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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.

- Public classes and class members are available for use by any other class or application code and may be relied upon as a stable and persistent within major product versions. Public classes and members may safely be extended via a subclass.

- Protected class members are stable `public` members intended to be used by the owning class or its subclasses. Protected members may safely be extended via a subclass.

- Private classes and class members are used internally by the framework and are not intended to be used by application developers. Private classes and members may change or be omitted from the framework at any time without notice and should not be relied upon in application logic.

### Member Types

- Config - The configuration options for a class.
- Property - Set once a class is instantiated. *See Read Only below.
- Method - Actions that can be performed by a class. Methods should be read as instance methods and can only be called from a instance of a given class. Static methods that can be called directly from the class itself will have a `static` label next to the method name. *See Static below.
- Event - Events are specific to the framework event system allowing for classes to programmatically raise an event to be handled by one or more event handler methods. DOM events, while handled by the framework event system, are not specifically described within the API documentation. *For DOM events refer to the event reference page from MDN.
- Theme Variable - Variables used by the visual theme engine employed by the framework.
- Theme Mixin - Functions used by the visual theme engine employed by the framework and may use values set in various Theme Variables.

### 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).

Ext.container.Container
view source
lookupComponent ( item ) : Ext.Component
protected

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.

Parameters

item : Object

The config object being added.

Returns
Ext.Component

The component to be added.

Let's look at each part of the member row:

- Expand/Collapse - On the left-hand size of the member row is a control used to expand and collapse each member row to show / hide member details.
- Member Name - The name of the class member (`lookupComponent` in this example)
- Method Param - Any required or optional params used by a method (or passed to an event handler method) will be listed next to the method name within parenthesis (`( item )` in this example)
- Return type - The class instance or javascript object returned by the method or property (`Ext.Component` in this case). This may be omitted for methods that do not return anything other than `undefined` or may display as multiple possible values separated by a forward slash `/` signifying that what is returned may depend on the results of the method call (i.e. a method may return a Component if a get method calls is successful or `false` if unsuccessful which would be displayed as `Ext.Component/Boolean`).
- Flags - Any flags applicable to the member will be displayed next (`PROTECTED` in this example - see the Flags section below)
- Member Origin - On the right-hand side of the member row is the class where the member was initially described (`Ext.container.Container` in this example). The source class will be displayed as a blue link if the member originates from the current class and gray if it is inherited from an ancestor or mixed-in class.
- Member Source - On the right-hand side below the member origin class is a link to view the member's source (`view source` in the example)
- Params List - Each param for a class method will be listed using the same name found above in parenthesis, the type of class or object expected, and a description of the param (`item : Object` in the example).
- Returns - If a class returns a value other than `undefined` a "Returns" section will note the type of class or object returned and a description (`Ext.Component` in the example)
- Since (not shown in the example) - Some members will show which version of the product the member was first introduced (i.e. `Available since 3.4.0` - not pictured in the example) just after the member description
- Default (not shown in the example) - Configs often show the default config value to be applied to a class instance if not overridden (i.e. `Defaults to: false`)

### 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.

- Required - Required config when instantiating a class
- Bindable - The config has a setter which allows this config to be set via ViewModel binding
- Read Only - The property may be read, but cannot be used to configure / re-configure a class instance at runtime
- Singleton - Singleton classes are instantiated immediately once defined and may not be instantiated manually
- Static - A static method or property is a method or property belonging to the class itself, not an instance of the class
- Chainable - Refers to methods that return the class instance back when called.
  This enables chained method calls like: `classInstance.method1().method2().etc();`
- Deprecated - A class or member that is scheduled for removal in a future framework version and is provided in the current version for backwards compatibility.
  Deprecated classes and members will have a message directing you to the preferred class / method going forward.
- Removed - A removed class or member that exists in documentation only as a reference for users upgrading between framework versions
- Template - A method defined within a base class designed to be overridden by subclasses
- Abstract - A class or member may be be defined as abstract. Abstract classes and members establish a class structure and provide limited, if any, code. Class-specific code will be furnished via overrides in subclasses.
- Preventable - Events marked preventable will not fire if `false` is returned from an event handler

### 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

## Navigation and Features

### 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 and inheritance. This is done using the checkboxes at the top of the page. Note that filtering out `private` members also filters the API class navigation tree.

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:

- Alternate Name - One or more additional class name synonymns (in Ext JS 6.0.0 the `Ext.button.Button` class has an alternate class name of `Ext.Button`). Alternate class names are commonly maintained for backward compatibility.
- Hierarchy - The hierararchy view lists the inheritance chain of the current class up through its ancestor classes up to the root base class.
- Mixins - A list of classes that are mixed into the current class
- Inherited Mixins - A list of classes that are mixed into an ancestor of the current class
- Requires - All classes required to be defined for the class to be instantiated
- Uses - A list of classes potentially used by the class at some point in its lifecycle, but not necessarily requried for the class to initially be instantiated
- Subclasses - Classes that extend the current class

### 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:

- Global navigation will be located in a menu on the left-hand side accessible via the hamburger menu icon. The menu houses the following (on most pages):
  - The name of the current product (as a link to the product landing page)
  - The Sencha icon used to navigate back to the documentation home page
  - The product menu drop-down button
  - Tabs of navigation trees for the API docs and guides
- Current context navigation and tools is located on the right-hand side accessible via the gear icon. The context menu houses teh following:
  - The global search input field
  - (API doc) A "Filters" tab with the member filter, expand / collapse all examples button, expand / collapse all member rows button, the access level filter checkboxes, and the counts of each member
  - (API doc) A "Related Classes" tab containing the menu of metadata related to the current class
  - (Guides) The table of contents for the guide

### 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.

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# ViewControllers in Ext JS

Ext JS delivers some exciting improvements for you to use in your application architecture. We have added support for ViewModels and MVVM as well as ViewControllers to enhance MVC applications. Best of all, these choices are not mutually exclusive, so you can introduce these features incrementally or even blend them.

## Application-level Controllers

A Controller is a class derived from Ext.app.Controller. These Controllers use CSS-like selectors (called “Component Queries”) to match components and respond to their events. They also use “refs” to select and retrieve component instances.

These controllers are created at application launch and remain present for the life of the application. During its lifetime, views of interest to a controller will come and go. There may even be multiple instances of views that the controller manages.

### Challenges

For large applications, these techniques can create certain challenges.

In such environments, views and controllers may be authored by multiple development teams and integrated into the final application. Ensuring that controllers only react to their intended views can be difficult. Further, it is common for developers to want to limit the number of controllers created at application launch. While lazily creating controllers is possible with some effort, they can’t be destroyed, so they remain even if they are no longer needed.

## ViewControllers

While Ext JS 5+ is backwards compatible with legacy application-level controllers, it introduces a new type of controller designed to handle these challenges: Ext.app.ViewController. ViewController does this in the following ways:

- Simplifies the connection to views using “listeners” and “reference” configs.
- Leverages the life cycle of views to automatically manage their associated ViewController.
- Reduces complexity in the ViewController based on a one-to-one relationship with the managed view.
- Provides encapsulation to make nesting views reliable.
- Retains the ability to select components and listen to their events at any level below the associated view.

### Listeners

For the purposes of ViewControllers, we can look at just two examples. The first is a basic use of a listeners config on a child item in a view:

Sample Code

    Ext.define('MyApp.view.foo.Foo', {
        extend: 'Ext.panel.Panel',
        xtype: 'foo',
        controller: 'foo',

        items: [{
            xtype: 'textfield',
            fieldLabel: 'Bar',
            listeners: {
                change: 'onBarChange'  // no scope given here
            }
        }]
    });

    Ext.define('MyApp.view.foo.FooController', {
        extend: 'Ext.app.ViewController',
        alias: 'controller.foo',

        onBarChange: function (barTextField) {
            // called by 'change' event
        }
    });

The above use of listeners shows a named event handler (`onBarChange`) with no specified “scope”. Internally, the event system resolves the default scope for the Bar textfield to its owning ViewController.

Historically, the listeners config was reserved for use by a component’s creator, so how would a view listen to its own events, or perhaps those fired by its base class? The answer is that we need to use an explicit scope:

Sample Code

    Ext.define('MyApp.view.foo.Foo', {
        extend: 'Ext.panel.Panel',
        xtype: 'foo',
        controller: 'foo',

        listeners: {
            collapse: 'onCollapse',
            scope: 'controller'
        },

        items: [{
            ...
        }]
    });

The above example leverages two new features in Ext JS: named scopes and declarative listeners. We’ll focus on the named scope here. There are two valid values for named scope: “this” and “controller”. When writing MVC applications, we almost always use “controller” which has the obvious result of looking on that view’s ViewController (not the ViewController of the view that created the instance).

Since a view is a type of Ext.Component, we have assigned this view an “xtype” which enables other views to create an instance of our view in the same way this view created its textfield. To see how this comes together, consider a view that uses this one. For example:

Sample Code

    Ext.define('MyApp.view.bar.Bar', {
        extend: 'Ext.panel.Panel',
        xtype: 'bar',
        controller: 'bar',

        items: [{
            xtype: 'foo',
            listeners: {
                collapse: 'onCollapse'
            }
        }]
    });

In this case, the Bar view is creating an instance of the Foo view as one of its items. Further, it is listening to the collapse event just like the Foo view. The listeners declared by the Foo view will fire on Foo’s ViewController while the listeners declared in the Bar view will fire on Bar’s ViewController.

### Reference

One of the most common loose ends when writing controller logic is getting ahold of the necessary components to complete a particular action. Something as simple as:

Sample Code

    Ext.define('MyApp.view.foo.Foo', {
        extend: 'Ext.panel.Panel',
        xtype: 'foo',
        controller: 'foo',

        tbar: [{
            xtype: 'button',
            text: 'Add',
            handler: 'onAdd'
        }],

        items: [{
            xtype: 'grid',
            ...
        }]
    });

    Ext.define('MyApp.view.foo.FooController', {
        extend: 'Ext.app.ViewController',
        alias: 'controller.foo',

        onAdd: function () {
            // ... get the grid and add a record ...
        }
    });

But how should one acquire the grid component? All techniques require you to place some recognizable property on the grid to allow it to be uniquely identified. Older techniques used the “id” config (and getCmp) or the “itemId” config (using “refs” or some component query method). The advantage of “id” is fast lookup, but since these identifiers must be unique across the entire application and the DOM as well, this is not often desirable. Using “itemId” and some form of query is more flexible, but it’s necessary to perform a search to find the desired component.

Using the `reference` config, we simply add the “reference” to the grid and use `lookupReference` to get at it:

Sample Code

    Ext.define('MyApp.view.foo.Foo', {
        extend: 'Ext.panel.Panel',
        xtype: 'foo',
        controller: 'foo',

        tbar: [{
            xtype: 'button',
            text: 'Add',
            handler: 'onAdd'
        }],

        items: [{
            xtype: 'grid',
            reference: 'fooGrid'
            ...
        }]
    });

    Ext.define('MyApp.view.foo.FooController', {
        extend: 'Ext.app.ViewController',
        alias: 'controller.foo',

        onAdd: function () {
            var grid = this.lookupReference('fooGrid');
        }
    });

This is similar to assigning an itemId of “fooGrid” and doing: “this.down(‘#fooGrid’)”. The difference under the hood, however, is quite significant. First, a reference config instructs the component to register itself with its owning view (identified by the presence of a ViewController in this case). Second, the `lookupReference` method simply consults the cache to see if references need to be refreshed (say due to add or remove on a container). If all is well, it just returns the reference from the cache. Or, in pseudo-code:

Sample Code

    lookupReference: (reference) {
        var cache = this.references;
        if (!cache) {
            Ext.fixReferences(); // fix all references
            cache = this.references; // now the cache is valid
        }
        return cache[reference];
    }

In other words, there is no search and the linkages damaged by adding or removing items from containers are fixed in one go, when they are needed. As we will see below, this approach has benefits other than efficiency.

### Encapsulation

The use of selectors along with the controller `refs` config was very flexible, but at the same time had certain risks. The fact that these selectors “see” everything at all levels of the component hierarchy is both powerful and prone to mistakes. For example, a controller could be working 100% when it runs in isolation but then fails as soon as other views are introduced because its selectors have undesired matches with the new view.

These problems can be managed by following certain practices, but when using listeners and references with a ViewController these problems are simply not possible. This is because the listeners and reference configs connect only with their owning ViewController. Views are free to chose any reference value that is unique within that view knowing that these names will not be exposed to the view’s creator.

Likewise, listeners are resolved on their owning ViewController and cannot be accidentally dispatched to event handlers in other controllers with errant selectors. While listeners are often preferable to selectors, the two mechanisms play well together for those situations where a selector-based approach is desired.

To complete this model, views need to fire events that can be consumed by their owning view’s ViewController. There is a helper method in ViewController for this purpose: `fireViewEvent`. For example:

Sample Code

    Ext.define('MyApp.view.foo.FooController', {
        extend: 'Ext.app.ViewController',
        alias: 'controller.foo',

        onAdd: function () {
            var record = new MyApp.model.Thing();
            var grid = this.lookupReference('fooGrid');
            grid.store.add(record);

            this.fireViewEvent('addrecord', this, record);
        }
    });

This enables the standard form of listener for the creator of this view:

Sample Code

    Ext.define('MyApp.view.bar.Bar', {
        extend: 'Ext.panel.Panel',
        xtype: 'bar',
        controller: 'bar',

        items: [{
            xtype: 'foo',
            listeners: {
                collapse: 'onCollapse',
                addrecord: 'onAddRecord'
            }
        }]
    });

### Listeners and Event Domains

In Ext JS 4.2, the MVC event dispatcher was generalized with the introduction of event domains. These event domains intercepted events as they were fired and dispatched them to controllers controlled by selector matching. The “component” event domain had full component query selectors while the other domains had more limited selectors.

With Ext JS 5+, each ViewController creates an instance of a new type of event domain called the “view” event domain. This event domain allows ViewControllers to use the standard `listen` and `control` methods while limiting their scope implicitly to their view. It also adds a special selector to match the view itself:

Sample Code

    Ext.define('MyApp.view.foo.FooController', {
        extend: 'Ext.app.ViewController',
        alias: 'controller.foo',

        control: {
            '#': {  // matches the view itself
                collapse: 'onCollapse'
            },
            button: {
                click: 'onAnyButtonClick'
            }
        }
    });

The key difference between listeners and selectors can be seen above. The “button” selector will match any button in this view or any child view, irrespective of depth, even if that button belongs to a great-grandchild view. In other words, selector-based handlers do not respect encapsulation boundaries. This behavior is consistent with previous Ext.app.Controller behavior and can be a useful technique in limited situations.

Lastly, these event domains respect nesting and effectively “bubble” an event up the view hierarchy. That is to say, when an event fires, it’s first delivered to any standard listeners. Then, it’s delivered to its owning ViewController, followed by its parent ViewController (if any) on up the hierarchy. Eventually, the event is delivered to the standard “component” event domain to be handled by Ext.app.Controller-derived controllers.

### Life cycle

A common technique with large applications is to dynamically create controllers when they are first needed. This could help reduce the load time of the application and help runtime performance as well by not activating all potential controllers. The limitation to this in previous versions was that, once created, these controllers would remain active in the application. It was not possible to destroy them and release their resources. Likewise, this did not change the reality that a controller could have any number of associated views (including none).

The ViewController, however, is created very early in the component’s lifecycle and is bound to that view for its entire lifetime. When that view is destroyed, the ViewController is likewise destroyed. This means that the ViewController is no longer forced to manage states where there is no view or many views.

This one-to-one relationship means reference tracking is simplified and no longer prone to leaking destroyed components. A ViewController can implement any of these methods to perform tasks at key points in its lifecycle:

- beforeInit - This method can be overridden in order to operate on the view prior to its initComponent method being called. This method is called immediately after the controller is created, which occurs during initConfig called from the Component constructor.
- init - Called shortly after initComponent has been called on the view. This is the typical time to perform initialization for the controller now that the view is initialized.
- initViewModel - Called when the view’s ViewModel is created (if one is defined).
- destroy - Cleanup and return resources (be sure to call `callParent`).

## Conclusion

We think ViewControllers will greatly streamline your MVC applications. They also work very well with ViewModels, so you can combine these approaches and their respective strengths. We’re excited about the upcoming release and seeing these improvements at work in your applications.

## Ext JS 6.2.0 - Modern Toolkit

## Ext JS

### 6.x

6.2.0 EA (classic) (modern)
6.0.2 (classic) (modern)
6.0.1 (classic) (modern)
6.0.0 (classic) (modern)

### 5.x

5.1.3 5.1.2 5.1.1 5.1.0 5.0.1 5.0.0

### 4.x

4.2.5 4.1.3 4.0.7

### 3.x

3.4.0

## Sencha Test

Sencha Test

## Cmd

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## GXT

4.x 3.x

## IDE Plugins

IDE Plugins

## Sencha Inspector

Sencha Inspector

## Architect

Architect 3 Architect 4 EA

## Touch

### 2.x

Touch 2.4 Touch 2.3 Touch 2.2 Touch 2.0

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