Docs Help

Terms, Icons, and Labels

Many classes have shortcut names used when creating (instantiating) a class with a configuration object. The shortcut name is referred to as an alias (or xtype if the class extends Ext.Component). The alias/xtype is listed next to the class name of applicable classes for quick reference.

Access Levels

Framework classes or their members may be specified as private or protected. Else, the class / member is public. Public, protected, and private are access descriptors used to convey how and when the class or class member should be used.

Member Types

Member Syntax

Below is an example class member that we can disect to show the syntax of a class member (the lookupComponent method as viewed from the Ext.button.Button class in this case).

lookupComponent ( item ) : Ext.Component

Called when a raw config object is added to this container either during initialization of the items config, or when new items are added), or {@link #insert inserted.

This method converts the passed object into an instanced child component.

This may be overridden in subclasses when special processing needs to be applied to child creation.


item :  Object

The config object being added.


The component to be added.

Let's look at each part of the member row:

Member Flags

The API documentation uses a number of flags to further commnicate the class member's function and intent. The label may be represented by a text label, an abbreviation, or an icon.

Class Icons

- Indicates a framework class

- A singleton framework class. *See the singleton flag for more information

- A component-type framework class (any class within the Ext JS framework that extends Ext.Component)

- Indicates that the class, member, or guide is new in the currently viewed version

Member Icons

- Indicates a class member of type config

- Indicates a class member of type property

- Indicates a class member of type method

- Indicates a class member of type event

- Indicates a class member of type theme variable

- Indicates a class member of type theme mixin

- Indicates that the class, member, or guide is new in the currently viewed version

Class Member Quick-Nav Menu

Just below the class name on an API doc page is a row of buttons corresponding to the types of members owned by the current class. Each button shows a count of members by type (this count is updated as filters are applied). Clicking the button will navigate you to that member section. Hovering over the member-type button will reveal a popup menu of all members of that type for quick navigation.

Getter and Setter Methods

Getting and setter methods that correlate to a class config option will show up in the methods section as well as in the configs section of both the API doc and the member-type menus just beneath the config they work with. The getter and setter method documentation will be found in the config row for easy reference.

History Bar

Your page history is kept in localstorage and displayed (using the available real estate) just below the top title bar. By default, the only search results shown are the pages matching the product / version you're currently viewing. You can expand what is displayed by clicking on the button on the right-hand side of the history bar and choosing the "All" radio option. This will show all recent pages in the history bar for all products / versions.

Within the history config menu you will also see a listing of your recent page visits. The results are filtered by the "Current Product / Version" and "All" radio options. Clicking on the button will clear the history bar as well as the history kept in local storage.

If "All" is selected in the history config menu the checkbox option for "Show product details in the history bar" will be enabled. When checked, the product/version for each historic page will show alongside the page name in the history bar. Hovering the cursor over the page names in the history bar will also show the product/version as a tooltip.

Search and Filters

Both API docs and guides can be searched for using the search field at the top of the page.

On API doc pages there is also a filter input field that filters the member rows using the filter string. In addition to filtering by string you can filter the class members by access level, inheritance, and read only. This is done using the checkboxes at the top of the page.

The checkbox at the bottom of the API class navigation tree filters the class list to include or exclude private classes.

Clicking on an empty search field will show your last 10 searches for quick navigation.

API Doc Class Metadata

Each API doc page (with the exception of Javascript primitives pages) has a menu view of metadata relating to that class. This metadata view will have one or more of the following:

Expanding and Collapsing Examples and Class Members

Runnable examples (Fiddles) are expanded on a page by default. You can collapse and expand example code blocks individually using the arrow on the top-left of the code block. You can also toggle the collapse state of all examples using the toggle button on the top-right of the page. The toggle-all state will be remembered between page loads.

Class members are collapsed on a page by default. You can expand and collapse members using the arrow icon on the left of the member row or globally using the expand / collapse all toggle button top-right.

Desktop -vs- Mobile View

Viewing the docs on narrower screens or browsers will result in a view optimized for a smaller form factor. The primary differences between the desktop and "mobile" view are:

Viewing the Class Source

The class source can be viewed by clicking on the class name at the top of an API doc page. The source for class members can be viewed by clicking on the "view source" link on the right-hand side of the member row.

GXT 3.x


GXT FAQ and Evaluation Guide

We've prepared this short guide for customers who are evaluating GXT for a project. If you have additional questions not answered here, we invite you to contact Sales.


Sencha GXT is a comprehensive Java framework for building desktop-like applications that run in a browser. It uses the GWT (formerly Google Web Toolkit) compiler, allowing you to write applications in Java and compile your code into highly optimized cross-platform HTML5 and Javascript code.

Frequently asked questions

Supported versions and browsers

GXT releases work with specific GWT versions.

Development environment

Sencha recommends that GXT developers use one of the following Java IDEs:

  • IntelliJ IDEA Ultimate 13+
  • Eclipse EE (Mars,Kepler) with the Google Plugin for Eclipse. There is also a community GWT Plugin for Eclipse which adds support for running super dev mode on your own server (Tomcat, JBoss, App Engine dev server, etc.) vs. the jetty server only.

Is there a "WYSIWYG" designer tool to create GXT layouts?

Unfortunately, the Google Plugin for Eclipse team at Google has dropped support for GWT Designer. However, GXT fully supports UIBinder, which makes it easy to create UI layouts using XML, including simple HTML.

What debugging tools can I use with GXT?

GXT works with GWT super dev mode, which lets you view and set breakpoints in your Java code in the browser through the magic of source maps. SDM works well with the developer tools in Chrome, Firefox, Safari, and IE11+. Watch these demos showing super dev mode in Eclipse and IntelliJ:

GWT also works with GWT classic dev mode using browser plugins.

Can I debug GXT in a mobile web application?

Yes! One of the benefits of GWT super dev mode is that it can also be used with mobile browsers including Chrome remote debugging for Android and the Safari Web inspector for iOS. On Android using Chrome remote debugging, you can even debug GWT code running in a native app that utilizes a WebView.

Data access

How does a GXT app communicate with the server?

GXT provides generic interfaces to populate widgets with data. It is protocol-agnostic, so you can use GXT with any back-end. GXT provides adapters that support all [GWT communication methods] (, including

  • GWT-RPC (used with gwt-servlet, provides automatic JSON serialization)
  • RequestFactory (entity-centric, also provides JSON serialization)
  • RequestBuilder (raw HTTP with JSON / XML)

Does GXT support REST APIs?

GXT is protocol-agnostic so you can use it with any back-end, including a REST API. It's very easy to use GXT with the open source library RestyGWT. For an example, see David Chandler's talk from GWT.create 2015:

Application architecture (MVP, etc.)

Does GXT enforce a particular application architecture?

No. GXT provides primarily widgets and communication interfaces, not an opinionated application framework. You can use GXT with many popular GWT frameworks such as gwt-platform.

Can I use GXT with GWT Activities and Places?

Certainly. The [Executive Dashboard] ( GXT sample app uses [GWT Activities and Places] ( for browser history management.

Can I use both GXT widgets and GWT widgets in my application?

Yes. GXT widgets extend the GWT Widget class and GXT's cell-based widgets are all interchangeable with GWT's cell widgets. However, GXT layout containers use programmatic layout where resize events bubble down the view hierarchy. Since GWT widgets do not participate in the GXT layout system, it is recommended not to interleave GWT widgets and GXT widgets. We usually recommend that you have all GXT widgets down to the leaf nodes which are GWT widgets or vice versa.

Is GXT cross-compatible with Sencha ExtJS?

Not directly, although there are many similar widgets and concepts in the two frameworks. GWT 2.8 will introduce JSInterop, which will enable more interoperability between GWT and Javascript frameworks in general.

Is GXT compatible with Vaadin framework?

No. Vaadin is a full-stack framework consisting of the Vaadin server and GWT widgets for the client; you can only use Vaadin widgets with the Vaadin server and proprietary communication protocol. In contrast, GXT is used to build rich web clients with any back-end or protocol. Historically, GXT's focus has been the front-end, not the server. GXT excels at providing a rich widget library that works even with older browser versions and also tablets as of GXT 4.

Customization and theming

How do I customize the appearance of my GXT app?

Out of the box, GXT provides four themes which you can see in the GXT Explorer example below. In addition, you can create your own custom theme using a theme config file. To see what's possible with a custom theme, see the Executive Dashboard sample app below.

In addition, more advanced customization is possible in Java code using the Appearance pattern supported by all GXT widgets.

Can I also customize widget behavior?

Yes. You can extend many GXT widget classes and override their methods to provide custom behavior. Of course, you can also create new widgets using the GXT base classes.

Example applications

Where can I see all the GXT widgets with example code?

Where can I find an end-to-end sample app using GXT?


Sencha GXT is commercial software licensed per developer seat. For older versions, there is a GPL license available for open source projects. The latest commercial version is 3.1.4 and the latest GPL version is 3.1.1. Customers who have purchased support also have access to

For specific licensing questions, please contact Sales.


Can I purchase support for GXT?

Sencha offers multiple levels of support. As a support customer, you will have access to our premium forums to get help from support engineers, report bugs, and, depending on your level, access nightly builds in order to get bug fixes quickly. Please contact Sales for a quote.


Who uses GXT?

Sencha GXT customers include many of the Fortune 500. Many have found that GXT is an ideal way to port client-side Java code such as Swing applications from the desktop to the web. Many customers are using GXT to build enterprise applications with sophisticated architectures such as metadata-driven user interfaces. GXT is ideal for very large web apps which require the manageability of Java.

You can find testimonials from GXT customers on the GXT product page.

What is Sencha's relationship with GWT?

In 2012, Google fully open-sourced GWT and created the GWT Steering Committee, on which Sencha has a seat. GXT engineers contribute to GWT open source projects such as the GWT Plugin for Eclipse. The GXT team actively monitors the GWT builds and generally tries to ensure that GXT works with new versions of GWT as soon as they are released.

GXT 3.x