Event Class
The event utility provides functions to add and remove event listeners, event cleansing. It also tries to automatically remove listeners it registers during the unload event.
Item Index
Methods
- _applyFilter
- _clean static
- _isValidCollection static
- _load static
- _poll static
- _unload static
- attach static
- compileFilter static
- define static
- defineOutside static
- delegate static
- detach static
- generateId static
- getEvent static
- getListeners static
- nativeAdd static
- nativeRemove static
- notifySub static
- onAvailable static
- onContentReady static
- purgeElement static
- simulate static
- startInterval static
Properties
- _avail static
- _dri static
- _el_events static
- _interval static
- _loadComplete static
- _retryCount static
- _wrappers static
- DOMReady static
- lastError static
- POLL_INTERVAL static
- POLL_RETRYS static
Methods
_applyFilter
-
filter
-
args
-
ce
Walks up the parent axis of an event's target, and tests each element against a supplied filter function. If any Nodes, including the container, satisfy the filter, the delegated callback will be triggered for each.
Hosted as a protected property of the delegate
method (e.g.
Y.delegate._applyFilter
).
Parameters:
-
filter
Functionboolean function to test for inclusion in event notification
-
args
Arraythe arguments that would be passed to subscribers
-
ce
CustomEventthe DOM event wrapper
_clean
-
wrapper
Removes all object references and the DOM proxy subscription for a given event for a DOM node.
Parameters:
-
wrapper
CustomEventCustom event proxy for the DOM subscription
_isValidCollection
-
o
We want to be able to use getElementsByTagName as a collection to attach a group of events to. Unfortunately, different browsers return different types of collections. This function tests to determine if the object is array-like. It will also fail if the object is an array, but is empty.
Parameters:
-
o
Objectthe object to test
Returns:
_load
()
private
static
hook up any deferred listeners
_poll
()
private
static
Polling function that runs before the onload event fires, attempting to attach to DOM Nodes as soon as they are available
_unload
()
private
static
Removes all listeners registered by pe.event. Called automatically during the unload event.
attach
-
type
-
fn
-
el
-
context
-
args
Adds an event listener
Parameters:
-
type
StringThe type of event to append
-
fn
FunctionThe method the event invokes
-
el
String | HTMLElement | Array | NodeListAn id, an element reference, or a collection of ids and/or elements to assign the listener to.
-
context
Objectoptional context object
-
args
Boolean | Object0..n arguments to pass to the callback
Returns:
compileFilter
-
selector
Compiles a selector string into a filter function to identify whether Nodes along the parent axis of an event's target should trigger event notification.
This function is memoized, so previously compiled filter functions are returned if the same selector string is provided.
This function may be useful when defining synthetic events for delegate handling.
Hosted as a property of the delegate
method (e.g. Y.delegate.compileFilter
).
Parameters:
-
selector
Stringthe selector string to base the filtration on
Returns:
define
-
type
-
config
-
force
Defines a new event in the DOM event system. Implementers are responsible for monitoring for a scenario whereby the event is fired. A notifier object is provided to the functions identified below. When the criteria defining the event are met, call notifier.fire( [args] ); to execute event subscribers.
The first parameter is the name of the event. The second parameter is a
configuration object which define the behavior of the event system when the
new event is subscribed to or detached from. The methods that should be
defined in this configuration object are on
,
detach
, delegate
, and detachDelegate
.
You are free to define any other methods or properties needed to define your
event. Be aware, however, that since the object is used to subclass
SyntheticEvent, you should avoid method names used by SyntheticEvent unless
your intention is to override the default behavior.
This is a list of properties and methods that you can or should specify in the configuration object:
on
function (node, subscription, notifier)
The implementation logic for subscription. Any special setup you need to do to create the environment for the event being fired--E.g. native DOM event subscriptions. Store subscription related objects and state on thesubscription
object. When the criteria have been met to fire the synthetic event, callnotifier.fire(e)
. See Notifier'sfire()
method for details about what to pass as parameters.detach
function (node, subscription, notifier)
The implementation logic for cleaning up a detached subscription. E.g. detach any DOM subscriptions added inon
.delegate
function (node, subscription, notifier, filter)
The implementation logic for subscription viaY.delegate
ornode.delegate
. The filter is typically either a selector string or a function. You can useY.delegate.compileFilter(selectorString)
to create a filter function from a selector string if needed. The filter function expects an event object as input and should output either null, a matching Node, or an array of matching Nodes. Otherwise, this acts likeon
DOM event subscriptions. Store subscription related objects and information on thesubscription
object. When the criteria have been met to fire the synthetic event, callnotifier.fire(e)
as noted above.detachDelegate
function (node, subscription, notifier)
The implementation logic for cleaning up a detached delegate subscription. E.g. detach any DOM delegate subscriptions added indelegate
.publishConfig
- (Object) The configuration object that will be used to instantiate
the underlying CustomEvent. See Notifier's
fire
method for details. processArgs
subMatch
-
function (sub, args)
Compares a set of subscription arguments against a Subscription object to determine if they match. The default implementation compares the callback function against the second argument passed toY.on(...)
ornode.detach(...)
etc.
function (argArray, fromDelegate)
Optional method
to extract any additional arguments from the subscription
signature. Using this allows on
or
delegate
signatures like
node.on("hover", overCallback,
outCallback)
.
When processing an atypical argument signature, make sure the
args array is returned to the normal signature before returning
from the function. For example, in the "hover" example
above, the outCallback
needs to be splice
d
out of the array. The expected signature of the args array for
on()
subscriptions is:
[type, callback, target, contextOverride, argN...]
And for delegate()
:
[type, callback, target, filter, contextOverride, argN...]
where target
is the node the event is being
subscribed for. You can see these signatures documented for
Y.on()
and Y.delegate()
respectively.
Whatever gets returned from the function will be stored on the
subscription
object under
subscription._extra
.
Parameters:
Returns:
defineOutside
-
event
-
name
Defines a new outside event to correspond with the given DOM event.
By default, the created synthetic event name will be the name of the event
with "outside" appended (e.g. "click" becomes "clickoutside"). If you want
a different name for the created Event, pass it as a second argument like so:
Y.Event.defineOutside(eventType, "yonderclick")
.
delegate
-
type
-
fn
-
el
-
filter
-
context
-
args
Sets up event delegation on a container element. The delegated event will use a supplied selector or filtering function to test if the event references at least one node that should trigger the subscription callback.
Selector string filters will trigger the callback if the event originated from a node that matches it or is contained in a node that matches it. Function filters are called for each Node up the parent axis to the subscribing container node, and receive at each level the Node and the event object. The function should return true (or a truthy value) if that Node should trigger the subscription callback. Note, it is possible for filters to match multiple Nodes for a single event. In this case, the delegate callback will be executed for each matching Node.
For each matching Node, the callback will be executed with its 'this'
object set to the Node matched by the filter (unless a specific context was
provided during subscription), and the provided event's
currentTarget
will also be set to the matching Node. The
containing Node from which the subscription was originally made can be
referenced as e.container
.
Parameters:
-
type
Stringthe event type to delegate
-
fn
Functionthe callback function to execute. This function will be provided the event object for the delegated event.
-
el
String | Nodethe element that is the delegation container
-
filter
String | Functiona selector that must match the target of the event or a function to test target and its parents for a match
-
context
Objectoptional argument that specifies what 'this' refers to.
-
args
Object multiple0..n additional arguments to pass on to the callback function. These arguments will be added after the event object.
Returns:
detach
-
type
-
fn
-
el
Removes an event listener. Supports the signature the event was bound with, but the preferred way to remove listeners is using the handle that is returned when using Y.on
Parameters:
-
type
Stringthe type of event to remove.
-
fn
Functionthe method the event invokes. If fn is undefined, then all event handlers for the type of event are removed.
-
el
String | HTMLElement | Array | NodeList | EventHandleAn event handle, an id, an element reference, or a collection of ids and/or elements to remove the listener from.
Returns:
generateId
-
el
Generates an unique ID for the element if it does not already have one.
Parameters:
-
el
Objectthe element to create the id for
Returns:
getEvent
-
e
-
el
Finds the event in the window object, the caller's arguments, or in the arguments of another method in the callstack. This is executed automatically for events registered through the event manager, so the implementer should not normally need to execute this function at all.
Parameters:
-
e
Eventthe event parameter from the handler
-
el
HTMLElementthe element the listener was attached to
Returns:
getListeners
-
el
-
type
Returns all listeners attached to the given element via addListener. Optionally, you can specify a specific type of event to return.
Parameters:
-
el
HTMLElement | Stringthe element or element id to inspect
-
type
Stringoptional type of listener to return. If left out, all listeners will be returned
Returns:
nativeAdd
-
el
-
type
-
fn
-
capture
Adds a DOM event directly without the caching, cleanup, context adj, etc
Parameters:
-
el
HTMLElementthe element to bind the handler to
-
type
Stringthe type of event handler
-
fn
Functionthe callback to invoke
-
capture
Boolencapture or bubble phase
nativeRemove
-
el
-
type
-
fn
-
capture
Basic remove listener
Parameters:
-
el
HTMLElementthe element to bind the handler to
-
type
Stringthe type of event handler
-
fn
Functionthe callback to invoke
-
capture
Boolencapture or bubble phase
notifySub
-
thisObj
-
args
-
ce
Overrides the _notify
method on the normal DOM subscription to
inject the filtering logic and only proceed in the case of a match.
This method is hosted as a private property of the delegate
method
(e.g. Y.delegate.notifySub
)
Parameters:
-
thisObj
Objectdefault 'this' object for the callback
-
args
Arrayarguments passed to the event's
fire()
-
ce
CustomEventthe custom event managing the DOM subscriptions for the subscribed event on the subscribing node.
Returns:
onAvailable
-
id
-
fn
-
p_obj
-
p_override
-
checkContent
Executes the supplied callback when the item with the supplied id is found. This is meant to be used to execute behavior as soon as possible as the page loads. If you use this after the initial page load it will poll for a fixed time for the element. The number of times it will poll and the frequency are configurable. By default it will poll for 10 seconds.
The callback is executed with a single parameter: the custom object parameter, if provided.
Parameters:
-
id
String | | String[]the id of the element, or an array of ids to look for.
-
fn
Functionwhat to execute when the element is found.
-
p_obj
Objectan optional object to be passed back as a parameter to fn.
-
p_override
Boolean | ObjectIf set to true, fn will execute in the context of p_obj, if set to an object it will execute in the context of that object
-
checkContent
Booleancheck child node readiness (onContentReady)
onContentReady
-
id
-
fn
-
obj
-
override
Works the same way as onAvailable, but additionally checks the state of sibling elements to determine if the content of the available element is safe to modify.
The callback is executed with a single parameter: the custom object parameter, if provided.
Parameters:
-
id
Stringthe id of the element to look for.
-
fn
Functionwhat to execute when the element is ready.
-
obj
Objectan optional object to be passed back as a parameter to fn.
-
override
Boolean | ObjectIf set to true, fn will execute in the context of p_obj. If an object, fn will exectute in the context of that object
purgeElement
-
el
-
recurse
-
type
Removes all listeners attached to the given element via addListener. Optionally, the node's children can also be purged. Optionally, you can specify a specific type of event to remove.
Parameters:
-
el
HTMLElementthe element to purge
-
recurse
Booleanrecursively purge this element's children as well. Use with caution.
-
type
Stringoptional type of listener to purge. If left out, all listeners will be removed
simulate
-
target
-
type
-
options
Simulates the event with the given name on a target.
Parameters:
-
target
HTMLElementThe DOM element that's the target of the event.
-
type
StringThe type of event to simulate (i.e., "click").
-
options
Object(Optional) Extra options to copy onto the event object.
Returns:
startInterval
()
private
static
Properties
_avail
Unknown
private
static
onAvailable listeners
_dri
Unknown
private
static
document readystate poll handle
_el_events
Unknown
private
static
Custom event wrapper map DOM events. Key is Element uid stamp. Each item is a hash of custom event wrappers as provided in the _wrappers collection. This provides the infrastructure for getListeners.
_interval
Unknown
private
static
poll handle
_retryCount
Unknown
private
static
The number of times to poll after window.onload. This number is increased if additional late-bound handlers are requested after the page load.
_wrappers
Y.Event.Custom
private
static
Custom event wrappers for DOM events. Key is 'event:' + Element uid stamp + event type
lastError
Error
static
addListener/removeListener can throw errors in unexpected scenarios. These errors are suppressed, the method returns false, and this property is set
POLL_INTERVAL
Int
final
static
The poll interval in milliseconds
POLL_RETRYS
Int
final
static
The number of times we should look for elements that are not in the DOM at the time the event is requested after the document has been loaded. The default is 1000@amp;40 ms, so it will poll for 40 seconds or until all outstanding handlers are bound (whichever comes first).