ExtReact Docs Help


The documentation for the ExtReact product diverges somewhat from the documentation of other Sencha products. The sections below describe documentation for all products except where indicated as unique to ExtReact.

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.

ExtReact component classes list the configurable name prominently at the top of the API class doc followed by the fully-qualified class name.

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

Or in the case of an ExtReact component class this indicates a member of type prop

- 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.

ExtReact component classes do not hoist the getter / setter methods into the prop. All methods will be described in the Methods section

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.

ExtAngular 6.7.0


NPM Package





This class provides a common API to LocalStorage with backwards compatibility for IE.

The primary aspects of this API match the HTML5 standard API except that this class provides a scoping mechanism to isolate property values by instance. This scope is determined from the id property. Further, this class does not expose the number of keys in the store as a length property as this cannot be maintained reliably without undue cost. Instead there is a getKeys method that returns the cached array of keys which is lazily populated on first call.

For example:

 var store = new Ext.util.LocalStorage({
         id: 'foo'

 store.setItem('bar', 'stuff');

 // Equivalent to:
 window.localStorage.setItem('foo-bar', 'stuff');

In all cases, the id property is only used by the underlying storage and should not be needed in item access calls or appear when enumerating keys.

To continue with the previous example:

 var keys = store.getKeys();
 console.log(keys.length);   // logs 1
 console.log(store.key(0));  // logs "bar"

Sharing Instances

The management of the underlying storage can be broken if multiple instances of this class are created with the same id simultaneously. To avoid creating multiple instances with the same id, use the get method and it will lazily create and share a single instance. When you are done with the shared instance, call release.

 var storage = Ext.util.LocalStorage.get('id');


 storage.release(); // do not call destroy as others may be using this object

IMPORTANT: Do not mix direction instantiation and get with the same id.

Legacy IE

Older IE browsers (specifically IE7 and below) do not support localStorage so this class provides equivalent support using the IE proprietary persistence mechanism: the userData behavior.aspx). In this mode, the id serves as name passed to the load and save methods and as the suffix on the DOM element added to the head.

In this mode, writes to the underlying storage are buffered and delayed for performance reasons. This can be managed using the flushDelay config or by directly calling the save method.

No members found using the current filters


Optional Configs

flushDelay : Number

The number of milliseconds to delay writing changes to the underlying store. This applies only to legacy IE mode and helps batch multiple writes into one flush to storage.

Defaults to:


id : String

The unique identifier for this store. This config is required to scope this storage distinctly from others. Ultimately, this is used to set a prefix on all keys.

lazyKeys : Boolean

Determines if the keys collection is continuously maintained by this object. By default the keys array is lazily fetched from the underlying store and when keys are removed, the array is discarded. This heuristic tends to be safer than doing the linear removal and array rippling to remove keys from the array on each call to removeItem. If the cost of scanning localStorage for keys is high enough and if the keys are frequently needed, then this flag can be set to false to instruct this class to maintain the keys array once it has been determined.

Defaults to:


prefix : String

The prefix to apply to all localStorage keys manages by this instance. This does not apply to the legacy IE mechanism but only to the HTML5 localStorage keys. If not provided, the id property initializes this value with "id-".

Defaults to:


session : Boolean

Specify this as true to use sessionStorage instead of the default localStoreage. This option is not supported in legacy IE browsers (IE 6 and 7) and is ignored.

Defaults to:




Instance Methods


Removes all of the keys of this storage. NOTE: This method conforms to the standard HTML5 Storage interface.


Destroys this instance and for legacy IE, ensures data is flushed to persistent storage. This method should not be called directly on instances returned by the get method. Call release instead for such instances.

NOTE: For non-legacy IE browsers, there is no harm in failing to call this method. In legacy IE, however, failing to call this method can result in memory leaks.

get ( id ) : Ext.util.LocalStorage

Returns a shared instance of the desired local store given its id. When you are finished with the returned object call the release method:

 var store = Ext.util.LocalStorage.get('foo');

 // .. use store


NOTE: Do not mix this call with direct instantiation of the same id.


id :  String/Object

The id of the desired instance or a config object with an id property at a minimum.



The desired instance, created if needed.

getItem ( key ) : String

Returns the value associated with the given key. NOTE: This method conforms to the standard HTML5 Storage interface.


key :  String

The key.



The value associated with the given key.

getKeys String[]

Returns the keys for this storage.



The keys for this storage. This array should be considered as readonly.

key ( index ) : String

Returns the specified key given its index. These keys have the scoping prefix removed so they match what was passed to setItem. NOTE: This method conforms to the standard HTML5 Storage interface.


index :  Number

The index of the desired key.



The key.


Call this method when finished with an instance returned by get instead of calling destroy. When the last shared use of this instance calls release, the destroy method is called automatically.

NOTE: Failing to call this method will result in memory leaks.

removeItem ( key )

Removes the value associated with the given key. NOTE: This method conforms to the standard HTML5 Storage interface.


key :  String

The key.

save ( [delay] )

This method ensures the content of the store is saved to the underlying storage. This applies only to legacy IE. This is not normally called by user code but can be called to ensure storage is saved.


delay :  Number (optional)

Defaults to: 0

setItem ( key, value )

Sets the value associated with the given key. NOTE: This method conforms to the standard HTML5 Storage interface.


key :  String

The key.

value :  String

The new associated value for key.

ExtAngular 6.7.0