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.
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.
static
label next to the
method name. *See Static below.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).
Let's look at each part of the member row:
lookupComponent
in this example)( item )
in this example)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
).PROTECTED
in
this example - see the Flags section below)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.view source
in the example)item : Object
in the example).undefined
a "Returns" section
will note the type of class or object returned and a description (Ext.Component
in the
example)Available since 3.4.0
- not pictured in
the example) just after the member descriptionDefaults to: false
)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.
classInstance.method1().method2().etc();
false
is returned from
an event handler- 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
- 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
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.
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.
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.
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.
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:
Ext.button.Button
class has an alternate class name of Ext.Button
). Alternate class
names are commonly maintained for backward compatibility.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.
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:
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.
Represents a 2D point with x and y properties, useful for comparison and instantiation from an event:
var point = Ext.util.Point.fromEvent(e);
The value true
causes config
values to be stored on instances using a
property name prefixed with an underscore ("_") character. A value of false
stores config
values as properties using their exact name (no prefix).
Defaults to:
true
Available since: 5.0.0
The value true
instructs the initConfig
method to only honor values for
properties declared in the config
block of a class. When false
, properties
that are not declared in a config
block will be placed on the instance.
Defaults to:
true
Available since: 5.0.0
Setting this property to false
will prevent nulling object references
on a Class instance after destruction. Setting this to "async"
will delay
the clearing for approx 50ms.
Defaults to:
true
Available since: 6.2.0
Setting this property to true
will result in setting the object's
prototype to null
after the destruction sequence is fully completed.
After that, most attempts at calling methods on the object instance
will result in "method not defined" exception. This can be very helpful
with tracking down otherwise hard to find bugs like runaway Ajax requests,
timed functions not cleared on destruction, etc.
Note that this option can only work in browsers that support Object.setPrototypeOf
method, and is only available in debugging mode.
Defaults to:
false
Available since: 6.2.0
This property is set to true
after the destroy
method is called.
Defaults to:
false
This property is set to true
during the call to initConfig
.
Defaults to:
false
Available since: 5.0.0
This property is set to true
if this instance is the first of its class.
Defaults to:
false
Available since: 5.0.0
This value is true
and is used to identify plain objects from instances of
a defined class.
Defaults to:
true
Get the reference to the current class from which this object was instantiated. Unlike Ext.Base#statics,
this.self
is scope-dependent and it's meant to be used for dynamic inheritance. See Ext.Base#statics
for a detailed comparison
Ext.define('My.Cat', {
statics: {
speciesName: 'Cat' // My.Cat.speciesName = 'Cat'
},
constructor: function() {
alert(this.self.speciesName); // dependent on 'this'
},
clone: function() {
return new this.self();
}
});
Ext.define('My.SnowLeopard', {
extend: 'My.Cat',
statics: {
speciesName: 'Snow Leopard' // My.SnowLeopard.speciesName = 'Snow Leopard'
}
});
var cat = new My.Cat(); // alerts 'Cat'
var snowLeopard = new My.SnowLeopard(); // alerts 'Snow Leopard'
var clone = snowLeopard.clone();
alert(Ext.getClassName(clone)); // alerts 'My.SnowLeopard'
Defaults to:
Base
This method applies a versioned, deprecation declaration to this class. This
is typically called by the deprecated
config.
deprecations : Object
Modifies the current region to be adjusted by offsets.
top : Number
Top offset
right : Number
Right offset
bottom : Number
Bottom offset
left : Number
Left offset
this
Returns the Region to which this rectangle should be moved in order to have the desired alignment with the specified target while remaining within the constraint.
The align
option can be one of these forms:
t
/r
/b
/l
) followed by a percentage along that side. This describes a
point to align with a similar point in the target. So 't0-b0'
would be
the same as 'tl-bl'
, 'l0-r50'
would place the top left corner of this item
halfway down the right edge of the target item. This allows more flexibility
and also describes which two edges are considered adjacent when positioning an anchor.If the inside
option is passed, the Region will attempt to align as specified,
but the position will be adjusted to constrain to the inside
Region if necessary.
Note that the Region being aligned might be swapped to align to a different position
than that specified in order to enforce the constraints. Following are all of the
supported anchor positions:
Value Description
----- -----------------------------
tl The top left corner
t The center of the top edge
tr The top right corner
l The center of the left edge
c The center
r The center of the right edge
bl The bottom left corner
b The center of the bottom edge
br The bottom right corner
Example Usage:
var xy = comp.getRegion().alignTo({
align: 't-b', // align comp's top/center to el's bottom/center
target: el.getRegion(),
anchorSize: new Ext.util.Point(10, 10),
inside: new Ext.util.Region(0, Ext.Element.getViewportWidth(), Ext.Element.getViewportHeight(), 0)
});
options : Object
The alignment options.
target : Ext.util.Region
The rectangle to which this rectangle should align.
align : String (optional)
The alignment descriptor for positioning this
rectangle with respect to the target
. See Ext.util.Positionable#alignTo.
Note that if the requested alignment results in violation of the inside
constraint,
the result will be flipped align to the closest edge which conforms to the constraint.
Defaults to:
tl-bl
position : Array / Ext.util.Position (optional)
The position at which to place the
resulting region before being excluded from the target area and aligned to the closest
edge which allows conformity with any passed inside
option. Used instead of the align
option.
offset : Ext.util.Offset / Number[] (optional)
An extra exclusion zone round the target.
anchorSize : Ext.util.Offset / Number[] (optional)
The width and height of any external anchor
element. This is used to calculate the true bounds of the Region inclusive of the anchor.
The x
dimension is the height of the arrow in all orientations, and the y
dimension
is the width of the baseline of the arrow in all dimensions.
If this option is used, and the returned region successfully clears the
bounds of the target, then the anchor region will be returned in the return value
as the anchor
property. This will in turn have a position
property which will
be 'top'
, 'left
, 'right'
, or 'bottom'
.
overlap : Boolean (optional)
Pass true
to allow this rectangle to overlap
the target.
rtl : Boolean (optional)
Pass true
to swap left/right alignment.
inside : Ext.util.Region (optional)
The rectangle to which this rectangle is constrained.
minHeight : Number (optional)
Used when this Region is to be aligned directly below or above the target. Gives the option to reduce the height to fit in the available space.
axisLock : Boolean (optional)
If true
, then fallback on constraint violation will
only take place along the major align axis. That is, if align: "l-r"
is being used, and
axisLock: true
is used, then if constraints fail, only fallback to r-l
is considered.
The Region that will align this rectangle. Note that if
a minHeight
option was passed, and aligment is either above or below the target,
the Region might be reduced to fit within the space.
Call the original method that was previously overridden with Ext.Base#override
Ext.define('My.Cat', {
constructor: function() {
alert("I'm a cat!");
}
});
My.Cat.override({
constructor: function() {
alert("I'm going to be a cat!");
this.callOverridden();
alert("Meeeeoooowwww");
}
});
var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
// alerts "I'm a cat!"
// alerts "Meeeeoooowwww"
args : Array/Arguments
The arguments, either an array or the arguments
object
from the current method, for example: this.callOverridden(arguments)
Returns the result of calling the overridden method
Deprecated since version 4.1.0
Use method-callParent instead.
Call the "parent" method of the current method. That is the method previously overridden by derivation or by an override (see Ext#define).
Ext.define('My.Base', {
constructor: function (x) {
this.x = x;
},
statics: {
method: function (x) {
return x;
}
}
});
Ext.define('My.Derived', {
extend: 'My.Base',
constructor: function () {
this.callParent([21]);
}
});
var obj = new My.Derived();
alert(obj.x); // alerts 21
This can be used with an override as follows:
Ext.define('My.DerivedOverride', {
override: 'My.Derived',
constructor: function (x) {
this.callParent([x*2]); // calls original My.Derived constructor
}
});
var obj = new My.Derived();
alert(obj.x); // now alerts 42
This also works with static and private methods.
Ext.define('My.Derived2', {
extend: 'My.Base',
// privates: {
statics: {
method: function (x) {
return this.callParent([x*2]); // calls My.Base.method
}
}
});
alert(My.Base.method(10)); // alerts 10
alert(My.Derived2.method(10)); // alerts 20
Lastly, it also works with overridden static methods.
Ext.define('My.Derived2Override', {
override: 'My.Derived2',
// privates: {
statics: {
method: function (x) {
return this.callParent([x*2]); // calls My.Derived2.method
}
}
});
alert(My.Derived2.method(10); // now alerts 40
To override a method and replace it and also call the superclass method, use method-callSuper. This is often done to patch a method to fix a bug.
args : Array/Arguments
The arguments, either an array or the arguments
object
from the current method, for example: this.callParent(arguments)
Returns the result of calling the parent method
This method is used by an override to call the superclass method but bypass any overridden method. This is often done to "patch" a method that contains a bug but for whatever reason cannot be fixed directly.
Consider:
Ext.define('Ext.some.Class', {
method: function () {
console.log('Good');
}
});
Ext.define('Ext.some.DerivedClass', {
extend: 'Ext.some.Class',
method: function () {
console.log('Bad');
// ... logic but with a bug ...
this.callParent();
}
});
To patch the bug in Ext.some.DerivedClass.method
, the typical solution is to create an
override:
Ext.define('App.patches.DerivedClass', {
override: 'Ext.some.DerivedClass',
method: function () {
console.log('Fixed');
// ... logic but with bug fixed ...
this.callSuper();
}
});
The patch method cannot use method-callParent to call the superclass
method
since that would call the overridden method containing the bug. In
other words, the above patch would only produce "Fixed" then "Good" in the
console log, whereas, using callParent
would produce "Fixed" then "Bad"
then "Good".
args : Array/Arguments
The arguments, either an array or the arguments
object
from the current method, for example: this.callSuper(arguments)
Returns the result of calling the superclass method
Modifies the current region to be constrained to the targetRegion.
targetRegion : Ext.util.Region
this
Creates point on 2D plane.
x : Number (optional)
X coordinate.
Defaults to: 0
y : Number (optional)
Y coordinate.
Defaults to: 0
Checks if this region completely contains the region or point that is passed in.
region : Ext.util.Region/Ext.util.Point
Clones this Point.
The new point.
Deprecated since version 2.0.0
Please use clone instead.
Copy the x
and y
values of another point / object to this point itself.
point : Ext.util.Point/Object
This point.
This method is called to cleanup an object and its resources. After calling this method, the object should not be used any further in any way, including access to its methods and properties.
To prevent potential memory leaks, all object references will be nulled
at the end of destruction sequence, unless clearPropertiesOnDestroy
is set to false
.
Compare this point and another point.
point : Ext.util.Point/Object
The point to compare with, either an instance
of Ext.util.Point or an object with x
and y
properties.
Returns whether they are equivalent.
This method pushes the "other" Region out of this region via the shortest translation. If an "inside" Region is passed, the exclusion also honours that constraint.
other : Region
The Region to move so that it does not intersect this Region.
inside : Region
A Region into which the other Region must be constrained.
minHeight : Number (optional)
If passed, indicates that the height may be reduced up to a point to fit the "other" region below or above the target but within the "inside" Region.
allowX : Boolean (optional)
Pass false
to disallow translation along the X axis.
Defaults to: true
allowY : Boolean (optional)
Pass false
to disallow translation along the Y axis.
Defaults to: true
The edge it is now aligned to, 0=top, 1=right, 2=bottom, 3=left.
Returns a specified config property value. If the name parameter is not passed, all current configuration options will be returned as key value pairs.
name : String (optional)
The name of the config property to get.
peek : Boolean (optional)
true
to peek at the raw value without calling the getter.
Defaults to: false
The config property value.
Returns the initial configuration passed to the constructor when instantiating this class.
Given this example Ext.button.Button definition and instance:
Ext.define('MyApp.view.Button', {
extend: 'Ext.button.Button',
xtype: 'mybutton',
scale: 'large',
enableToggle: true
});
var btn = Ext.create({
xtype: 'mybutton',
renderTo: Ext.getBody(),
text: 'Test Button'
});
Calling btn.getInitialConfig()
would return an object including the config
options passed to the create
method:
xtype: 'mybutton',
renderTo: // The document body itself
text: 'Test Button'
Calling btn.getInitialConfig('text')
returns 'Test Button'.
name : String (optional)
Name of the config option to return.
The full config object or a single config value
when name
parameter specified.
Returns the offsets of this region from the passed region or point.
offsetsTo : Ext.util.Region/Ext.util.Point
The region or point to get get the offsets from.
The XY page offsets
Get the offset amount of a point outside the region
axis : String (optional)
p : Ext.util.Point (optional)
the point
Get the offset amount on the x-axis
p : Number
the offset
Get the offset amount on the y-axis
p : Number
the offset
Get the width / height of this region
an object with width and height properties
Initialize configuration for this class. a typical example:
Ext.define('My.awesome.Class', {
// The default config
config: {
name: 'Awesome',
isAwesome: true
},
constructor: function(config) {
this.initConfig(config);
}
});
var awesome = new My.awesome.Class({
name: 'Super Awesome'
});
alert(awesome.getName()); // 'Super Awesome'
instanceConfig : Object
this
Checks if this region intersects the region passed in.
region : Ext.util.Region
Returns the intersected region or false if there is no intersection.
Returns true
if the passed point is within a certain distance of this point.
point : Ext.util.Point/Object
The point to check with, either an instance
of Ext.util.Point or an object with x
and y
properties.
threshold : Object/Number
Can be either an object with x
and y
properties or a number.
Determins whether this Point contained by the passed Region, Component or element.
region : Ext.util.Region/Ext.Component/Ext.dom.Element/HTMLElement
The rectangle to check that this Point is within.
Check whether the point / offset is out of bound
axis : String (optional)
p : Ext.util.Point/Number (optional)
the point / offset
Check whether the offset is out of bound in the x-axis
p : Number
the offset
Check whether the offset is out of bound in the y-axis
p : Number
the offset
Returns true
if this point is close to another one.
Deprecated since version 2.0.0
Please use isCloseTo instead.
Adds a "destroyable" object to an internal list of objects that will be destroyed
when this instance is destroyed (via destroy
).
name : String
value : Object
The value
passed.
Restrict a point within the region by a certain factor.
axis : String (optional)
p : Ext.util.Point/Ext.util.Offset/Object (optional)
factor : Number (optional)
Restrict an offset within the region by a certain factor, on the x-axis
p : Number
factor : Number (optional)
The factor.
Defaults to: 1
Restrict an offset within the region by a certain factor, on the y-axis
p : Number
factor : Number (optional)
The factor, defaults to 1
Round all the properties of this region
this This Region
Compare this point with another point when the x
and y
values of both points are rounded. For example:
[100.3,199.8] will equals to [100, 200].
point : Ext.util.Point/Object
The point to compare with, either an instance
of Ext.util.Point or an object with x
and y
properties.
Sets a single/multiple configuration options.
name : String/Object
The name of the property to set, or a set of key value pairs to set.
value : Object (optional)
The value to set for the name parameter.
this
Translates this Region to the specified position
x : Number
The new X position.
y : Number
The new Y position.
This region after translation.
Get the reference to the class from which this object was instantiated. Note that unlike Ext.Base#self,
this.statics()
is scope-independent and it always returns the class from which it was called, regardless of what
this
points to during run-time
Ext.define('My.Cat', {
statics: {
totalCreated: 0,
speciesName: 'Cat' // My.Cat.speciesName = 'Cat'
},
constructor: function() {
var statics = this.statics();
alert(statics.speciesName); // always equals to 'Cat' no matter what 'this' refers to
// equivalent to: My.Cat.speciesName
alert(this.self.speciesName); // dependent on 'this'
statics.totalCreated++;
},
clone: function() {
var cloned = new this.self(); // dependent on 'this'
cloned.groupName = this.statics().speciesName; // equivalent to: My.Cat.speciesName
return cloned;
}
});
Ext.define('My.SnowLeopard', {
extend: 'My.Cat',
statics: {
speciesName: 'Snow Leopard' // My.SnowLeopard.speciesName = 'Snow Leopard'
},
constructor: function() {
this.callParent();
}
});
var cat = new My.Cat(); // alerts 'Cat', then alerts 'Cat'
var snowLeopard = new My.SnowLeopard(); // alerts 'Cat', then alerts 'Snow Leopard'
var clone = snowLeopard.clone();
alert(Ext.getClassName(clone)); // alerts 'My.SnowLeopard'
alert(clone.groupName); // alerts 'Cat'
alert(My.Cat.totalCreated); // alerts 3
Returns a human-eye-friendly string that represents this point, useful for debugging.
For example Point[12,8]
.
Alias for translateBy Translate this Region by the given offset amount
x : Ext.util.Offset/Object
Object containing the x
and y
properties.
Or the x value is using the two argument form.
y : Number
The y value unless using an Offset object.
this This Region
Translate this Region by the given offset amount
x : Ext.util.Offset/Object
Object containing the x
and y
properties.
Or the x value is using the two argument form.
y : Number
The y value unless using an Offset object.
this This Region
Returns the smallest region that contains the current AND targetRegion.
region : Ext.util.Region
a new region
Adds new config properties to this class. This is called for classes when they are declared, then for any mixins that class may define and finally for any overrides defined that target the class.
config : Object
mixinClass : Ext.Class (optional)
The mixin class if the configs are from a mixin.
Add methods / properties to the prototype of this class.
Ext.define('My.awesome.Cat', {
constructor: function() {
...
}
});
My.awesome.Cat.addMembers({
meow: function() {
alert('Meowww...');
}
});
var kitty = new My.awesome.Cat();
kitty.meow();
members : Object
The members to add to this class.
isStatic : Boolean (optional)
Pass true
if the members are static.
Defaults to: false
privacy : Boolean (optional)
Pass true
if the members are private. This
only has meaning in debug mode and only for methods.
Defaults to: false
Add / override static properties of this class.
Ext.define('My.cool.Class', {
...
});
My.cool.Class.addStatics({
someProperty: 'someValue', // My.cool.Class.someProperty = 'someValue'
method1: function() { ... }, // My.cool.Class.method1 = function() { ... };
method2: function() { ... } // My.cool.Class.method2 = function() { ... };
});
members : Object
this
Borrow another class' members to the prototype of this class.
Ext.define('Bank', {
money: '$$$',
printMoney: function() {
alert('$$$$$$$');
}
});
Ext.define('Thief', {
...
});
Thief.borrow(Bank, ['money', 'printMoney']);
var steve = new Thief();
alert(steve.money); // alerts '$$$'
steve.printMoney(); // alerts '$$$$$$$'
fromClass : Ext.Base
The class to borrow members from
members : Array/String
The names of the members to borrow
this
Create a new instance of this Class.
Ext.define('My.cool.Class', {
...
});
My.cool.Class.create({
someConfig: true
});
All parameters are passed to the constructor of the class.
the created instance.
Create aliases for existing prototype methods. Example:
Ext.define('My.cool.Class', {
method1: function() { ... },
method2: function() { ... }
});
var test = new My.cool.Class();
My.cool.Class.createAlias({
method3: 'method1',
method4: 'method2'
});
test.method3(); // test.method1()
My.cool.Class.createAlias('method5', 'method3');
test.method5(); // test.method3() -> test.method1()
alias : String/Object
The new method name, or an object to set multiple aliases. See flexSetter
origin : String/Object
The original method name
Returns a new point from an object that has x
and y
properties, if that object is not an instance
of Ext.util.Point. Otherwise, returns the given point itself.
object : Object
Returns a new instance of Ext.util.Point based on the pageX
/ pageY
values of the given event.
e : Event
The event.
Returns a new instance of Ext.util.Point based on the pageX
/ pageY
values of the given touch.
touch : Event
Returns the Ext.Configurator
for this class.
Get the current class' name in string format.
Ext.define('My.cool.Class', {
constructor: function() {
alert(this.self.getName()); // alerts 'My.cool.Class'
}
});
My.cool.Class.getName(); // 'My.cool.Class'
className
Used internally by the mixins pre-processor
name : Object
mixinClass : Object
Override members of this class. Overridden methods can be invoked via Ext.Base#callParent.
Ext.define('My.Cat', {
constructor: function() {
alert("I'm a cat!");
}
});
My.Cat.override({
constructor: function() {
alert("I'm going to be a cat!");
this.callParent(arguments);
alert("Meeeeoooowwww");
}
});
var kitty = new My.Cat(); // alerts "I'm going to be a cat!"
// alerts "I'm a cat!"
// alerts "Meeeeoooowwww"
Direct use of this method should be rare. Use Ext.define instead:
Ext.define('My.CatOverride', {
override: 'My.Cat',
constructor: function() {
alert("I'm going to be a cat!");
this.callParent(arguments);
alert("Meeeeoooowwww");
}
});
The above accomplishes the same result but can be managed by the Ext.Loader which can properly order the override and its target class and the build process can determine whether the override is needed based on the required state of the target class (My.Cat).
members : Object
The properties to add to this class. This should be specified as an object literal containing one or more properties.
this class