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.

Ext JS 6.0.1 - Modern Toolkit





A helper class for the native JavaScript Error object that adds a few useful capabilities for handling errors in an application. When you use Ext.Error to raise an error from within any class that uses the Class System, the Error class can automatically add the source class and method from which the error was raised. It also includes logic to automatically log the error to the console, if available, with additional metadata about the error. In all cases, the error will always be thrown at the end so that execution will halt.

Ext.Error also offers a global error handling method that can be overridden in order to handle application-wide errors in a single spot. You can optionally ignore errors altogether, although in a real application it's usually a better idea to override the handling function and perform logging or some other method of reporting the errors in a way that is meaningful to the application.

At its simplest you can simply raise an error as a simple string from within any code:

Example usage:

Ext.raise('Something bad happened!');

If raised from plain JavaScript code, the error will be logged to the console (if available) and the message displayed. In most cases however you'll be raising errors from within a class, and it may often be useful to add additional metadata about the error being raised. The raise method can also take a config object. In this form the msg attribute becomes the error description, and any other data added to the config gets added to the error object and, if the console is available, logged to the console for inspection.

Example usage:

Ext.define('Ext.Foo', {
    doSomething: function(option){
        if (someCondition === false) {
                msg: 'You cannot do that!',
                option: option,   // whatever was passed into the method
                'error code': 100 // other arbitrary info

If a console is available (that supports the console.dir function) you'll see console output like:

An error was raised with the following data:
option:         Object { foo: "bar"}
    foo:        "bar"
error code:     100
msg:            "You cannot do that!"
sourceClass:   "Ext.Foo"
sourceMethod:  "doSomething"

uncaught exception: You cannot do that!

As you can see, the error will report exactly where it was raised and will include as much information as the raising code can usefully provide.

If you want to handle all application errors globally you can simply override the static handle method and provide whatever handling logic you need. If the method returns true then the error is considered handled and will not be thrown to the browser. If anything but true is returned then the error will be thrown normally.

Example usage:

Ext.Error.handle = function(err) {
    if (err.someProperty == 'NotReallyAnError') {
        // maybe log something to the application here if applicable
        return true;
    // any non-true return value (including none) will cause the error to be thrown
No members found using the current filters


Static Properties

ignore : Boolean
static sta

Static flag that can be used to globally disable error reporting to the browser if set to true (defaults to false). Note that if you ignore Ext errors it's likely that some other code may fail and throw a native JavaScript error thereafter, so use with caution. In most cases it will probably be preferable to supply a custom error handling function instead.

Example usage:

Ext.Error.ignore = true;

Defaults to:



Static Methods

handle ( err )
static sta

Globally handle any Ext errors that may be raised, optionally providing custom logic to handle different errors individually. Return true from the function to bypass throwing the error to the browser, otherwise the error will be thrown and execution will halt.

Example usage:

Ext.Error.handle = function(err) {
    if (err.someProperty == 'NotReallyAnError') {
        // maybe log something to the application here if applicable
        return true;
    // any non-true return value (including none) will cause the error to be thrown


err :  Object

The error being raised. It will contain any attributes that were originally raised with it, plus properties about the method and class from which the error originated (if raised from a class that uses the Class System).

raise ( err )
deprecated dep static sta

This method is called internally by Ext#raise. Application code should call Ext#raise instead of calling this method directly.


err :  Object

Deprecated since version 6.0.0
Use Ext#raise instead.

Ext JS 6.0.1 - Modern Toolkit