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.

Cmd 7.5.1


Generating Metadata

The metadata tracked by the Sencha Cmd compiler has a variety of uses, some of which we will examine in this guide. To support these uses, the compiler can export and format this metadata in several different ways, which we will cover here as well.


The following guides are recommended reading before proceeding further:

Generating Output with meta

One of the major new dimensions provided by the compiler is its ability to export metadata in various formats. This feature is used to produce the ext.js "bootstrap" file that contains various classes and a block of metadata about all of the files in the framework.

There are several forms of metadata that the compiler can export using the meta command:

  • Class aliases
  • Alternate class names
  • Loader paths
  • Filenames
  • Definitions

Generating a Custom Bootstrap

Note. This process is handled automatically for applications generated by Sencha Cmd. If you are not using Sencha Cmd generated application, this section describes how to achieve the same results manually.

The primary use for the meta command is to create your own "bootstrap" file. This file gives the framework the same level of awareness of your application code that it has of the framework code itself.

The simplest way to manage your bootstrap file is to store it alongside your markup file. If that won't work for you, read on to see how to manage relative paths. If you have your markup file in a source folder in your classpath, you need to tell the compiler to ignore the bootstrap file. Do this using the -ignore switch:

sencha compile -classpath=sdk/src,app -ignore bootstrap.js \

Enabling Wildcard Support in requires

The end of "ext-debug.js" contains these two function calls:

    "Ext.draw.engine.ImageExporter": [],
    "Ext.layout.component.Auto": [],

    "Ext.draw.engine.ImageExporter": [],
    "Ext.layout.component.Auto": [

It is the presence of these two pieces of metadata that allow wildcards to be used in requires statements. That is:

Ext.define('MyApp.App', {
    requires: [

All that is required to use wildcards in your own code is to provide the same bootstrap data for your app.

This command will produce a file that does just that:

sencha compile -classpath=app \
    meta -alias -out bootstrap.js and \
    meta -alt -append -out bootstrap.js

The above command line tells the compiler to read in the source in the app folder and generate two pieces of metadata. The second piece of metadata is written to the same output file as the first, but using the -append option to append to the file and not replace it.

Once you have the "bootstrap.js" file, change your page like so to add it to the x-bootstrap section:

        <!-- <x-compile> -->
            <!-- <x-bootstrap> -->
                <script src="../sdk/ext-dev.js" type="text/javascript"></script>

                <script src="bootstrap.js" type="text/javascript"></script>
            <!-- </x-bootstrap> -->

            <script src="app/app.js" type="text/javascript"></script>
        <!-- </x-compile> -->

The "bootstrap.js" file needs to be regenerated if you do any of the following:

  • Add a class
  • Remove a class
  • Change class aliases
  • Change class alternate names

This rebuild of the bootstrap data can be handled in a variety of ways, but the fundamental question is whether to keep these files in source control or require developers to generate them locally. Both approaches work and can be automated to some degree.

Note. For applications generated by Sencha Cmd, this is handled as part of the build process of sencha app build. Alternatively, refreshing just the bootstrap instead of performing a full build is accomplished by the sencha app refresh command.

Exporting Loader Paths

In large applications it can be helpful to organize your namespace using multiple source trees. In fact, Ext JS itself uses three source trees. This approach, however, has always presented problems for the dynamic loader requiring loader paths to be configured by hand to work around the issue. The compiler, however, has complete knowledge of class-to-file relationships given all of the source in the classpath. And the meta command can export that data for use in your application.

If you are already sold on the above to create a "bootstrap.js", this data can be added by adding one more meta command (of course, the classpath will contain multiple folders in this case):

sencha compile -classpath=src1,src2,src3 \
    meta -alias -out bootstrap.js and \
    meta -alt -append -out bootstrap.js and \
    meta -loader -append -out bootstrap.js

Now the "bootstrap.js" file solves both problems. With this approach, the following things will also require you to rebuild "bootstrap.js":

  • Rename a file or folder
  • Reorganize the classpath
  • Reorganize the content of any of the source trees

Note. This part is also handled automatically for applications generated by Sencha Cmd.

Resolving Relative Paths with -base-path

For many good reasons, paths need to be relative. Whenever you deal with relative paths, however, you need to solve the problem of where those relative paths are based. In the above examples we cheated a bit and placed the "bootstrap.js" file next to the markup file. This leverages the fact that the meta command defaults the base folder to the location of the output file.

When this is not the case, you need to tell the meta command the base for determining relative paths. Let's say we want to move the "bootstrap.js" file in to the "build" folder (perhaps because we are not keeping it in source control). Since our page is in the current folder and our source is in the "app" folder, this will generate the proper relative paths:

sencha compile -classpath=src1,src2,src3 \
    meta -alias -out build/bootstrap.js and \
    meta -alt -append -out build/bootstrap.js and \
    meta -loader -append -base-path . -out build/bootstrap.js

Since the -alias and -alt modes do not deal in paths, the -base-path option is only needed on the -loader use of the meta command.

Changing the Format

By default, the meta command exports metadata in JSONP format using a function call wrapper appropriate for the type of metadata requested. If a different function call is desired or you want the data in JSON format, you can request this in the meta command.

In the example below, the aliases.json file will contain the alias data in JSON format. You cannot use -append in this case because JSON format requires a single, top-level object or array.

sencha compile -classpath=src1,src2,src3 \
    meta -alias -json -out aliases.json

In this next example, we customize the JSONP wrapping by supplying the function to call:

sencha compile -classpath=src1,src2,src3 \
    meta -alias -jsonp -out aliases.js

This form can work with -append because it produces JavaScript code. The output of the above looks roughly like this:
    // ... the JSON data ...

Exporting Filenames

An occasionally useful form of metadata supported by the meta command is filename data. That is, the list of a files in the proper, dependency order. In many ways this is the same as the other meta data forms in that this data can be exported in JSON or JSONP format, and can be combined using -append.

The first difference with -filenames is that the default format is text. To produce JSON or JSONP, you must specify one of the -json or -jsonp options.

In the default mode of text, the filenames are written as lines of text, one filename per line. The following command will create "filenames.txt":

sencha compile -classpath=src1,src2,src3 \
    meta -filenames -out filenames.txt

Each line of the file can be decorated using the -tpl option. Because of the special characters needed for this example, we use a response file to hold the template. We put this in "template.txt", like this:

<script src="{0}" type="text/javascript"></script>

Then run the following command.

sencha compile -classpath=src1,src2,src3 \
    meta -filenames -tpl @template.txt -out filenames.txt

We now have a chunk of markup that will "script-tag in" all of the files in their correct order.

For example:

<script src="ext/src/ShadowPool.js" type="text/javascript"></script>
<script src="ext/src/Shadow.js" type="text/javascript"></script>

Exporting Definitions

The compiler normally reads metadata such as classes, namespaces and dependencies by parsing source code. In situations where this is hidden, for example, when obfuscating a library, the compiler will be unaware of any defined classes or their dependencies.

This form of metadata export can be used to provide the "symbols" for such libraries so that users can still compile their application using Sencha Cmd.

sencha compile -classpath=src1,src2,src3 \
    meta -definitions -out symbols.js

The above creates a file that contains directives like this:

// @define
// @require Ext.panel.Panel
// @uses Ext.layout.container.HBox

These directives are recognized by the compiler and introduce the symbolic names needed for user code to compile. These symbols should be added to the obfuscated library file to ensure that the library code is concatenated in the right order.

Cmd 7.5.1