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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.

Sencha Inspector


Inspecting Desktop Apps

There are three basic ways to connect your app with Sencha Inspector:

  • Use a browser "bookmarklet", which does not add any code to your application
  • Use Sencha Cmd to run sencha app watch with an additional special flag
  • Add a few lines of code to your application's app.json and Application.js files

Which method is better for you depends on several factors:

  • You do (or do not) want to change any code in your application
  • The app is (or is not) being hosted locally by Sencha Cmd
  • You are aiming to inspect a deployed app that may be remote
  • You are aiming to inspect an app on your local machine that you are currently developing

Each of the methods has their pros and cons, but they are all relatively easy to employ.

Configuring Dev Builds

You should use this method if you are planning to use Sencha Inspector during the development phase and especially if you are using Sencha Cmd. If you are using Sencha Cmd, this will also allow you to inspect app theming (Ext JS 6+), which offers a powerful method of dynamic theming.

To configure a development application, you have two options:

  • Use Sencha Cmd to run sencha app watch with an additional special flag
  • Add a few lines of code to your application's app.json and Application.js files

Using Sencha Cmd to Connect Directly

Without adding any code to your application, you can run sencha app watch --inspect to start the Sencha Cmd web server. The additional --inspect flag will automatically inject some code connecting your application to Sencha Inspector.

Note: Be sure that Sencha Inspector is already running on your machine at port 1839 before running that command.

Your application will now be viewable in a browser at http://localhost:1841 and Sencha Inspector should automatically detect it and allow you to inspect the application.

Configuring Apps for Connection

Alternatively you can add a few lines of code that will connect your application to Sencha Inspector.

First, open app.json and locate the "js" array. Next, edit it to include following lines:

 "js" : [

      ..//existing scripts

           // default settings
           "path" : "",

           // Or Use your Machine Name
           //"path" : "http://MyComputerName:1839/inspector.js",

           // Or Use your IP Address
           //"path" : "http://123.456.78.90:1839/inspector.js",

           "remote"    : true,
           "bootstrap" : true


After adding this configuration to app.json, you also need to add initialization code to your app. Locate {appRoot}/app/Application.js and then modify it to include the launch() method as in example below.

 //Do not modify entire Application.js - "DemoClient" is just an example name  

 Ext.define('DemoClient.Application', {  
      extend: '',       
      name: 'DemoClient',  

      stores: [  

      //Add Sencha Inspector init to launch function  
      launch: function () {
          // <debug>
          try {
               * init() defaults to ""
               * so we don't have to pass a URL

               * NOTE: The URL needs to match what you defined in app.json.
               * If you connected app.json via a machine name or IP address,
               * you'll need to explicitly configure that here too
              // SenchaInspector.init('http://MyComputerName:1839');
          } catch (e) {}
          // </debug>

Notice that we're wrapping the call to init() inside debug flags. Sencha Cmd will ignore all code between those blocks during a production build.

Finally, use Sencha Cmd to run sencha app watch. This will allow you to preview your application in browser at http://localhost:1841. If the configuration is correct, Sencha Inspector should automatically detect it and allow you to inspect the application.

Connecting Ext JS 4.2.x applications

Sencha Inspector also works with Ext JS 4.2.x applications. However, you will need to take slightly different steps than above.

For Ext JS 4.2.x applications, you'll want to add the following code to your Application.js file:

launch: function() { 

Then, in index.html, add the following include to the <x-compile> blocks:

<script type="text/javascript" src=""></script>

Inspect Deployed App

This method relies on using a "bookmarklet" to setup a connection between the app and Sencha Inspector. You should use this method if you are connecting with an Ext JS or Touch app that is:

  • Already deployed
  • Not running on a local machine
  • Not built using Sencha Command

There are some drawbacks to using this method. For instance, you cannot use Sencha Inspector to inspect an application's theme if connecting via bookmarklet.

Connecting Apps via Bookmarklet

What is a "bookmarklet"?

A "bookmarklet" is a tiny bit of JavaScript code saved as a bookmark inside the browser. You use a bookmarklet by clicking it inside a browser, as you would a regular bookmark. The JavaScript code will then execute on the page in which it was loaded.

Configuring the Bookmarklet

Sencha Inspector provides a way to configure the bookmarklet for the app you want to inspect.

  1. Click the "Connect your app..." button in the top toolbar of the main Sencha Inspector window.

  2. Click the "Create Bookmarklet" button in the window overlay

  3. Drag the button on the screen to the bookmarks bar in your browser; this will create a new bookmark with the appropriate bookmarklet code for Sencha Inspector. (Note: you can change the settings of the bookmarklet by clicking "Advanced Settings")

  4. Open the app that you want to inspect in the browser

  5. Click the bookmarklet that you created.

If you followed all the steps above, Sencha Inspector should detect your app and allow you to inspect it.

Learning Path

Sencha Inspector