Ember._HandlebarsBoundView Class
Ember._HandlebarsBoundView is a private view created by the Handlebars
{{bind}} helpers that is used to keep track of bound properties.
Every time a property is bound using a {{mustache}}, an anonymous subclass
of Ember._HandlebarsBoundView is created with the appropriate sub-template
and context set up. When the associated property changes, just the template
for this view will re-render.
Item Index
Methods
- $
- _applyAttributeBindings
- _applyClassNameBindings
- _classStringForProperty
- _contextDidChange
- _elementDidChange
- _insertElementLater
- _isVisibleDidChange
- _notifyWillDestroyElement
- _parentViewDidChange
- _scheduledDestroy
- addObserver
- append
- appendTo
- beginPropertyChanges
- cacheFor
- createChildView
- createElement
- decrementProperty
- destroy
- destroyElement
- eachComputedProperty
- endPropertyChanges
- findElementInParentElement
- get
- getProperties
- getWithDefault
- handleEvent
- has
- hasObserverFor
- incrementProperty
- init
- invokeRecursively
- metaForProperty
- nearestChildOf
- nearestInstanceOf deprecated
- nearestOfType
- nearestWithProperty
- notifyPropertyChange
- off
- on
- one
- propertyDidChange
- propertyWillChange
- remove
- removeAllChildren
- removeChild
- removeFromParent
- removeObserver
- render
- renderToBuffer
- reopen
- reopenClass
- replaceIn
- rerender
- send
- set
- setProperties
- setUnknownProperty
- toggleProperty
- toString
- trigger
- willDestroy
- willMergeMixin
Properties
- _context
- actions
- ariaRole
- attributeBindings
- childViews
- classNameBindings
- classNames
- concatenatedProperties
- context
- controller
- displayTemplate
- element
- instrumentDisplay
- inverseTemplate
- isDestroyed
- isDestroying
- isVisible
- layout
- layoutName
- parentView
- path
- pathRoot
- preserveContext
- previousContext
- shouldDisplayFunc
- tagName
- template
- templateName
Methods
$
(
JQuery
-
[selector]
Returns a jQuery object for this view's element. If you pass in a selector
string, this method will return a jQuery object, using the current element
as its buffer.
For example, calling
view.$('li') will return a jQuery object containing
all of the li elements inside the DOM element of this view.
Parameters:
-
[selector]String optionala jQuery-compatible selector string
Returns:
JQuery:
the jQuery object for the DOM node
_applyAttributeBindings
(
private
-
buffer
Iterates through the view's attribute bindings, sets up observers for each,
then applies the current value of the attributes to the passed render buffer.
Parameters:
-
bufferEmber.RenderBuffer
_applyClassNameBindings
()
private
Iterates over the view's
classNameBindings array, inserts the value
of the specified property into the classNames array, then creates an
observer to update the view's element if the bound property ever changes
in the future.
_classStringForProperty
(
private
-
property
Given a property name, returns a dasherized version of that
property name if the property evaluates to a non-falsy value.
For example, if the view has property
isUrgent that evaluates to true,
passing isUrgent to this method will return "is-urgent".
Parameters:
-
propertyObject
_contextDidChange
()
private
If a value that affects template rendering changes, the view should be
re-rendered to reflect the new value.
_elementDidChange
()
private
If this view's element changes, we need to invalidate the caches of our
child views so that we do not retain references to DOM elements that are
no longer needed.
_insertElementLater
(
private
-
fn
Schedules a DOM operation to occur during the next render phase. This
ensures that all bindings have finished synchronizing before the view is
rendered.
To use, pass a function that performs a DOM operation.
Before your function is called, this view and all child views will receive
the
willInsertElement event. After your function is invoked, this view
and all of its child views will receive the didInsertElement event.
`javascript
view._insertElementLater(function() {
this.createElement();
this.$().appendTo('body');
});
`
Parameters:
-
fnFunctionthe function that inserts the element into the DOM
_isVisibleDidChange
()
private
When the view's
isVisible property changes, toggle the visibility
element of the actual DOM element.
_notifyWillDestroyElement
()
private
Triggers the
willDestroyElement event (which invokes the
willDestroyElement() method if it exists) on this view and all child
views.
Before triggering willDestroyElement, it first triggers the
willClearRender event recursively.
_parentViewDidChange
()
private
When the parent view changes, recursively invalidate
controller
_scheduledDestroy
()
private
Invoked by the run loop to actually destroy the object. This is
scheduled for execution by the
destroy method.
addObserver
(
-
key -
target -
method
Adds an observer on a property.
This is the core method used to register an observer for a property.
Once you call this method, any time the key's value is set, your observer
will be notified. Note that the observers are triggered any time the
value is set, regardless of whether it has actually changed. Your
observer should be prepared to handle that.
You can also pass an optional context parameter to this method. The
context will be passed to your observer method whenever it is triggered.
Note that if you add the same target/method pair on a key multiple times
with different context parameters, your observer will only be called once
with the last context you passed.
### Observer Methods
Observer methods you pass should generally have the following signature if
you do not pass a
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.
append
()
Ember.View
Appends the view's element to the document body. If the view does
not have an HTML representation yet,
createElement() will be called
automatically.
If your application uses the rootElement property, you must append
the view within that element. Rendering views outside of the rootElement
is not supported.
Note that this method just schedules the view to be appended; the DOM
element will not be appended to the document body until all bindings have
finished synchronizing.
Returns:
Ember.View:
receiver
appendTo
(
Ember.View
-
A
Appends the view's element to the specified parent element.
If the view does not have an HTML representation yet,
createElement()
will be called automatically.
Note that this method just schedules the view to be appended; the DOM
element will not be appended to the given element until all bindings have
finished synchronizing.
This is not typically a function that you will need to call directly when
building your application. You might consider using Ember.ContainerView
instead. If you do need to use appendTo, be sure that the target element
you are providing is associated with an Ember.Application and does not
have an ancestor element that is associated with an Ember view.
Parameters:
-
AString | DOMElement | JQueryselector, element, HTML string, or jQuery object
Returns:
Ember.View:
receiver
beginPropertyChanges
()
Ember.Observable
Begins a grouping of property changes.
You can use this method to group property changes so that notifications
will not be sent until the changes are finished. If you plan to make a
large number of changes to an object at one time, you should call this
method at the beginning of the changes to begin deferring change
notifications. When you are done making changes, call
endPropertyChanges() to deliver the deferred change notifications and end
deferring.
Returns:
cacheFor
(
Object
-
keyName
Returns the cached value of a computed property, if it exists.
This allows you to inspect the value of a computed property
without accidentally invoking it if it is intended to be
generated lazily.
Parameters:
-
keyNameString
Returns:
Object:
The cached value of the computed property, if any
createChildView
(
Ember.View
-
viewClass -
[attrs]
Instantiates a view to be added to the childViews array during view
initialization. You generally will not call this method directly unless
you are overriding
createChildViews(). Note that this method will
automatically configure the correct settings on the new view instance to
act as a child of the parent.
Parameters:
-
viewClassClass | String -
[attrs]Hash optionalAttributes to add
Returns:
Ember.View:
new instance
createElement
()
Ember.View
Creates a DOM representation of the view and all of its
child views by recursively calling the
render() method.
After the element has been created, didInsertElement will
be called on this view and all of its child views.
Returns:
Ember.View:
receiver
decrementProperty
(
Number
-
keyName -
decrement
Set the value of a property to the current value minus some amount.
`javascript
player.decrementProperty('lives');
orc.decrementProperty('health', 5);
`
Parameters:
-
keyNameStringThe name of the property to decrement -
decrementNumberThe amount to decrement by. Defaults to 1
Returns:
Number:
The new property value
destroy
()
You must call
destroy on a view to destroy the view (and all of its
child views). This will remove the view from any parent node, then make
sure that the DOM element managed by the view can be released by the
memory manager.
destroyElement
()
Ember.View
Destroys any existing element along with the element for any child views
as well. If the view does not currently have a element, then this method
will do nothing.
If you implement
willDestroyElement() on your view, then this method will
be invoked on your view before your element is destroyed to give you a
chance to clean up any event handlers, etc.
If you write a willDestroyElement() handler, you can assume that your
didInsertElement() handler was called earlier for the same element.
You should not call or override this method yourself, but you may
want to implement the above callbacks.
Returns:
Ember.View:
receiver
eachComputedProperty
(
-
callback -
binding
Iterate over each computed property for the class, passing its name
and any associated metadata (see
metaForProperty) to the callback.
Parameters:
-
callbackFunction -
bindingObject
endPropertyChanges
()
Ember.Observable
Ends a grouping of property changes.
You can use this method to group property changes so that notifications
will not be sent until the changes are finished. If you plan to make a
large number of changes to an object at one time, you should call
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:
findElementInParentElement
(
DOMElement
-
parentElement
Attempts to discover the element in the parent element. The default
implementation looks for an element with an ID of
elementId (or the
view's guid if elementId is null). You can override this method to
provide your own form of lookup. For example, if you want to discover your
element using a CSS class name instead of an ID.
Parameters:
-
parentElementDOMElementThe parent's DOM element
Returns:
DOMElement:
The discovered element
get
(
Object
-
keyName
Retrieves the value of a property from the object.
This method is usually similar to using
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: function() {
return this.get('firstName') + ' ' + this.get('lastName');
}.property('firstName', '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:
-
keyNameStringThe property to retrieve
Returns:
Object:
The property value or undefined.
getProperties
(
Hash
-
list
To get multiple properties at once, call
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:
-
listString... | Arrayof keys to get
Returns:
Hash:
getWithDefault
(
Object
-
keyName -
defaultValue
Retrieves the value of a property, or a default value in the case that the
property returns
undefined.
`javascript
person.getWithDefault('lastName', 'Doe');
`
Parameters:
-
keyNameStringThe name of the property to retrieve -
defaultValueObjectThe value to return if the property value is undefined
Returns:
Object:
The property value or the defaultValue.
handleEvent
(
private
-
eventName -
evt
Handle events from
Ember.EventDispatcher
Parameters:
-
eventNameString -
evtEvent
has
(
Boolean
-
name
Checks to see if object has any subscriptions for named event.
Parameters:
-
nameStringThe name of the event
Returns:
Boolean:
does the object have a subscription for event
hasObserverFor
(
Boolean
-
key
Returns
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:
-
keyStringKey to check
Returns:
Boolean:
incrementProperty
(
Number
-
keyName -
increment
Set the value of a property to the current value plus some amount.
`javascript
person.incrementProperty('age');
team.incrementProperty('score', 2);
`
Parameters:
-
keyNameStringThe name of the property to increment -
incrementNumberThe amount to increment by. Defaults to 1
Returns:
Number:
The new property value
init
()
private
Setup a view, but do not finish waking it up.
* configure
childViews
* register the view with the global views hash, which is used for event
dispatch
invokeRecursively
(
private
-
fn -
includeSelf
Run this callback on the current view (unless includeSelf is false) and recursively on child views.
Parameters:
-
fnFunction -
includeSelfBooleanIncludes itself if true.
metaForProperty
(
-
key
In some cases, you may want to annotate computed properties with additional
metadata about how they function or what values they operate on. For
example, computed property functions may close over variables that are then
no longer available for introspection.
You can pass a hash of these values to a computed property like this:
`javascript
person: function() {
var personId = this.get('personId');
return App.Person.create({ id: personId });
}.property().meta({ type: App.Person })
`
Once you've done this, you can retrieve the values saved to the computed
property from your class like this:
`javascript
MyClass.metaForProperty('person');
`
This will return the original hash that was passed to meta().
Parameters:
-
keyStringproperty name
nearestChildOf
(
-
klass
Return the nearest ancestor whose parent is an instance of
klass.
Parameters:
-
klassClassSubclass of Ember.View (or Ember.View itself)
Returns:
Ember.View
nearestInstanceOf
(
deprecated
-
klass
Return the nearest ancestor that is an instance of the provided
class.
Parameters:
-
klassClassSubclass of Ember.View (or Ember.View itself)
Returns:
Ember.View
nearestOfType
(
-
klass
Return the nearest ancestor that is an instance of the provided
class or mixin.
Parameters:
-
klassClass,MixinSubclass of Ember.View (or Ember.View itself), or an instance of Ember.Mixin.
Returns:
Ember.View
nearestWithProperty
(
-
property
Return the nearest ancestor that has a given property.
Parameters:
-
propertyStringA property name
Returns:
Ember.View
notifyPropertyChange
(
Ember.Observable
-
keyName
Convenience method to call
propertyWillChange and propertyDidChange in
succession.
Parameters:
-
keyNameStringThe property key to be notified about.
Returns:
off
(
-
name -
target -
method
Cancels subscription for given name, target, and method.
Parameters:
Returns:
this
on
(
-
name -
[target] -
method
Subscribes to a named event with given function.
`javascript
person.on('didLoad', function() {
// fired once the person has loaded
});
`
An optional target can be passed in as the 2nd argument that will
be set as the "this" for the callback. This is a good way to give your
function access to the object triggering the event. When the target
parameter is used the callback becomes the third argument.
Parameters:
Returns:
this
one
(
-
name -
[target] -
method
Subscribes a function to a named event and then cancels the subscription
after the first time the event is triggered. It is good to use
`one` when
you only care about the first time an event has taken place.
This function takes an optional 2nd argument that will become the "this"
value for the callback. If this argument is passed then the 3rd argument
becomes the function.
Parameters:
Returns:
this
propertyDidChange
(
Ember.Observable
-
keyName
Notify the observer system that a property has just changed.
Sometimes you need to change a value directly or indirectly without
actually calling
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:
-
keyNameStringThe property key that has just changed.
Returns:
propertyWillChange
(
Ember.Observable
-
keyName
Notify the observer system that a property is about to change.
Sometimes you need to change a value directly or indirectly without
actually calling
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:
-
keyNameStringThe property key that is about to change.
Returns:
remove
()
Ember.View
Removes the view's element from the element to which it is attached.
Returns:
Ember.View:
receiver
removeAllChildren
()
Ember.View
Removes all children from the
parentView.
Returns:
Ember.View:
receiver
removeChild
(
Ember.View
-
view
Removes the child view from the parent view.
Parameters:
-
viewEmber.View
Returns:
Ember.View:
receiver
removeFromParent
()
Ember.View
Removes the view from its
parentView, if one is found. Otherwise
does nothing.
Returns:
Ember.View:
receiver
removeObserver
(
-
key -
target -
method
Remove an observer you have previously registered on this object. Pass
the same key, target, and method you passed to
addObserver() and your
target will no longer receive notifications.
render
(
-
buffer
Determines which template to invoke, sets up the correct state based on
that logic, then invokes the default Ember.View render implementation.
This method will first look up the path key on pathRoot,
then pass that value to the shouldDisplayFunc function. If that returns
true, the displayTemplate function will be rendered to DOM. Otherwise,
inverseTemplate, if specified, will be rendered.
For example, if this Ember._HandlebarsBoundView represented the {{#with foo}} helper, it would look up the foo property of its context, and
shouldDisplayFunc would always return true. The object found by looking
up foo would be passed to displayTemplate.
Parameters:
-
bufferEmber.RenderBuffer
renderToBuffer
(
private
-
buffer
Invoked by the view system when this view needs to produce an HTML
representation. This method will create a new render buffer, if needed,
then apply any default attributes, such as class names and visibility.
Finally, the
render() method is invoked, which is responsible for
doing the bulk of the rendering.
You should not need to override this method; instead, implement the
template property, or if you need more control, override the render
method.
Parameters:
-
bufferEmber.RenderBufferthe render buffer. If no buffer is passed, a default buffer, using the current view'stagName, will be used.
reopen
()
Augments a constructor's prototype with additional
properties and functions:
`javascript
MyObject = Ember.Object.extend({
name: 'an object'
});
o = MyObject.create();
o.get('name'); // 'an object'
MyObject.reopen({
say: function(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
()
Augments a constructor's own properties and functions:
`javascript
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
App.Person = Ember.Object.extend({
name : "",
sayHello : function(){
alert("Hello. My name is " + this.get('name'));
}
});
App.Person.reopenClass({
species : "Homo sapiens",
createPerson: function(newPersonsName){
return App.Person.create({
name:newPersonsName
});
}
});
var tom = App.Person.create({
name : "Tom Dale"
});
var yehuda = App.Person.createPerson("Yehuda Katz");
tom.sayHello(); // "Hello. My name is Tom Dale"
yehuda.sayHello(); // "Hello. My name is Yehuda Katz"
alert(App.Person.species); // "Homo sapiens"
`
Note that species and createPerson are *not* valid on the tom and yehuda
variables. They are only valid on App.Person.
To add functions and properties to instances of
a constructor by extending the constructor's prototype
see reopen
replaceIn
(
Ember.View
-
target
Replaces the content of the specified parent element with this view's
element. If the view does not have an HTML representation yet,
createElement() will be called automatically.
Note that this method just schedules the view to be appended; the DOM
element will not be appended to the given element until all bindings have
finished synchronizing
Parameters:
-
targetString | DOMElement | JQueryA selector, element, HTML string, or jQuery object
Returns:
Ember.View:
received
rerender
()
Renders the view again. This will work regardless of whether the
view is already in the DOM or not. If the view is in the DOM, the
rendering process will be deferred to give bindings a chance
to synchronize.
If children were added during the rendering process using
appendChild,
rerender will remove them, because they will be added again
if needed by the next render.
In general, if the display of your view changes, you should modify
the DOM element directly instead of manually calling rerender, which can
be slow.
send
(
-
actionName -
context
Triggers a named action on the
ActionHandler. Any parameters
supplied after the actionName string will be passed as arguments
to the action target function.
If the ActionHandler has its target property set, actions may
bubble to the target. Bubbling happens when an actionName can
not be found in the ActionHandler's actions hash or if the
action target function returns true.
Example
`js
App.WelcomeRoute = Ember.Route.extend({
actions: {
playTheme: function() {
this.send('playMusic', 'theme.mp3');
},
playMusic: function(track) {
// ...
}
}
});
`
Parameters:
-
actionNameStringThe action to trigger -
contexta context to send with the action
set
(
Ember.Observable
-
keyName -
value
Sets the provided key or path to the 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.
### Chaining
In addition to property changes, set() returns the value of the object
itself so you can do chaining like this:
`javascript
record.set('firstName', 'Charles').set('lastName', 'Jolley');
`
Parameters:
-
keyNameStringThe property to set -
valueObjectThe value to set ornull.
Returns:
setProperties
(
Ember.Observable
-
hash
Sets a list of properties at once. These properties are set inside
a single
beginPropertyChanges and endPropertyChanges batch, so
observers will be buffered.
`javascript
record.setProperties({ firstName: 'Charles', lastName: 'Jolley' });
`
Parameters:
-
hashHashthe hash of keys and values to set
Returns:
setUnknownProperty
(
private
-
key -
value
We're using setUnknownProperty as a hook to setup attributeBinding observers for
properties that aren't defined on a view at initialization time.
Note: setUnknownProperty will only be called once for each property.
Parameters:
-
keyObject -
valueObject
toggleProperty
(
Object
-
keyName
Set the value of a boolean property to the opposite of it's
current value.
`javascript
starship.toggleProperty('warpDriveEngaged');
`
Parameters:
-
keyNameStringThe name of the property to toggle
Returns:
Object:
The new property value
toString
()
String
Returns a string representation which attempts to provide more information
than Javascript's "
"
toString typically does, in a generic way for all Ember
objects.
`javascript
App.Person = Em.Object.extend()
person = App.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
Student = App.Person.extend()
student = Student.create()
student.toString() //=> "<(subclass of App.Person):ember1025>"
`
If the method toStringExtension is defined, its return value will be
included in the output.
`javascript
App.Teacher = App.Person.extend({
toStringExtension: function() {
return this.get('fullName');
}
});
teacher = App.Teacher.create()
teacher.toString(); //=> "`
Returns:
String:
string representation
trigger
(
private
-
name
Override the default event firing from
Ember.Evented to
also call methods with the given name.
Parameters:
-
nameString
willDestroy
()
Override to implement teardown.
willMergeMixin
()
private
Moves
actions to _actions at extend time. Note that this currently
modifies the mixin themselves, which is technically dubious but
is practically of little consequence. This may change in the future.
Properties
_context
Unknown
private
Private copy of the view's template context. This can be set directly
by Handlebars without triggering the observer that causes the view
to be re-rendered.
The context of a view is looked up as follows:
1. Supplied context (usually by Handlebars)
2. Specified controller
3.
parentView's context (for a child of a ContainerView)
The code in Handlebars that overrides the _context property first
checks to see whether the view has a specified controller. This is
something of a hack and should be revisited.
actions
Hash
The collection of functions, keyed by name, available on this
ActionHandler as action targets.
These functions will be invoked when a matching {{action}} is triggered
from within a template and the application's current route is this route.
Actions can also be invoked from other parts of your application
via ActionHandler#send.
The actions hash will inherit action handlers from
the actions hash defined on extended parent classes
or mixins rather than just replace the entire hash, e.g.:
`js
App.CanDisplayBanner = Ember.Mixin.create({
actions: {
displayBanner: function(msg) {
// ...
}
}
});
App.WelcomeRoute = Ember.Route.extend(App.CanDisplayBanner, {
actions: {
playMusic: function() {
// ...
}
}
});
// WelcomeRoute, when active, will be able to respond
// to both actions, since the actions hash is merged rather
// then replaced when extending mixins / parent classes.
this.send('displayBanner');
this.send('playMusic');
`
Within a Controller, Route, View or Component's action handler,
the value of the this context is the Controller, Route, View or
Component object:
`js
App.SongRoute = Ember.Route.extend({
actions: {
myAction: function() {
this.controllerFor("song");
this.transitionTo("other.route");
...
}
}
});
`
It is also possible to call this._super() from within an
action handler if it overrides a handler defined on a parent
class or mixin:
Take for example the following routes:
`js
App.DebugRoute = Ember.Mixin.create({
actions: {
debugRouteInformation: function() {
console.debug("trololo");
}
}
});
App.AnnoyingDebugRoute = Ember.Route.extend(App.DebugRoute, {
actions: {
debugRouteInformation: function() {
// also call the debugRouteInformation of mixed in App.DebugRoute
this._super();
// show additional annoyance
window.alert(...);
}
}
});
`
## Bubbling
By default, an action will stop bubbling once a handler defined
on the actions hash handles it. To continue bubbling the action,
you must return true from the handler:
`js
App.Router.map(function() {
this.resource("album", function() {
this.route("song");
});
});
App.AlbumRoute = Ember.Route.extend({
actions: {
startPlaying: function() {
}
}
});
App.AlbumSongRoute = Ember.Route.extend({
actions: {
startPlaying: function() {
// ...
if (actionShouldAlsoBeTriggeredOnParentRoute) {
return true;
}
}
}
});
`
Default: null
ariaRole
String
The WAI-ARIA role of the control represented by this view. For example, a
button may have a role of type 'button', or a pane may have a role of
type 'alertdialog'. This property is used by assistive software to help
visually challenged users navigate rich web applications.
The full list of valid WAI-ARIA roles is available at:
[http://www.w3.org/TR/wai-aria/roles#roles_categorization](http://www.w3.org/TR/wai-aria/roles#roles_categorization)
Default: null
attributeBindings
Unknown
A list of properties of the view to apply as attributes. If the property is
a string value, the value of that string will be applied as the attribute.
Array
private
Array
Array
Array
Object
Object
Function
DOMElement
Function
Unknown
Unknown
Boolean
Function
String
Ember.View
String
Object
Boolean
Object
Function
String
Function
String
`javascript
// Applies the type attribute to the element
// with the value "button", like
Ember.View.extend({
attributeBindings: ['type'],
type: 'button'
});
`
If the value of the property is a Boolean, the name of that property is
added as an attribute.
`javascript
// Renders something like
Ember.View.extend({
attributeBindings: ['enabled'],
enabled: true
});
`
childViews
Array
private
Array of child views. You should never edit this array directly.
Instead, use
appendChild and removeFromParent.
Default: []
classNameBindings
Array
A list of properties of the view to apply as class names. If the property
is a string value, the value of that string will be applied as a class
name.
`javascript
// Applies the 'high' class to the view element
Ember.View.extend({
classNameBindings: ['priority']
priority: 'high'
});
`
If the value of the property is a Boolean, the name of that property is
added as a dasherized class name.
`javascript
// Applies the 'is-urgent' class to the view element
Ember.View.extend({
classNameBindings: ['isUrgent']
isUrgent: true
});
`
If you would prefer to use a custom value instead of the dasherized
property name, you can pass a binding like this:
`javascript
// Applies the 'urgent' class to the view element
Ember.View.extend({
classNameBindings: ['isUrgent:urgent']
isUrgent: true
});
`
This list of properties is inherited from the view's superclasses as well.
Default: []
classNames
Array
Standard CSS class names to apply to the view's outer element. This
property automatically inherits any class names defined by the view's
superclasses as well.
Default: ['ember-view']
concatenatedProperties
Array
Defines the properties that will be concatenated from the superclass
(instead of overridden).
By default, when you extend an Ember class a property defined in
the subclass overrides a property with the same name that is defined
in the superclass. However, there are some cases where it is preferable
to build up a property's value by combining the superclass' property
value with the subclass' value. An example of this in use within Ember
is the
classNames property of Ember.View.
Here is some sample code showing the difference between a concatenated
property and a normal one:
`javascript
App.BarView = Ember.View.extend({
someNonConcatenatedProperty: ['bar'],
classNames: ['bar']
});
App.FooBarView = App.BarView.extend({
someNonConcatenatedProperty: ['foo'],
classNames: ['foo'],
});
var fooBarView = App.FooBarView.create();
fooBarView.get('someNonConcatenatedProperty'); // ['foo']
fooBarView.get('classNames'); // ['ember-view', 'bar', 'foo']
`
This behavior extends to object creation as well. Continuing the
above example:
`javascript
var view = App.FooBarView.create({
someNonConcatenatedProperty: ['baz'],
classNames: ['baz']
})
view.get('someNonConcatenatedProperty'); // ['baz']
view.get('classNames'); // ['ember-view', 'bar', 'foo', 'baz']
`
Adding a single property that is not an array will just add it in the array:
`javascript
var view = App.FooBarView.create({
classNames: 'baz'
})
view.get('classNames'); // ['ember-view', 'bar', 'foo', 'baz']
`
Using the concatenatedProperties property, we can tell to Ember that mix
the content of the properties.
In Ember.View the classNameBindings and attributeBindings properties
are also concatenated, in addition to classNames.
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
context
Object
The object from which templates should access properties.
This object will be passed to the template function each time the render
method is called, but it is up to the individual function to decide what
to do with it.
By default, this will be the view's controller.
controller
Object
The controller managing this view. If this property is set, it will be
made available for use by the template.
displayTemplate
Function
The template to render when shouldDisplayFunc evaluates to true.
Default: null
element
DOMElement
Returns the current DOM element for the view.
inverseTemplate
Function
The template to render when shouldDisplayFunc evaluates to false.
Default: null
isDestroyed
Unknown
Destroyed object property flag.
if this property is
true the observers and bindings were already
removed by the effect of calling the destroy() method.
Default: false
isDestroying
Unknown
Destruction scheduled flag. The
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
isVisible
Boolean
If
false, the view will appear hidden in DOM.
Default: null
layout
Function
A view may contain a layout. A layout is a regular template but
supersedes the
template property during rendering. It is the
responsibility of the layout template to retrieve the template
property from the view (or alternatively, call Handlebars.helpers.yield,
{{yield}}) to render it in the correct location.
This is useful for a view that has a shared wrapper, but which delegates
the rendering of the contents of the wrapper to the template property
on a subclass.
layoutName
String
The name of the layout to lookup if no layout is provided.
By default
Ember.View will lookup a template with this name in
Ember.TEMPLATES (a shared global object).
Default: null
parentView
Ember.View
If the view is currently inserted into the DOM of a parent view, this
property will point to the parent of the view.
Default: null
path
String
The path to look up on pathRoot that is passed to
shouldDisplayFunc to determine which template to render.
In addition, if preserveContext is false, the object at this path will
be passed to the template when rendering.
Default: null
pathRoot
Object
The object from which the path will be looked up. Sometimes this is the
same as the previousContext, but in cases where this view has been
generated for paths that start with a keyword such as view or
controller, the path root will be that resolved object.
preserveContext
Boolean
Whether the template rendered by this view gets passed the context object
of its parent template, or gets passed the value of retrieving path
from the pathRoot.
For example, this is true when using the {{#if}} helper, because the
template inside the helper should look up properties relative to the same
object as outside the block. This would be false when used with {{#with foo}} because the template should receive the object found by evaluating
foo.
Default: false
previousContext
Object
If preserveContext is true, this is the object that will be used
to render the template.
shouldDisplayFunc
Function
The function used to determine if the displayTemplate or
inverseTemplate should be rendered. This should be a function that takes
a value and returns a Boolean.
Default: null
tagName
String
Tag name for the view's outer element. The tag name is only used when an
element is first created. If you change the
tagName for an element, you
must destroy and recreate the view element.
By default, the render buffer will use a <div> tag for views.
Default: null
template
Function
The template used to render the view. This should be a function that
accepts an optional context parameter and returns a string of HTML that
will be inserted into the DOM relative to its parent view.
In general, you should set the
templateName property instead of setting
the template yourself.
templateName
String
The name of the template to lookup if no template is provided.
By default
Ember.View will lookup a template with this name in
Ember.TEMPLATES (a shared global object).
Default: null
Events
didInsertElement
Called when the element of the view has been inserted into the DOM
or after the view was re-rendered. Override this function to do any
set up that requires an element in the document body.
parentViewDidChange
Called when the parentView property has changed.
willClearRender
Called when the view is about to rerender, but before anything has
been torn down. This is a good opportunity to tear down any manual
observers you have installed based on the DOM state
willDestroyElement
Called when the element of the view is going to be destroyed. Override
this function to do any teardown that requires an element, like removing
event listeners.
willInsertElement
Called when a view is going to insert an element into the DOM.