---
title: Opening A UI In A Popup Window
order: 79
layout: page
---

[[opening-a-ui-in-a-popup-window]]
= Opening a UI in a popup window

To open a new popup window in the browser showing another part of your
application, you can use the new `BrowserWindowOpener` extension. Any
component or `MenuItem` that you extend with `BrowserWindowOpener` will make clicking
the component open a new browser window with some options for the
content. Opening a popup this way helps you bypass most popup blockers.

One of the things that `BrowserWindowOpener` can be configured to open
in the new window is a new instance of a Vaadin UI class.

[source,java]
....
public class OpeningUIInPopup extends UI {
  @Override
  protected void init(VaadinRequest request) {
    Button popupButton = new Button("Open popup with MyPopupUI");

    BrowserWindowOpener popupOpener = new BrowserWindowOpener(MyPopupUI.class);
    popupOpener.setFeatures("height=300,width=300");
    popupOpener.extend(popupButton);

    // Add a parameter
    popupOpener.setParameter("foo", "bar");

    // Set a fragment
    popupOpener.setUriFragment("myfragment");

    setContent(popupButton);
  }
}

public class MyPopupUI extends UI {
  @Override
  protected void init(VaadinRequest request) {
    setContent(new Label("This is MyPopupUI where parameter foo="
        + request.getParameter("foo") + " and fragment is set to "
        + getPage().getUriFragment()));
  }
}
....

In this example, a `Button` is created and extended with a
`BrowserWindowOpener`. Furthermore, the size of the popup window is
defined. See
https://developer.mozilla.org/en-US/docs/DOM/window.open#Position_and_size_features
for a description of the commonly supported features. If you don't
define any features, the browser will use its default setting which
usually makes it open a new tab instead of opening a popup window.

The `BrowserWindowOpener` can also be used to open a `Resource` or any
URL that you define using different constructors.