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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.

Ext JS 7.6.0


Layouts and Containers

The layout system is one of the most powerful parts of Ext JS. It handles the sizing and positioning of every Component in your application. This guide covers the basics of how to get started with layouts.


An Ext JS application UI is made up of Components (See the Components Guide for more on Components. A Container is a special type of Component that can contain other Components. A typical Ext JS application is made up of several layers of nested Components

The most commonly used Container is Panel. Let's take a look at how being a Container allows a Panel to contain other Components:

We just created a Panel that renders itself to the document body, and we used the items config to add two child Panels to our Container Panel.


Every container has a layout that manages the sizing and positioning of its child Components. In this section we're going to discuss how to configure a Container to use a specific type of Layout, and how the layout system keeps everything in sync.

Using Layouts

In the above example we did not specify a layout for the Container Panel. Notice how the child Panels are laid out one after the other, just as normal block elements would be in the DOM. This happens because the default layout for all Containers is Auto Layout. Auto Layout does not specify any special positioning or sizing rules for child elements. Let's assume, for example, we want our two child Panels to be positioned side by side, and to each take up exactly 50% of the width of the Container - we can use a Column Layout simply by providing a layout config on the Container:

Ext JS comes with a full set of layouts and can accomodate almost any type of layout you can imagine. See the Layout Section of the Kitchen Sink to see different layouts in action.

How the layout system works

A Container's Layout is responsible for the initial positioning and sizing of all of the Container's children. Internally the framework calls the Container's updateLayout method which triggers the Layout to calculate the correct sizes and positions for all of the Container's children and update the DOM. The updateLayout method is fully recursive, so any of the Container's children will have their updateLayout method called as well. This continues until the bottom of the Component hierarchy is reached. You typically will not have to ever call updateLayout() in your application code since the framework should handle it for you.

A re-layout is triggered when the Container is resized, or when child Component items are added or removed. Normally we can just rely on the framework to handle updating the layout for us, but sometimes we want to prevent the framework from automatically laying out so we can batch multiple operations together and then manually trigger a layout when we're done. To do this we use the suspendLayout flag on the Container to prevent it from laying out while we perform our operations that would normally trigger a layout (adding or removing items for example). When we're done all we have to do is turn the suspendLayout flag off and manually trigger a layout by calling the Container's updateLayout method:

Component Layout

Just like a Container's Layout defines how a Container sizes and positions its Component items, a Component also has a Layout which defines how it sizes and positions its internal child items. Component layouts are configured using the componentLayout config option.

Generally, you will not need to use this configuration unless you are writing a custom Component since all of the provided Components come with their own layout managers. Most Components use Auto Layout, but more complex Components will require a custom component layout (for example a Panel that has a header, footer, and toolbars.

Ext JS 7.6.0