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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


Using GXT 2.x and 3.x Together

To allow a smooth transition from GXT 2 to 3, GXT lets you include both v2 and v3 components in the same application. This article explains the steps you need to take to run components from both versions at the same time.

  • Note: We have released GXT 2.3.1a which is compatible with GWT 2.6, and so with GXT 3.1.


  • Check out the SDK versions for compatibility options.

Changes highlights

Overall changes that will be encountered when upgrading to 3.x+

  • setLayout in 2.x becomes in 3.x specific containers
  • Model data based on properties moves to plain old to Java objects that are serializable.
    • Auto beans can be used to create these objects from JSON.
    • The bean model in 2.x but backed by properties and not in 3.x, unless the plain old java object implements a property format.
  • External CSS to changes CssResources which are much more performant.
  • Events listeners change to event handlers
  • gxtWidget.el() becomes gxtWidget.getElement();

Overall considerations

Most common things to Keep in mind when using 2 GXT 2.x and 3.x libraries.

  • Use a id prefix for one of the sdk versions, such as in 2.x GXT.setAutoIdPrefix("o"). This helps both versions layout engines work together.
  • When using 3.x programmatic sizing containers that implement top level down sizing and the child widgets are 2.x, they have to be passed a size manually.
    • Add resize handlers to the parent container and using that sizing event to size the child could be used to size them too.
  • It's recommened to use 3.x+ containers with 2.x children although keep in mind how top level sizing works too.
  • Don’t mix loaders and proxies, use one or the other SDK versions.
  • Switch to 3.x grids when you can.

Project setup

First, you'll need to set up your project to build against both GXT 2 and 3.

1. Add libraries

GXT 2 requires you to add the the appropriate JAR to your project's classpath. In the same way, add the GXT 3 JAR.

2. Add static resources

GXT 2 further requires that you copy the resources to your project war directory. In GXT 3, all resources are included in the library JAR, so no additional resources directory is necessary.

3. Inherit modules

Finally, GXT 2 has a module you must inherit in your own project's module configuration. Add the GXT 3 module in the same way.

<module rename-to='mixed'>
  <inherits name='com.extjs.gxt.ui.GXT' />
  <inherits name='com.sencha.gxt.ui.GXT' />

  <entry-point class='com.sencha.mixed.client.SimpleExample' />


Simple example

Any components that do not need to be sized by their container can be simply used as-is. In this example, a v2 and v3 button are both used.

  public void onModuleLoad() {
    HorizontalPanel bar = new HorizontalPanel();

    Button button = new Button("2.0 Button");
    button.addSelectionListener(new SelectionListener<ButtonEvent>() {
      public void componentSelected(ButtonEvent ce) {
        Info.display("Action", "The " + ce.getButton().getText() + " button clicked");

    TextButton button2 = new TextButton("3.0 Button");
    button2.addSelectHandler(new SelectHandler() {
      public void onSelect(SelectEvent event) {
        TextButton b = (TextButton)event.getSource();
        Info.display("Action", "The " + b.getText() + " button clicked");



Same name example

In the previous example, the component names are different (Button & TextButton). You can also use components with the same name. This is possible because the package namespaces are different between v2 and v3.

  public void onModuleLoad() {
    HorizontalPanel bar = new HorizontalPanel();

    ContentPanel panel = new ContentPanel();
    panel.setHeading("2.0 Panel");
    panel.setSize(200, 100);

    com.sencha.gxt.widget.core.client.ContentPanel panel2 = new com.sencha.gxt.widget.core.client.ContentPanel();
    panel2.setHeadingText("3.0 Panel");
    panel2.setPixelSize(200, 100);



Container examples

For components that do not need to be sized by their container's layout, you can simply add the v3 component to the v2 container or v2 component to the v3 container.

  public void onModuleLoad() {
    LayoutContainer con = new LayoutContainer(); // 2.0 container
    con.setLayout(new CenterLayout());
    con.setSize(300, 300);

    TextButton button = new TextButton("3.0 Button");

    CenterLayoutContainer con2 = new CenterLayoutContainer(); // 3.0 container
    con2.setPixelSize(300, 300);

    con2.add(new Button("2.0 Button"));


In cases where a v3 component needs to be sized by a v2 layout, you can wrap the v3 component in a v2 WidgetComponent. We have made changes to WidgetComponent that have not yet been released. They will be included in GXT 2.3, the next release in our v2 series. As a workaround, you can use the ComponentWrapper class included in the test project.

In cases where a v2 component needs to be sized by a v3 container, you can wrap the v2 component in a v3 WidgetComponent. As with the v2 WidgetComponent, the changes for the v3 WidgetComponent are not in the DP5 release. As a workaround, you can use the ThreeComponentWrapper class included in the test project.

This example shows both using v3 components in a v2 container and using v2 components in a v3 container. In both cases, a TabPanel is added to a Window. TabPanel needs to be resized when the window is resized.

  public void onModuleLoad() {
    final Window window = new Window();
    window.setHeading("2.0 Window - Resize Me");
    window.setSize(300, 200);
    window.setLayout(new FitLayout());

    com.sencha.gxt.widget.core.client.TabPanel tabs = new com.sencha.gxt.widget.core.client.TabPanel();
    tabs.add(new HTML(""), new TabItemConfig("3.0 Tab 1"));
    tabs.add(new HTML(""), new TabItemConfig("3.0 Tab 2"));
    window.add(new ComponentWrapper(tabs));

    final com.sencha.gxt.widget.core.client.Window window2 = new com.sencha.gxt.widget.core.client.Window();
    window2.setHeadingText("3.0 Window - Resize Me");
    window2.setPixelSize(300, 200);

    TabPanel tabs2 = new TabPanel();
    tabs2.add(new TabItem("2.0 Tab 1"));
    tabs2.add(new TabItem("2.0 Tab 2"));
    window2.setWidget(new ThreeComponentWrapper(tabs2));

    ButtonBar bar = new ButtonBar();
    bar.add(new Button("2.0 Window", new SelectionListener<ButtonEvent>() {

      public void componentSelected(ButtonEvent ce) {;

    bar.add(new Button("3.0 Window", new SelectionListener<ButtonEvent>() {

      public void componentSelected(ButtonEvent ce) {;


Charting example

Take a look at the ComplexContainerExample class in the test project to see the code that uses an GXT 3 Chart in an GXT 2 Window. To use charts, you need to add the GXT 3 chart JAR to the classpath and inherit the chart module.


As a migration strategy, both GXT 2 and 3 can be used at the same time. This allows an application to be upgraded to v3 over time, rather than all at once. Keep in mind that running both versions is not optimal as it increases the size of code and resources the application needs and uses.

Download the test project to see and run these examples. Then, visit the new GXT 3 forums and join the discussion there.

GXT 3.x