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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 7.1.0 - Classic Toolkit



NPM Package





Manages factories for families of classes (classes with a common alias prefix). The factory for a class family is a function stored as a static on Ext.Factory. These are created either by directly calling Ext.Factory.define or by using the Ext.mixin.Factoryable interface.

To illustrate, consider the layout system's use of aliases. The hbox layout maps to the "layout.hbox" alias that one typically provides via the layout config on a Container.

Under the covers this maps to a call like this:


Or possibly:

     type: 'hbox'

The value of the layout config is passed to the Ext.Factory.layout function. The exact signature of a factory method matches create.

To define this factory directly, one could call Ext.Factory.define like so:

 Ext.Factory.define('layout', 'auto');  // "" is the default type
No members found using the current filters


Optional Configs

aliasPrefix : String

The prefix to apply to type values to form a complete alias. This defaults to the proper value in most all cases and should not need to be specified.

Available since: 5.0.0

creator : String

The name of the method used to prepare config objects for creation. This defaults to 'create' plus the capitalized name (e.g., 'createLayout' for the 'laoyut' alias family).

Defaults to:

'create' + Ext.String.capitalize(

defaultProperty : String

The config property to set when the factory is given a config that is a string.

Defaults to:


Available since: 5.0.0

defaultType : String

An optional type to use if none is given to the factory at invocation. This is a suffix added to the aliasPrefix. For example, if aliasPrefix="layout." and defaultType="hbox" the default alias is "layout.hbox". This is an alternative to xclass so only one should be provided.

Defaults to:


Available since: 5.0.0

instanceProp : String

The property that identifies an object as instance vs a config.

Defaults to:


Available since: 5.0.0

typeProperty : String

The property from which to read the type alias suffix.

Defaults to:


Available since: 6.5.0

xclass : String

The full classname of the type of instance to create when none is provided to the factory. This is an alternative to defaultType so only one should be specified.

Defaults to:


Available since: 5.0.0


Instance Properties

defaultClass : Ext.Class
readonly ro private pri

The Class reference of the type of instance to create when none is provided to the factory. This property is set from xclass when the factory instance is created.

Defaults to:


Available since: 5.0.0


Instance Methods

create ( [config], [defaultType] ) : Object

Creates an instance of this class family given configuration options.

Available since: 5.0.0


config :  Object/String (optional)

The configuration or instance (if an Object) or just the type (if a String) describing the instance to create.

xclass :  String (optional)

The full class name of the class to create.

type :  String (optional)

The type string to add to the alias prefix for this factory.

defaultType :  String/Object (optional)

The type to create if no type is contained in the config, or an object containing a default set of configs.



The newly created instance.

dataIdentifier ( config ) : Object

Returns an instance of an ID generator based on the ID you pass in.


config :  String/Object

The config object or id to lookup.


:Object* The data identifier

hook ( fn )
private pri

Sets a hook on the creation process. If the hook fn returns undefined then the original create method is called.

Available since: 6.5.0


fn :  Function

The hook function to call when create is invoked.

original :  Function

The original create method.

config :  String / Object

See create.

defaultType :  String / Object

See create.

update ( instance, config, [creator], [creatorMethod], [defaultsConfig] ) : Object

This method accepts a config object and an existing instance if one exists (can be null).

The details are best explained by example:

 config: {
     header: {
         xtype: 'itemheader'

 applyHeader: function (header, oldHeader) {
     return Ext.Factory.widget.update(oldHeader, header,
         this, 'createHeader');

 createHeader: function (header) {
     return Ext.apply({
         xtype: 'itemheader',
         ownerCmp: this
     }, header);

Normally the applyHeader method would have to coordinate potential reuse of the oldHeader and perhaps call setConfig on it with the new header config options. If there was no oldHeader, of course, a new instance must be created instead. These details are handled by this method. If the oldHeader is not reused, it will be destroy.

For derived class flexibility, the pattern of calling out to a "creator" method that only returns the config object has become widely used in many components. This pattern is also covered in this method. The goal is to allow the derived class to callParent and yet not end up with an instantiated component (since the type may not yet be known).

This mechanism should be used in favor of Ext.factory().

Available since: 6.5.0


instance :  Ext.Base

config :  Object/String

The configuration (see create).

creator :  Object (optional)

If passed, this object must provide the creator method or the creatorMethod parameter.

creatorMethod :  String (optional)

The name of a creation wrapper method on the given creator instance that "upgrades" the raw config object into a final form for creation.

defaultsConfig :  String (optional)

The name of a config property (on the provided creator instance) that contains defaults to be used to create instances. These defaults are present in the config object passed to the creatorMethod.



The reconfigured instance or a newly created one.

Static Methods

define ( type, [config] ) : Function
static sta

For example, the layout alias family could be defined like this:

 Ext.Factory.define('layout', {
     defaultType: 'auto'

To define multiple families at once:

     layout: {
         defaultType: 'auto'

Available since: 5.0.0


type :  String

The alias family (e.g., "layout").

config :  Object/String (optional)

An object specifying the config for the Ext.Factory to be created. If a string is passed it is treated as the defaultType.



Ext JS 7.1.0 - Classic Toolkit