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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 6.2.0 - Modern Toolkit

Guide applies to: modern

Getting Organized

Ext JS encourages users to utilize a structured application architecture. In our example, we're using an MVC (Model/View/Controller) approach. This helps us keep our application's data, logic, and views described within separate silos.

Ext.define('Employees', {
    extend: '',
    alias: 'store.employees',

    data: [{
        "firstName": "Jean",
        "lastName": "Grey",
        "officeLocation": "Lawrence, KS",
        "phoneNumber": "(372) 792-6728"
    }, {
        "firstName": "Phillip",
        "lastName": "Fry",
        "officeLocation": "Lawrence, KS",
        "phoneNumber": "(318) 224-8644"
    }, {
        "firstName": "Peter",
        "lastName": "Quill",
        "officeLocation": "Redwood City, CA",
        "phoneNumber": "(718) 480-8560"

Ext.define('PopupForm', {
    extend: 'Ext.form.Panel',
    xtype: 'popupform',
    controller: 'popupform',

    title: 'Update Record',

    width: 300,
    floating: true,
    centered: true,
    modal: true,

    items: [{
        xtype: 'textfield',
        name: 'firstname',
        label: 'First Name',
        bind: '{employee.firstName}'

    }, {
        xtype: 'toolbar',
        docked: 'bottom',
        items: ['->', {
            xtype: 'button',
            text: 'Submit',
            iconCls: 'x-fa fa-check',
            handler: 'submitUpdate'
        }, {
            xtype: 'button',
            text: 'Cancel',
            iconCls: 'x-fa fa-close',
            handler: 'cancelUpdate'

Ext.define('PopupFormController', {
    extend: '',
    alias: 'controller.popupform',

    cancelUpdate: function () {
        var view = this.getView();


    submitUpdate: function(me) {
        var view = this.getView();


Ext.define('MyListViewController', {
    extend: '',
    alias: 'controller.listview',

    onPopupForm: function (view, index, item, record) {
            xtype: 'popupform',
            width: 400,
            record: record,
            viewModel : {
                data: {
                    employee: record

    name: 'Fiddle',

    launch: function() {

            xtype: 'tabpanel',
            controller: 'listview',

            items: [{
                title: 'Employee Directory',
                xtype: 'grid',
                iconCls: 'x-fa fa-users',
                listeners: {
                    itemtap: 'onPopupForm'
                store: {
                    type: 'employees'
                columns: [{
                    text: 'First Name',
                    dataIndex: 'firstName',
                    flex: 1
                }, {
                    text: 'Last Name',
                    dataIndex: 'lastName',
                    flex: 1
                }, {
                    text: 'Phone Number',
                    dataIndex: 'phoneNumber',
                    flex: 1
            }, {
                title: 'About Sencha',
                iconCls: 'x-fa fa-info-circle'


View the Example


In an MVC architecture, most classes are either Models, Views, or Controllers. The user interacts with Views, which may display data held in Models. Those interactions are monitored by a Controller, which then responds to the interactions by updating the View and Model, as necessary.

The goal of MVC is to clearly define the responsibilities for each class in the application. Because every class has clearly defined responsibilities, they become decoupled from the larger environment. This makes the app easier to test and maintain, and its code more reusable.

Classes and Inheritance

We have switched from simply creating components to defining new classes of components using the Ext.define method. These classes inherit the bulk of their functionality by virtue of their "extend" property which specifies their desired base class. The class we choose to extend is the same as we had previously been creating.

As you can see, we're using extend in our class definitions. This is a method of creating your own class that inherits all of the methods, properties, and config options from the class you're extending.

All Ext JS components inherit attributes from the Component class. That means that Component has certain abilities that are passed down to all visual components in the Ext JS framework.

As an example, TabPanel gets to use all of the abilities from Component, Container, and itself because TabPanel extends Container, and Container extends Component. This is called the inheritance chain. It's not something that you have to fully understand, but it's important to recognize its existence since it gives your visual components all of the superpowers that exist in its hierarchy.

What's Next

In the next section, we'll add more functionality and real-world data, so that our application is ready for realistic use cases.

Deep Dive

For more information about application architecture, check out our Application Architecture Overview.

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Ext JS 6.2.0 - Modern Toolkit