc.getElementById("iFrameID").contentWindow.jsniShowWindow(); 
 }-*/;

You’ll have to make certain that the iFrame page has called setWindowFunction() but after that you can call callShowWindow() from the parent html page.