Ember.ApplicationInstance Class
The ApplicationInstance
encapsulates all of the stateful aspects of a
running Application
.
At a high-level, we break application boot into two distinct phases:
- Definition time, where all of the classes, templates, and other dependencies are loaded (typically in the browser).
- Run time, where we begin executing the application once everything has loaded.
Definition time can be expensive and only needs to happen once since it is an idempotent operation. For example, between test runs and FastBoot requests, the application stays the same. It is only the state that we want to reset.
That state is what the ApplicationInstance
manages: it is responsible for
creating the container that contains all application state, and disposing of
it once the particular test run or FastBoot request has finished.
Item Index
Methods
- _lazyInjections
- _lookupFactory
- _onLookup
- _resolveLocalLookupName
- _scheduledDestroy
- addObserver
- beginPropertyChanges
- boot
- buildChildEngineInstance
- cacheFor
- cloneParentDependencies
- decrementProperty
- destroy
- endPropertyChanges
- get
- getProperties
- getWithDefault
- hasObserverFor
- hasRegistration
- incrementProperty
- init
- inject
- lookup
- notifyPropertyChange
- ownerInjection
- propertyDidChange
- propertyWillChange
- register
- registeredOption
- registeredOptions
- registeredOptionsForType
- registerOption
- registerOptions
- registerOptionsForType
- removeObserver
- reopen
- reopenClass
- resolveRegistration
- set
- setProperties
- setupRegistry
- toggleProperty
- toString
- unregister
- willDestroy
Methods
_lazyInjections
()
Object
private
Returns:
_lookupFactory
-
fullName
Parameters:
-
fullName
String
Returns:
_onLookup
()
private
_resolveLocalLookupName
-
fullName
-
source
Returns:
_scheduledDestroy
()
private
destroy
method.
addObserver
-
key
-
target
-
method
context
parameter:
`
javascript
fooDidChange: function(sender, key, value, rev) { };
`
The sender is the object that changed. The key is the property that
changes. The value property is currently reserved and unused. The rev
is the last property revision of the object when it changed, which you can
use to detect if the key value has really changed or not.
If you pass a context
parameter, the context will be passed before the
revision like so:
`
javascript
fooDidChange: function(sender, key, value, context, rev) { };
`
Usually you will not need the value, context or revision parameters at
the end. In this case, it is common to write observer methods that take
only a sender and key value as parameters or, if you aren't interested in
any of these values, to write an observer that has no parameters at all.
beginPropertyChanges
()
Ember.Observable
private
endPropertyChanges()
to deliver the deferred change notifications and end
deferring.
Returns:
boot
-
options
Ember.EngineInstance
and return a promise that resolves
with the instance itself when the boot process is complete.
The primary task here is to run any registered instance initializers.
See the documentation on BootOptions
for the options it takes.
Parameters:
-
options
Object
Returns:
buildChildEngineInstance
-
name
-
options
Ember.EngineInstance
that's a child of this instance.
Engines must be registered by name with their parent engine
(or application).
Parameters:
-
name
Stringthe registered name of the engine. -
options
Objectoptions provided to the engine instance.
Returns:
cacheFor
-
keyName
Parameters:
-
keyName
String
Returns:
cloneParentDependencies
()
private
decrementProperty
-
keyName
-
decrement
`
javascript
player.decrementProperty('lives');
orc.decrementProperty('health', 5);
`
Parameters:
-
keyName
StringThe name of the property to decrement -
decrement
NumberThe amount to decrement by. Defaults to 1
Returns:
destroy
()
Ember.Object
public
isDestroyed
flag and removing its
metadata, which effectively destroys observers and bindings.
If you try to set a property on a destroyed object, an exception will be
raised.
Note that destruction is scheduled for the end of the run loop and does not
happen immediately. It will set an isDestroying flag immediately.
Returns:
endPropertyChanges
()
Ember.Observable
private
beginPropertyChanges()
at the beginning of the changes to defer change
notifications. When you are done making changes, call this method to
deliver the deferred change notifications and end deferring.
Returns:
get
-
keyName
object[keyName]
or object.keyName
,
however it supports both computed properties and the unknownProperty
handler.
Because get
unifies the syntax for accessing all these kinds
of properties, it can make many refactorings easier, such as replacing a
simple property with a computed property, or vice versa.
### Computed Properties
Computed properties are methods defined with the property
modifier
declared at the end, such as:
`
javascript
fullName: Ember.computed('firstName', 'lastName', function() {
return this.get('firstName') + ' ' + this.get('lastName');
})
`
When you call get
on a computed property, the function will be
called and the return value will be returned instead of the function
itself.
### Unknown Properties
Likewise, if you try to call get
on a property whose value is
undefined
, the unknownProperty()
method will be called on the object.
If this method returns any value other than undefined
, it will be returned
instead. This allows you to implement "virtual" properties that are
not defined upfront.
Parameters:
-
keyName
StringThe property to retrieve
Returns:
getProperties
-
list
getProperties
with a list of strings or an array:
`
javascript
record.getProperties('firstName', 'lastName', 'zipCode');
// { firstName: 'John', lastName: 'Doe', zipCode: '10011' }
`
is equivalent to:
`
javascript
record.getProperties(['firstName', 'lastName', 'zipCode']);
// { firstName: 'John', lastName: 'Doe', zipCode: '10011' }
`
Parameters:
-
list
String... | Arrayof keys to get
Returns:
getWithDefault
-
keyName
-
defaultValue
undefined
.
`
javascript
person.getWithDefault('lastName', 'Doe');
`
Parameters:
-
keyName
StringThe name of the property to retrieve -
defaultValue
ObjectThe value to return if the property value is undefined
Returns:
hasObserverFor
-
key
true
if the object currently has observers registered for a
particular key. You can use this method to potentially defer performing
an expensive action until someone begins observing a particular property
on the object.
Parameters:
-
key
StringKey to check
Returns:
hasRegistration
-
fullName
Parameters:
-
fullName
String
Returns:
incrementProperty
-
keyName
-
increment
`
javascript
person.incrementProperty('age');
team.incrementProperty('score', 2);
`
Parameters:
-
keyName
StringThe name of the property to increment -
increment
NumberThe amount to increment by. Defaults to 1
Returns:
init
()
public
`
javascript
const Person = Ember.Object.extend({
init() {
alert(Name is ${this.get('name')}
);
}
});
let steve = Person.create({
name: "Steve"
});
// alerts 'Name is Steve'.
`
NOTE: If you do override init
for a framework class like Ember.View
,
be sure to call this._super(...arguments)
in your
init
declaration! If you don't, Ember may not have an opportunity to
do important setup work, and you'll see strange behavior in your
application.
inject
-
factoryNameOrType
-
property
-
injectionName
`
javascript
let App = Ember.Application.create();
let Session = Ember.Object.extend({ isAuthenticated: false });
// A factory must be registered before it can be injected
App.register('session:main', Session);
// Inject 'session:main' onto all factories of the type 'controller'
// with the name 'session'
App.inject('controller', 'session', 'session:main');
App.IndexController = Ember.Controller.extend({
isLoggedIn: Ember.computed.alias('session.isAuthenticated')
});
`
Injections can also be performed on specific factories.
`
javascript
App.inject(`
It is important to note that injections can only be performed on
classes that are instantiated by Ember itself. Instantiating a class
directly (via create
or new
) bypasses the dependency injection
system.
**Note:** Ember-Data instantiates its models in a unique manner, and consequently
injections onto models (or all models) will not work as expected. Injections
on models can be enabled by setting EmberENV.MODEL_FACTORY_INJECTIONS
to true
.
lookup
-
fullName
-
options
`
javascript
let registry = new Registry();
let container = registry.container();
registry.register('api:twitter', Twitter);
let twitter = container.lookup('api:twitter');
twitter instanceof Twitter; // => true
// by default the container will return singletons
let twitter2 = container.lookup('api:twitter');
twitter2 instanceof Twitter; // => true
twitter === twitter2; //=> true
`
If singletons are not wanted an optional flag can be provided at lookup.
`
javascript
let registry = new Registry();
let container = registry.container();
registry.register('api:twitter', Twitter);
let twitter = container.lookup('api:twitter', { singleton: false });
let twitter2 = container.lookup('api:twitter', { singleton: false });
twitter === twitter2; //=> false
`
Parameters:
-
fullName
String -
options
Object
Returns:
notifyPropertyChange
-
keyName
propertyWillChange
and propertyDidChange
in
succession.
Parameters:
-
keyName
StringThe property key to be notified about.
Returns:
ownerInjection
()
Object
public
`
let owner = Ember.getOwner(this);
User.create(
owner.ownerInjection(),
{ username: 'rwjblue' }
)
`
Returns:
propertyDidChange
-
keyName
get()
or set()
on it. In this case, you can use this
method and propertyWillChange()
instead. Calling these two methods
together will notify all observers that the property has potentially
changed value.
Note that you must always call propertyWillChange
and propertyDidChange
as a pair. If you do not, it may get the property change groups out of
order and cause notifications to be delivered more often than you would
like.
Parameters:
-
keyName
StringThe property key that has just changed.
Returns:
propertyWillChange
-
keyName
get()
or set()
on it. In this case, you can use this
method and propertyDidChange()
instead. Calling these two methods
together will notify all observers that the property has potentially
changed value.
Note that you must always call propertyWillChange
and propertyDidChange
as a pair. If you do not, it may get the property change groups out of
order and cause notifications to be delivered more often than you would
like.
Parameters:
-
keyName
StringThe property key that is about to change.
Returns:
register
-
fullName
-
factory
-
options
inject
) or for service lookup. Each factory is registered with
a full name including two parts: type:name
.
A simple example:
`
javascript
let App = Ember.Application.create();
App.Orange = Ember.Object.extend();
App.register('fruit:favorite', App.Orange);
`
Ember will resolve factories from the App
namespace automatically.
For example App.CarsController
will be discovered and returned if
an application requests controller:cars
.
An example of registering a controller with a non-standard name:
`
javascript
let App = Ember.Application.create();
let Session = Ember.Controller.extend();
App.register('controller:session', Session);
// The Session controller can now be treated like a normal controller,
// despite its non-standard name.
App.ApplicationController = Ember.Controller.extend({
needs: ['session']
});
`
Registered factories are **instantiated** by having create
called on them. Additionally they are **singletons**, each time
they are looked up they return the same instance.
Some examples modifying that default behavior:
`
javascript
let App = Ember.Application.create();
App.Person = Ember.Object.extend();
App.Orange = Ember.Object.extend();
App.Email = Ember.Object.extend();
App.session = Ember.Object.create();
App.register('model:user', App.Person, { singleton: false });
App.register('fruit:favorite', App.Orange);
App.register('communication:main', App.Email, { singleton: false });
App.register('session', App.session, { instantiate: false });
`
registeredOption
-
fullName
-
optionName
Returns:
registeredOptions
-
fullName
Parameters:
-
fullName
String
Returns:
registeredOptionsForType
-
type
Parameters:
-
type
String
Returns:
registerOption
-
fullName
-
optionName
-
options
registerOptions
-
fullName
-
options
Parameters:
-
fullName
String -
options
Object
registerOptionsForType
-
type
-
options
`
javascript
let App = Ember.Application.create();
let appInstance = App.buildInstance();
// if all of type connection
must not be singletons
appInstance.registerOptionsForType('connection', { singleton: false });
appInstance.register('connection:twitter', TwitterConnection);
appInstance.register('connection:facebook', FacebookConnection);
let twitter = appInstance.lookup('connection:twitter');
let twitter2 = appInstance.lookup('connection:twitter');
twitter === twitter2; // => false
let facebook = appInstance.lookup('connection:facebook');
let facebook2 = appInstance.lookup('connection:facebook');
facebook === facebook2; // => false
`
Parameters:
-
type
String -
options
Object
removeObserver
-
key
-
target
-
method
addObserver()
and your
target will no longer receive notifications.
reopen
()
public
`
javascript
const MyObject = Ember.Object.extend({
name: 'an object'
});
o = MyObject.create();
o.get('name'); // 'an object'
MyObject.reopen({
say(msg){
console.log(msg);
}
})
o2 = MyObject.create();
o2.say("hello"); // logs "hello"
o.say("goodbye"); // logs "goodbye"
`
To add functions and properties to the constructor itself,
see reopenClass
reopenClass
()
public
`
javascript
const MyObject = Ember.Object.extend({
name: 'an object'
});
MyObject.reopenClass({
canBuild: false
});
MyObject.canBuild; // false
o = MyObject.create();
`
In other words, this creates static properties and functions for the class.
These are only available on the class and not on any instance of that class.
`
javascript
const Person = Ember.Object.extend({
name: "",
sayHello() {
alert("Hello. My name is " + this.get('name'));
}
});
Person.reopenClass({
species: "Homo sapiens",
createPerson(newPersonsName){
return Person.create({
name:newPersonsName
});
}
});
let tom = Person.create({
name: "Tom Dale"
});
let yehuda = Person.createPerson("Yehuda Katz");
tom.sayHello(); // "Hello. My name is Tom Dale"
yehuda.sayHello(); // "Hello. My name is Yehuda Katz"
alert(Person.species); // "Homo sapiens"
`
Note that species
and createPerson
are *not* valid on the tom
and yehuda
variables. They are only valid on Person
.
To add functions and properties to instances of
a constructor by extending the constructor's prototype
see reopen
resolveRegistration
-
fullName
Parameters:
-
fullName
String
Returns:
set
-
keyName
-
value
`
javascript
record.set("key", value);
`
This method is generally very similar to calling object["key"] = value
or
object.key = value
, except that it provides support for computed
properties, the setUnknownProperty()
method and property observers.
### Computed Properties
If you try to set a value on a key that has a computed property handler
defined (see the get()
method for an example), then set()
will call
that method, passing both the value and key instead of simply changing
the value itself. This is useful for those times when you need to
implement a property that is composed of one or more member
properties.
### Unknown Properties
If you try to set a value on a key that is undefined in the target
object, then the setUnknownProperty()
handler will be called instead. This
gives you an opportunity to implement complex "virtual" properties that
are not predefined on the object. If setUnknownProperty()
returns
undefined, then set()
will simply set the value on the object.
### Property Observers
In addition to changing the property, set()
will also register a property
change with the object. Unless you have placed this call inside of a
beginPropertyChanges()
and endPropertyChanges(),
any "local" observers
(i.e. observer methods declared on the same object), will be called
immediately. Any "remote" observers (i.e. observer methods declared on
another object) will be placed in a queue and called at a later time in a
coalesced manner.
Parameters:
-
keyName
StringThe property to set -
value
ObjectThe value to set ornull
.
Returns:
setProperties
-
hash
beginPropertyChanges
and endPropertyChanges
batch, so
observers will be buffered.
`
javascript
record.setProperties({ firstName: 'Charles', lastName: 'Jolley' });
`
Parameters:
-
hash
Objectthe hash of keys and values to set
Returns:
toggleProperty
-
keyName
`
javascript
starship.toggleProperty('warpDriveEngaged');
`
Parameters:
-
keyName
StringThe name of the property to toggle
Returns:
toString
()
String
public
toString
typically does, in a generic way for all Ember
objects.
`
javascript
const Person = Ember.Object.extend()
person = Person.create()
person.toString() //=> "`
If the object's class is not defined on an Ember namespace, it will
indicate it is a subclass of the registered superclass:
`
javascript
const Student = Person.extend()
let student = Student.create()
student.toString() //=> "<(subclass of Person):ember1025>"
`
If the method toStringExtension
is defined, its return value will be
included in the output.
`
javascript
const Teacher = Person.extend({
toStringExtension() {
return this.get('fullName');
}
});
teacher = Teacher.create()
teacher.toString(); //=> "`
Returns:
unregister
-
fullName
RegistryProxy#unregister
in order to clear any cached instances
of the unregistered factory.
Parameters:
-
fullName
String
willDestroy
()
public
Properties
__container__
Ember.Container
private
concatenatedProperties
Array
public
classNames
property of Ember.View
.
Here is some sample code showing the difference between a concatenated
property and a normal one:
`
javascript
const Bar = Ember.Object.extend({
// Configure which properties to concatenate
concatenatedProperties: ['concatenatedProperty'],
someNonConcatenatedProperty: ['bar'],
concatenatedProperty: ['bar']
});
const FooBar = Bar.extend({
someNonConcatenatedProperty: ['foo'],
concatenatedProperty: ['foo']
});
let fooBar = FooBar.create();
fooBar.get('someNonConcatenatedProperty'); // ['foo']
fooBar.get('concatenatedProperty'); // ['bar', 'foo']
`
This behavior extends to object creation as well. Continuing the
above example:
`
javascript
let fooBar = FooBar.create({
someNonConcatenatedProperty: ['baz'],
concatenatedProperty: ['baz']
})
fooBar.get('someNonConcatenatedProperty'); // ['baz']
fooBar.get('concatenatedProperty'); // ['bar', 'foo', 'baz']
`
Adding a single property that is not an array will just add it in the array:
`
javascript
let fooBar = FooBar.create({
concatenatedProperty: 'baz'
})
view.get('concatenatedProperty'); // ['bar', 'foo', 'baz']
`
Using the concatenatedProperties
property, we can tell Ember to mix the
content of the properties.
In Ember.Component
the classNames
, classNameBindings
and
attributeBindings
properties are concatenated.
This feature is available for you to use throughout the Ember object model,
although typical app developers are likely to use it infrequently. Since
it changes expectations about behavior of properties, you should properly
document its usage in each individual concatenated property (to not
mislead your users to think they can override the property in a subclass).
Default: null
customEvents
Object
private
The DOM events for which the event dispatcher should listen.
By default, the application's Ember.EventDispatcher
listens
for a set of standard DOM events, such as mousedown
and
keyup
, and delegates them to your application's Ember.View
instances.
isDestroyed
Unknown
public
true
the observers and bindings were already
removed by the effect of calling the destroy()
method.
Default: false
isDestroying
Unknown
public
destroy()
method has been called.
The object stays intact until the end of the run loop at which point
the isDestroyed
flag is set.
Default: false
mergedProperties
Array
public
queryParams
property of routes.
Here is some sample code showing the difference between a merged
property and a normal one:
`
javascript
const Bar = Ember.Object.extend({
// Configure which properties are to be merged
mergedProperties: ['mergedProperty'],
someNonMergedProperty: {
nonMerged: 'superclass value of nonMerged'
},
mergedProperty: {
page: {replace: false},
limit: {replace: true}
}
});
const FooBar = Bar.extend({
someNonMergedProperty: {
completelyNonMerged: 'subclass value of nonMerged'
},
mergedProperty: {
limit: {replace: false}
}
});
let fooBar = FooBar.create();
fooBar.get('someNonMergedProperty');
// => { completelyNonMerged: 'subclass value of nonMerged' }
//
// Note the entire object, including the nonMerged property of
// the superclass object, has been replaced
fooBar.get('mergedProperty');
// => {
// page: {replace: false},
// limit: {replace: false}
// }
//
// Note the page remains from the superclass, and the
// limit
property's value of false
has been merged from
// the subclass.
`
This behavior is not available during object create
calls. It is only
available at extend
time.
In Ember.Route
the queryParams
property is merged.
This feature is available for you to use throughout the Ember object model,
although typical app developers are likely to use it infrequently. Since
it changes expectations about behavior of properties, you should properly
document its usage in each individual merged property (to not
mislead your users to think they can override the property in a subclass).
Default: null
rootElement
String | DOMElement
private
The root DOM element of the Application as an element or a jQuery-compatible selector string.