DragDrop Class
A simpler and more efficient drag and drop implementation than the one in YUI core. Highly optimized for delegation-based drag targets, remaining responsive and memory-efficient even when managing thousands of draggable nodes.
Constructor
DragDrop
()
Item Index
Methods
- _addAttrs
- _addLazyAttr
- _addOutOfOrder
- _aggregateAttrs
- _attachEvents
- _attrCfgHash
- _baseDestroy
- _baseInit
- _cacheAttrValue
- _cacheBoundingRects
- _cacheScrollRects
- _cloneDefaultValue
- _defAttrChangeFn
- _defDestroyFn
- _defDragEnterFn
- _defDragFn
- _defDragStartFn
- _defInitFn
- _destroyHierarchy
- _detachEvents
- _endDrag
- _endPendingDrag
- _filterAdHocAttrs
- _findDropIntersection
- _findScrollIntersections
- _fireAttrChange
- _fireDrag
- _fireDragEnter
- _fireDragLeave
- _fireDragStart
- _getAbsoluteBoundingRect
- _getAttr
- _getAttrCfg
- _getAttrCfgs
- _getAttrInitVal
- _getAttrs
- _getBoundingRect
- _getClasses
- _getDelta
- _getFullType
- _getInstanceAttrCfgs
- _getStateVal
- _getType
- _getViewportScrollOffsets
- _hasPotentialSubscribers
- _initAttrHost
- _initAttribute
- _initAttrs
- _initBase
- _initHierarchy
- _initHierarchyData
- _isLazyAttr
- _monitor
- _moveDragNode
- _normAttrVals
- _onContainerScroll
- _onDocMove
- _onDocMoveEnd
- _onDraggableMoveStart
- _onNativeDragStart
- _parseType
- _preInitEventCfg
- _preventedDragEnterFn
- _preventedDragStartFn
- _preventTouchCallout
- _protectAttrs deprecated
- _proxyOrDragNode
- _publish
- _publishAndFire
- _reinitialize
- _restoreTouchCallout
- _scroll
- _set
- _setAttr
- _setAttrs
- _setAttrVal
- _setStateVal
- addAttr
- addAttrs
- addTarget
- after
- attrAdded
- before
- bubble
- destroy
- detach
- detachAll
- fire
- get
- getAttrs
- getEvent
- getTargets
- init
- modifyAttr
- on
- once
- onceAfter
- parseType
- publish
- removeAttr
- removeTarget
- reset
- set
- setAttrs
- subscribe deprecated
- sync
- toString
- unsubscribe deprecated
- unsubscribeAll deprecated
Properties
- _allowAdHocAttrs
- classNames
- name deprecated
Attributes
Methods
_addAttrs
-
cfgs -
values -
lazy
Implementation behind the public addAttrs method.
This method is invoked directly by get if it encounters a scenario in which an attribute's valueFn attempts to obtain the value an attribute in the same group of attributes, which has not yet been added (on demand initialization).
Parameters:
-
cfgsObjectAn object with attribute name/configuration pairs.
-
valuesObjectAn object with attribute name/value pairs, defining the initial values to apply. Values defined in the cfgs argument will be over-written by values in this argument unless defined as read only.
-
lazyBooleanWhether or not to delay the intialization of these attributes until the first call to get/set. Individual attributes can over-ride this behavior by defining a lazyAdd configuration property in their configuration. See addAttr.
_addLazyAttr
-
name -
[lazyCfg]
Finishes initializing an attribute which has been lazily added.
_addOutOfOrder
-
name -
cfg
Utility method used by get/set to add attributes encountered out of order when calling addAttrs().
For example, if:
this.addAttrs({
foo: {
setter: function() {
// make sure this bar is available when foo is added
this.get("bar");
}
},
bar: {
value: ...
}
});_aggregateAttrs
-
allAttrs
A helper method, used by _initHierarchyData to aggregate attribute configuration across the instances class hierarchy.
The method will protect the attribute configuration value to protect the statically defined default value in ATTRS if required (if the value is an object literal, array or the attribute configuration has cloneDefaultValue set to shallow or deep).
Parameters:
-
allAttrsArrayAn array of ATTRS definitions across classes in the hierarchy (subclass first, Base last)
Returns:
The aggregate set of ATTRS definitions for the instance
_attachEvents
()
protected
Attaches event handlers.
_attrCfgHash
()
private
Utility method to define the attribute hash used to filter/whitelist property mixes for this class for iteration performance reasons.
_baseDestroy
()
private
Internal destroy implementation for BaseCore
_baseInit
()
private
Internal initialization implementation for BaseCore
_cacheAttrValue
-
e
Attribute change event handler that caches the new value of the attribute in a protected property on this class.
Parameters:
_cacheBoundingRects
()
Object[]
protected
Caches bounding rect information for every node in the container that
matches the dropSelector.
This is used during a drag to compute dropzone intersections with the dragged node, since mouse events can't be used when the dragged node obscures the dropzone.
Returns:
Array of bounding rects.
_cacheScrollRects
()
Object[]
protected
Caches bounding rect information for all scrollable elements.
This is used during a drag to figure out when we need to auto-scroll a node the pointer is being dragged over.
Returns:
Array of bounding rects.
_cloneDefaultValue
-
cfg
This method assumes that the value has already been checked to be an object. Since it's on a critical path, we don't want to re-do the check.
Parameters:
-
cfgObject
_defAttrChangeFn
-
e -
eventFastPath
Default function for attribute change events.
Parameters:
-
eEventFacadeThe event object for attribute change events.
-
eventFastPathBooleanWhether or not we're using this as a fast path in the case of no listeners or not
_defDragFn
()
protected
Default handler for the drag event.
_defInitFn
-
e
Default init event handler
Parameters:
-
eEventFacadeEvent object, with a cfg property which refers to the configuration object passed to the constructor.
_destroyHierarchy
()
private
Destroys the class hierarchy for this instance by invoking the destructor method on the prototype of each class in the hierarchy.
_detachEvents
()
protected
Detaches event handlers.
_endDrag
()
protected
Ends a drag operation, cleans up after it, and fires a dragend event.
_endPendingDrag
()
protected
Ends a pending drag operation and cleans up after the pending state.
This doesn't prevent a drag operation from starting; it just cleans up temporary state that's only necessary when a drag is pending.
_filterAdHocAttrs
-
allAttrs -
userVals
Parameters:
-
allAttrsObjectThe set of all attribute configurations for this instance. Attributes will be removed from this set, if they belong to the filtered class, so that by the time all classes are processed, allCfgs will be empty.
-
userValsObjectThe config object passed in by the user, from which adhoc attrs are to be filtered.
Returns:
The set of adhoc attributes passed in, in the form of an object with attribute name/configuration pairs.
_findDropIntersection
()
HTMLElement | Null
protected
Searches for a cached drop zone bounding rect that intersects with the current pointer position, and returns the intersected element if found.
Returns:
Intersected drop zone element, or null if no
intersection found.
_findScrollIntersections
()
Object[]
protected
Searches for cached scroll zone bounding rects in which the pointer is currently within the scroll margin (the area near an element's border that should cause the element to scroll).
Returns an array of all intersected scroll zones.
Returns:
Array of intersected scroll zones.
_fireAttrChange
-
attrName -
subAttrName -
currVal -
newVal -
opts -
[cfg]
Utility method to help setup the event payload and fire the attribute change event.
Parameters:
-
attrNameStringThe name of the attribute
-
subAttrNameStringThe full path of the property being changed, if this is a sub-attribute value being change. Otherwise null.
-
currValAnyThe current value of the attribute
-
newValAnyThe new value of the attribute
-
optsObjectAny additional event data to mix into the attribute change event's event facade.
-
[cfg]Object optionalThe attribute config stored in State, if already available.
_fireDrag
()
protected
Fires a drag event and, if necessary, a dragover event.
_fireDragEnter
-
dropNode
Fires a dragenter event for the specified dropzone node.
Parameters:
-
dropNodeNodeDropzone node that was entered.
_fireDragLeave
()
protected
Fires a dragleave event.
_fireDragStart
()
protected
Fires a dragstart event, but only if this._dragState.pending is true.
_getAbsoluteBoundingRect
-
el
Returns a bounding rect for el with absolute coordinates corrected for viewport scroll offsets.
The native getBoundingClientRect() returns coordinates for an element's
position relative to the top left of the viewport, so if the viewport has
been scrolled, its coordinates will be different.
This method returns an element's absolute rect, which will be the same regardless of whether the viewport has been scrolled.
Parameters:
-
elHTMLElementHTML element.
Returns:
Absolute bounding rect for el.
_getAttr
-
name
Provides the common implementation for the public get method, allowing Attribute hosts to over-ride either method.
See get for argument details.
Parameters:
-
nameStringThe name of the attribute.
Returns:
The value of the attribute.
_getAttrCfg
-
name
Returns an object with the configuration properties (and value) for the given attribute. If attrName is not provided, returns the configuration properties for all attributes.
Parameters:
-
nameStringOptional. The attribute name. If not provided, the method will return the configuration for all attributes.
Returns:
The configuration properties for the given attribute, or all attributes.
_getAttrCfgs
()
Object
protected
Returns an aggregated set of attribute configurations, by traversing the class hierarchy.
Returns:
The hash of attribute configurations, aggregated across classes in the hierarchy This value is cached the first time the method, or _getClasses, is invoked. Subsequent invocations return the cached value.
_getAttrInitVal
-
attr -
cfg -
initValues
Returns the initial value of the given attribute from either the default configuration provided, or the over-ridden value if it exists in the set of initValues provided and the attribute is not read-only.
Parameters:
Returns:
The initial value of the attribute.
_getAttrs
-
attrs
Implementation behind the public getAttrs method, to get multiple attribute values.
Parameters:
-
attrsArray | booleanOptional. An array of attribute names. If omitted, all attribute values are returned. If set to true, all attributes modified from their initial values are returned.
Returns:
An object with attribute name/value pairs.
_getBoundingRect
-
el
Returns a bounding rect for el, normalizing for older versions of IE that don't provide height and width information in native bounding rects.
Parameters:
-
elHTMLElementHTML element.
Returns:
Bounding rect for el.
_getClasses
()
Function[]
protected
Returns the class hierarchy for this object, with BaseCore being the last class in the array.
Returns:
An array of classes (constructor functions), making up the class hierarchy for this object. This value is cached the first time the method, or _getAttrCfgs, is invoked. Subsequent invocations return the cached value.
_getDelta
()
Number[]
protected
Returns the XY delta between where the pointer was at the start of the current drag operation and where the pointer is now.
Returns:
Array containing the X and Y deltas.
_getFullType
-
type
Returns the fully qualified type, given a short type string. That is, returns "foo:bar" when given "bar" if "foo" is the configured prefix.
NOTE: This method, unlike _getType, does no checking of the value passed in, and is designed to be used with the low level _publish() method, for critical path implementations which need to fast-track publish for performance reasons.
Parameters:
-
typeStringThe short type to prefix
Returns:
The prefixed type, if a prefix is set, otherwise the type passed in
_getInstanceAttrCfgs
-
allCfgs
A helper method used to isolate the attrs config for this instance to pass to addAttrs,
from the static cached ATTRS for the class.
Parameters:
-
allCfgsObjectThe set of all attribute configurations for this instance. Attributes will be removed from this set, if they belong to the filtered class, so that by the time all classes are processed, allCfgs will be empty.
Returns:
The set of attributes to be added for this instance, suitable
for passing through to addAttrs.
_getStateVal
-
name -
[cfg]
Gets the stored value for the attribute, from either the internal state object, or the state proxy if it exits
Parameters:
Returns:
The stored value of the attribute
_getType
()
private
If the instance has a prefix attribute and the event type is not prefixed, the instance prefix is applied to the supplied type.
_getViewportScrollOffsets
()
Number[]
protected
Returns the current X and Y scroll offsets of the viewport.
Returns:
Array containing the X and Y scroll offsets of the viewport.
_hasPotentialSubscribers
-
fullType
Parameters:
-
fullTypeStringThe fully prefixed type name
Returns:
Whether the event has potential subscribers or not
_initAttrHost
-
attrs -
values -
lazy
Constructor logic for attributes. Initializes the host state, and sets up the inital attributes passed to the constructor.
Parameters:
-
attrsObjectThe attributes to add during construction (passed through to addAttrs). These can also be defined on the constructor being augmented with Attribute by defining the ATTRS property on the constructor.
-
valuesObjectThe initial attribute values to apply (passed through to addAttrs). These are not merged/cloned. The caller is responsible for isolating user provided values if required.
-
lazyBooleanWhether or not to add attributes lazily (passed through to addAttrs).
_initAttribute
()
private
Initializes AttributeCore
_initAttrs
-
attrs -
values -
lazy
Utility method to set up initial attributes defined during construction, either through the constructor.ATTRS property, or explicitly passed in.
Parameters:
-
attrsObjectThe attributes to add during construction (passed through to addAttrs). These can also be defined on the constructor being augmented with Attribute by defining the ATTRS property on the constructor.
-
valuesObjectThe initial attribute values to apply (passed through to addAttrs). These are not merged/cloned. The caller is responsible for isolating user provided values if required.
-
lazyBooleanWhether or not to add attributes lazily (passed through to addAttrs).
_initBase
-
config
Internal construction logic for BaseCore.
Parameters:
-
configObjectThe constructor configuration object
_initHierarchy
-
userVals
Initializes the class hierarchy for the instance, which includes initializing attributes for each class defined in the class's static ATTRS property and invoking the initializer method on the prototype of each class in the hierarchy.
Parameters:
-
userValsObjectObject with configuration property name/value pairs
_initHierarchyData
()
private
A helper method used by _getClasses and _getAttrCfgs, which determines both the array of classes and aggregate set of attribute configurations across the class hierarchy for the instance.
_isLazyAttr
-
name
Checks whether or not the attribute is one which has been added lazily and still requires initialization.
Parameters:
-
nameStringThe name of the attribute
Returns:
true if it's a lazily added attribute, false otherwise.
_monitor
-
what -
eventType -
o
This is the entry point for the event monitoring system. You can monitor 'attach', 'detach', 'fire', and 'publish'. When configured, these events generate an event. click -> click_attach, click_detach, click_publish -- these can be subscribed to like other events to monitor the event system. Inividual published events can have monitoring turned on or off (publish can't be turned off before it it published) by setting the events 'monitor' config.
Parameters:
-
whatString'attach', 'detach', 'fire', or 'publish'
-
eventTypeString | CustomEventThe prefixed name of the event being monitored, or the CustomEvent object.
-
oObjectInformation about the event interaction, such as fire() args, subscription category, publish config
_moveDragNode
()
protected
Moves the dragged node or its proxy to the current pointer location, but constrained within the container if the pointer is outside the container.
_normAttrVals
-
valueHash
Utility method to normalize attribute values. The base implementation simply merges the hash to protect the original.
Parameters:
-
valueHashObjectAn object with attribute name/value pairs
Returns:
An object literal with 2 properties - "simple" and "complex", containing simple and complex attribute values respectively keyed by the top level attribute name, or null, if valueHash is falsey.
_onContainerScroll
()
protected
Handles native scroll events on the container if the container isn't the
body. This is necessary in order to update bounding client rects when
scrollable containers are scrolled.
_onDocMoveEnd
()
protected
Handler for the gesturemoveend event.
_onDraggableMoveStart
-
e
Handler for the gesturemovestart event.
Parameters:
_onNativeDragStart
-
e
Handles native dragstart events on draggable nodes.
The default behavior of these events must be prevented in order to avoid conflicts.
Parameters:
_parseType
()
private
Returns an array with the detach key (if provided), and the prefixed event name from _getType Y.on('detachcategory| menu:click', fn)
_preInitEventCfg
-
config
Handles the special on, after and target properties which allow the user to easily configure on and after listeners as well as bubble targets during construction, prior to init.
Parameters:
-
configObjectThe user configuration object
_preventedDragEnterFn
-
e
Called when the dragenter event's default handler is prevented.
This will prevent the entered node from being considered a valid dropzone.
Parameters:
_preventedDragStartFn
()
protected
Called when the dragstart event's default handler is prevented.
This will cancel the drag operation.
_preventTouchCallout
()
protected
Prevents the WebKit long-touch callout menu from appearing on the current dragNode, if any.
_protectAttrs
-
attrs
Utility method to protect an attribute configuration hash, by merging the entire object and the individual attr config objects.
Parameters:
-
attrsObjectA hash of attribute to configuration object pairs.
Returns:
A protected version of the attrs argument.
_proxyOrDragNode
()
Node
protected
Returns the proxy node associated with the current drag operation, or the original dragged node if node proxy node is set.
Returns:
Proxy node or original dragged node.
_publish
-
fullType -
etOpts -
ceOpts
The low level event publish implementation. It expects all the massaging to have been done
outside of this method. e.g. the type to fullType conversion. It's designed to be a fast
path publish, which can be used by critical code paths to improve performance.
Parameters:
Returns:
The published event. If called without etOpts or ceOpts, this will
be the default CustomEvent instance, and can be configured independently.
_publishAndFire
-
name -
facade -
[options]
Utility method for lazily publishing and firing events.
_reinitialize
()
protected
Detaches and reattaches event handlers.
This is necessary after the container, dragSelector, or dropSelector
attributes are changed.
_restoreTouchCallout
()
protected
Restores the original value of the current dragNode's webkitTouchCallout
style before it was prevented by _preventTouchCallout().
_scroll
-
[amount=1]
Begins scrolling all currently intersected scroll zones in whichever direction(s) they need to be scrolled.
Scrolling will continue (and will accelerate in speed) until the
_scrollIntersections property is empty.
Parameters:
-
[amount=1]Number optionalNumber of pixels to scroll. Scrolling will automatically accelerate as long as the pointer remains within a scroll margin.
_set
-
name -
val -
[opts]
Allows setting of readOnly/writeOnce attributes. See set for argument details.
Parameters:
Returns:
A reference to the host object.
_setAttr
-
name -
value -
[opts] -
force
Provides the common implementation for the public set and protected _set methods.
See set for argument details.
Parameters:
Returns:
A reference to the host object.
_setAttrs
-
attrs -
[opts]
Implementation behind the public setAttrs method, to set multiple attribute values.
Parameters:
Returns:
A reference to the host object.
_setAttrVal
-
attrName -
subAttrName -
prevVal -
newVal -
[opts] -
[attrCfg]
Updates the stored value of the attribute in the privately held State object, if validation and setter passes.
Parameters:
-
attrNameStringThe attribute name.
-
subAttrNameStringThe sub-attribute name, if setting a sub-attribute property ("x.y.z").
-
prevValAnyThe currently stored value of the attribute.
-
newValAnyThe value which is going to be stored.
-
[opts]Object optionalOptional data providing the circumstances for the change.
-
[attrCfg]Object optionalOptional config hash for the attribute. This is added for performance along the critical path, where the calling method has already obtained the config from state.
Returns:
true if the new attribute value was stored, false if not.
_setStateVal
-
name -
value
Sets the stored value for the attribute, in either the internal state object, or the state proxy if it exits
Parameters:
-
nameStringThe name of the attribute
-
valueAnyThe value of the attribute
addAttr
-
name -
config -
lazy
Adds an attribute with the provided configuration to the host object.
The config argument object supports the following properties:
- value <Any>
- The initial value to set on the attribute
- valueFn <Function | String>
-
A function, which will return the initial value to set on the attribute. This is useful for cases where the attribute configuration is defined statically, but needs to reference the host instance ("this") to obtain an initial value. If both the value and valueFn properties are defined, the value returned by the valueFn has precedence over the value property, unless it returns undefined, in which case the value property is used.
valueFn can also be set to a string, representing the name of the instance method to be used to retrieve the value.
- readOnly <boolean>
- Whether or not the attribute is read only. Attributes having readOnly set to true cannot be modified by invoking the set method.
- writeOnce <boolean> or <string>
-
Whether or not the attribute is "write once". Attributes having writeOnce set to true,
can only have their values set once, be it through the default configuration,
constructor configuration arguments, or by invoking set.
The writeOnce attribute can also be set to the string "initOnly", in which case the attribute can only be set during initialization (when used with Base, this means it can only be set during construction)
- setter <Function | String>
-
The setter function used to massage or normalize the value passed to the set method for the attribute. The value returned by the setter will be the final stored value. Returning Attribute.INVALID_VALUE, from the setter will prevent the value from being stored.
setter can also be set to a string, representing the name of the instance method to be used as the setter function.
- getter <Function | String>
-
The getter function used to massage or normalize the value returned by the get method for the attribute. The value returned by the getter function is the value which will be returned to the user when they invoke get.
getter can also be set to a string, representing the name of the instance method to be used as the getter function.
- validator <Function | String>
-
The validator function invoked prior to setting the stored value. Returning false from the validator function will prevent the value from being stored.
validator can also be set to a string, representing the name of the instance method to be used as the validator function.
- lazyAdd <boolean>
- Whether or not to delay initialization of the attribute until the first call to get/set it. This flag can be used to over-ride lazy initialization on a per attribute basis, when adding multiple attributes through the addAttrs method.
The setter, getter and validator are invoked with the value and name passed in as the first and second arguments, and with the context ("this") set to the host object.
Configuration properties outside of the list mentioned above are considered private properties used internally by attribute, and are not intended for public use.
Parameters:
-
nameStringThe name of the attribute.
-
configObjectAn object with attribute configuration property/value pairs, specifying the configuration for the attribute.
NOTE: The configuration object is modified when adding an attribute, so if you need to protect the original values, you will need to merge the object.
-
lazyBoolean(optional) Whether or not to add this attribute lazily (on the first call to get/set).
Returns:
A reference to the host object.
addAttrs
-
cfgs -
values -
lazy
Configures a group of attributes, and sets initial values.
NOTE: This method does not isolate the configuration object by merging/cloning. The caller is responsible for merging/cloning the configuration object if required.
Parameters:
-
cfgsObjectAn object with attribute name/configuration pairs.
-
valuesObjectAn object with attribute name/value pairs, defining the initial values to apply. Values defined in the cfgs argument will be over-written by values in this argument unless defined as read only.
-
lazyBooleanWhether or not to delay the intialization of these attributes until the first call to get/set. Individual attributes can over-ride this behavior by defining a lazyAdd configuration property in their configuration. See addAttr.
Returns:
A reference to the host object.
addTarget
-
o
Registers another EventTarget as a bubble target. Bubble order is determined by the order registered. Multiple targets can be specified.
Events can only bubble if emitFacade is true.
Included in the event-custom-complex submodule.
Parameters:
-
oEventTargetthe target to add
after
-
type -
fn -
[context] -
[arg*]
Subscribe to a custom event hosted by this object. The supplied callback will execute after any listeners add via the subscribe method, and after the default function, if configured for the event, has executed.
Parameters:
Returns:
A subscription handle capable of detaching the subscription
attrAdded
-
name
Checks if the given attribute has been added to the host
Parameters:
-
nameStringThe name of the attribute to check.
Returns:
true if an attribute with the given name has been added, false if it hasn't. This method will return true for lazily added attributes.
before
()
Executes the callback before a DOM event, custom event or method. If the first argument is a function, it is assumed the target is a method. For DOM and custom events, this is an alias for Y.on.
For DOM and custom events: type, callback, context, 0-n arguments
For methods: callback, object (method host), methodName, context, 0-n arguments
Returns:
detach handle
bubble
-
evt
Propagate an event. Requires the event-custom-complex module.
Parameters:
-
evtCustomEventthe custom event to propagate
Returns:
the aggregated return value from Event.Custom.fire
destroy
()
BaseCore
chainable
Destroy lifecycle method. Invokes destructors for the class hierarchy.
Returns:
A reference to this object
detach
-
type -
fn -
context
Detach one or more listeners the from the specified event
Parameters:
-
typeString | ObjectEither the handle to the subscriber or the type of event. If the type is not specified, it will attempt to remove the listener from all hosted events.
-
fnFunctionThe subscribed function to unsubscribe, if not supplied, all subscribers will be removed.
-
contextObjectThe custom object passed to subscribe. This is optional, but if supplied will be used to disambiguate multiple listeners that are the same (e.g., you subscribe many object using a function that lives on the prototype)
Returns:
the host
detachAll
-
type
Removes all listeners from the specified event. If the event type is not specified, all listeners from all hosted custom events will be removed.
Parameters:
-
typeStringThe type, or name of the event
fire
-
type -
arguments
Fire a custom event by name. The callback functions will be executed from the context specified when the event was created, and with the following parameters.
The first argument is the event type, and any additional arguments are passed to the listeners as parameters. If the first of these is an object literal, and the event is configured to emit an event facade, that object is mixed into the event facade and the facade is provided in place of the original object.
If the custom event object hasn't been created, then the event hasn't been published and it has no subscribers. For performance sake, we immediate exit in this case. This means the event won't bubble, so if the intention is that a bubble target be notified, the event must be published on this object first.
Parameters:
-
typeString | ObjectThe type of the event, or an object that contains a 'type' property.
-
argumentsObject*an arbitrary set of parameters to pass to the handler. If the first of these is an object literal and the event is configured to emit an event facade, the event facade will replace that parameter after the properties the object literal contains are copied to the event facade.
Returns:
True if the whole lifecycle of the event went through, false if at any point the event propagation was halted.
get
-
name
Returns the current value of the attribute. If the attribute has been configured with a 'getter' function, this method will delegate to the 'getter' to obtain the value of the attribute.
Parameters:
-
nameStringThe name of the attribute. If the value of the attribute is an Object, dot notation can be used to obtain the value of a property of the object (e.g.
get("x.y.z"))
Returns:
The value of the attribute
getAttrs
-
attrs
Gets multiple attribute values.
Parameters:
-
attrsArray | booleanOptional. An array of attribute names. If omitted, all attribute values are returned. If set to true, all attributes modified from their initial values are returned.
Returns:
An object with attribute name/value pairs.
getEvent
-
type -
prefixed
Returns the custom event of the provided type has been created, a falsy value otherwise
Parameters:
Returns:
the custom event or null
getTargets
()
Returns an array of bubble targets for this object.
Returns:
EventTarget[]
init
-
cfg
Init lifecycle method, invoked during construction. Sets up attributes and invokes initializers for the class hierarchy.
Parameters:
-
cfgObjectObject with configuration property name/value pairs
Returns:
A reference to this object
modifyAttr
-
name -
config
Updates the configuration of an attribute which has already been added.
The properties which can be modified through this interface are limited to the following subset of attributes, which can be safely modified after a value has already been set on the attribute: readOnly, writeOnce, broadcast and getter.
on
-
type -
fn -
[context] -
[arg*]
Subscribe a callback function to a custom event fired by this object or from an object that bubbles its events to this object.
Callback functions for events published with emitFacade = true will
receive an EventFacade as the first argument (typically named "e").
These callbacks can then call e.preventDefault() to disable the
behavior published to that event's defaultFn. See the EventFacade
API for all available properties and methods. Subscribers to
non-emitFacade events will receive the arguments passed to fire()
after the event name.
To subscribe to multiple events at once, pass an object as the first argument, where the key:value pairs correspond to the eventName:callback, or pass an array of event names as the first argument to subscribe to all listed events with the same callback.
Returning false from a callback is supported as an alternative to
calling e.preventDefault(); e.stopPropagation();. However, it is
recommended to use the event methods whenever possible.
Parameters:
Returns:
A subscription handle capable of detaching that subscription
once
-
type -
fn -
[context] -
[arg*]
Listen to a custom event hosted by this object one time.
This is the equivalent to on except the
listener is immediatelly detached when it is executed.
Parameters:
Returns:
A subscription handle capable of detaching the subscription
onceAfter
-
type -
fn -
[context] -
[arg*]
Listen to a custom event hosted by this object one time.
This is the equivalent to after except the
listener is immediatelly detached when it is executed.
Parameters:
Returns:
A subscription handle capable of detaching that subscription
parseType
-
type -
[pre=this._yuievt.config.prefix]
Takes the type parameter passed to 'on' and parses out the various pieces that could be included in the type. If the event type is passed without a prefix, it will be expanded to include the prefix one is supplied or the event target is configured with a default prefix.
Returns:
an array containing: the detach category, if supplied, the prefixed event type, whether or not this is an after listener, the supplied event type
publish
-
type -
opts
Creates a new custom event of the specified type. If a custom event by that name already exists, it will not be re-created. In either case the custom event is returned.
Parameters:
-
typeStringthe type, or name of the event
-
optsObjectoptional config params. Valid properties are:
- 'broadcast': whether or not the YUI instance and YUI global are notified when the event is fired (false)
- 'bubbles': whether or not this event bubbles (true) Events can only bubble if emitFacade is true.
- 'context': the default execution context for the listeners (this)
- 'defaultFn': the default function to execute when this event fires if preventDefault was not called
- 'emitFacade': whether or not this event emits a facade (false)
- 'prefix': the prefix for this targets events, e.g., 'menu' in 'menu:click'
- 'fireOnce': if an event is configured to fire once, new subscribers after the fire will be notified immediately.
- 'async': fireOnce event listeners will fire synchronously if the event has already fired unless async is true.
- 'preventable': whether or not preventDefault() has an effect (true)
- 'preventedFn': a function that is executed when preventDefault is called
- 'queuable': whether or not this event can be queued during bubbling (false)
- 'silent': if silent is true, debug messages are not provided for this event.
- 'stoppedFn': a function that is executed when stopPropagation is called
- 'monitored': specifies whether or not this event should send notifications about when the event has been attached, detached, or published.
- 'type': the event type (valid option if not provided as the first parameter to publish)
Returns:
the custom event
removeAttr
-
name
Removes an attribute from the host object
Parameters:
-
nameStringThe name of the attribute to be removed.
reset
-
name
Resets the attribute (or all attributes) to its initial value, as long as the attribute is not readOnly, or writeOnce.
Parameters:
-
nameStringOptional. The name of the attribute to reset. If omitted, all attributes are reset.
Returns:
A reference to the host object.
set
-
name -
value -
[opts]
Sets the value of an attribute.
Parameters:
-
nameStringThe name of the attribute. If the current value of the attribute is an Object, dot notation can be used to set the value of a property within the object (e.g.
set("x.y.z", 5)). -
valueAnyThe value to set the attribute to.
-
[opts]Object optionalOptional data providing the circumstances for the change.
Returns:
A reference to the host object.
setAttrs
-
attrs -
[opts]
Sets multiple attribute values.
Parameters:
Returns:
A reference to the host object.
subscribe
()
deprecated
subscribe to an event
sync
()
chainable
Synchronizes the internal cache of dropzone node locations, which is used to determine whether a dragged node may be dropped.
You should call this method if you modify the DOM or change the position or metrics of a dropzone node during a drag operation. Otherwise, dropzone positions may be miscalculated.
Calling this method when a drag operation is not in progress will have no effect.
toString
()
String
Default toString implementation. Provides the constructor NAME and the instance guid, if set.
Returns:
String representation for this object
unsubscribe
()
deprecated
detach a listener
unsubscribeAll
-
type
Removes all listeners from the specified event. If the event type is not specified, all listeners from all hosted custom events will be removed.
Parameters:
-
typeStringThe type, or name of the event
Properties
_allowAdHocAttrs
Boolean
protected
This property controls whether or not instances of this class should allow users to add ad-hoc attributes through the constructor configuration hash.
AdHoc attributes are attributes which are not defined by the class, and are not handled by the MyClass._NON_ATTRS_CFG
Default: undefined (false)
classNames
Object
CSS class names used by DragDrop.
Sub-properties:
-
draggingObjectClass name applied to a node or proxy node that's being dragged.
-
dragoverObjectClass name applied to a dropzone node over which a draggable node is currently being dragged.
-
droppableObjectClass name applied to a node or proxy node that's currently being dragged and can be dropped.
Attributes
container
HTMLElement | Node | String
Container node to which drag operations should be constrained. All draggable nodes and dropzones must be descendants of this container, and draggable nodes will not be draggable or droppable outside its borders.
If not specified, the <body> element will be used as the container.
Default: 'body'
Fires event containerChange
Fires when the value for the configuration attribute container is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
destroyed
Boolean
readonly
Flag indicating whether or not this object has been through the destroy lifecycle phase.
Default: false
Fires event destroyedChange
Fires when the value for the configuration attribute destroyed is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
distanceThreshold
Number
Distance in pixels that the mouse cursor must move after a mousedown before the movement will be considered the beginning of a drag event.
This value has no effect on touch-based interactions (see
touchCancelDistance).
Default: 10
Fires event distanceThresholdChange
Fires when the value for the configuration attribute distanceThreshold is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
dragHandleSelector
String
CSS selector that matches one or more nodes within a draggable node that should be treated as drag handles for that node.
If a dragHandleSelector is set, nodes matched by dragSelector will
only be draggable by their handles.
Fires event dragHandleSelectorChange
Fires when the value for the configuration attribute dragHandleSelector is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
dragSelector
String
CSS selector that matches one or more nodes within the container that
should be draggable.
Fires event dragSelectorChange
Fires when the value for the configuration attribute dragSelector is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
dropSelector
String
CSS selector that matches one or more nodes within the container that
should be considered drop zones.
Fires event dropSelectorChange
Fires when the value for the configuration attribute dropSelector is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
enableTouchDrag
Boolean
Whether or not to enable dragging in response to touch events. There are currently some edge cases with this, which is why it might make sense to disable it in certain situations.
Default: true
Fires event enableTouchDragChange
Fires when the value for the configuration attribute enableTouchDrag is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
initialized
Boolean
readonly
Flag indicating whether or not this object has been through the init lifecycle phase.
Default: false
Fires event initializedChange
Fires when the value for the configuration attribute initialized is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
pointerOffset
Number[] | String
Array of custom X and Y pixel offset values specifying how the dragged node or proxy node should be positioned relative to the pointer position, or the string "auto" for an automatic offset based on the initial grab point.
You can override the pointer offset specified here on a per-drag basis
by setting a pointerOffset property on the event facade passed to the
"on" phase of the dragstart event.
Default: 'auto'
Fires event pointerOffsetChange
Fires when the value for the configuration attribute pointerOffset is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
scrollContainer
Boolean
Whether or not to automatically scroll the container if necessary when the pointer approaches an edge during a drag operation.
If it's necessary to auto-scroll nodes other than the container, select
those nodes using the scrollSelector attribute.
Fires event scrollContainerChange
Fires when the value for the configuration attribute scrollContainer is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
scrollMargin
Number
Distance in pixels from the edge of a scrollable node at which the pointer will cause the node to begin scrolling during a drag operation.
The smaller this number is, the closer the pointer will have to be to the edge before the node will start to scroll.
Default: 50
Fires event scrollMarginChange
Fires when the value for the configuration attribute scrollMargin is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
scrollSelector
String
CSS selector that matches scrollable nodes within the container that
should be automatically scrolled when the pointer is dragged near the
node's edges.
Fires event scrollSelectorChange
Fires when the value for the configuration attribute scrollSelector is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
timeThreshold
Number
Amount of time in milliseconds that must pass after a mousedown or tap without a corresponding mouseup or release before we'll consider the action the beginning of a drag event.
For mouse-based interactions, exceeding this threshold will cause a
drag event to start even if the distanceThreshold is not met.
This attribute has no effect on touch-based interactions (see
touchDelay).
Default: 800
Fires event timeThresholdChange
Fires when the value for the configuration attribute timeThreshold is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
touchCancelDistance
Number
Maximum distance in pixels from the original touch point that the
pointer may move during the touchDelay time before a pending drag is
canceled.
This helps avoid triggering unintended drag interactions when the user is actually scrolling or performing some other touch gesture.
This attribute has no effect on mouse-based interactions.
Default: 10
Fires event touchCancelDistanceChange
Fires when the value for the configuration attribute touchCancelDistance is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
touchDelay
Number
Delay in milliseconds after an initial touch before a drag interaction begins when using a touch-based input device.
If the touch ends before this delay is over, or if the touch point moves
by more than touchCancelDistance pixels before this delay is over, the
pending drag is canceled.
This attribute has no effect on mouse-based interactions.
Default: 1000
Fires event touchDelayChange
Fires when the value for the configuration attribute touchDelay is
changed. You can listen for the event using the on method if you
wish to be notified before the attribute's value has changed, or
using the after method if you wish to be notified after the
attribute's value has changed.
Parameters:
-
eEventFacadeAn Event Facade object with the following attribute-specific properties added:
Events
destroy
Lifecycle event for the destroy phase, fired prior to destruction. Invoking the preventDefault method on the event object provided to subscribers will prevent destruction from proceeding.
Subscribers to the "after" moment of this event, will be notified after destruction is complete (and as a result cannot prevent destruction).
Event Payload:
-
eEventFacadeEvent object
drag
Fired whenever the pointer moves during a drag operation.
Call the preventDefault() method on this event's facade to prevent the dragged
node (or its proxy) from being moved to the new location, and to prevent drop
zone intersections from being calculated.
Event Payload:
dragend
Fired after a drag operation ends or is canceled.
Event Payload:
-
deltaXYNumber[]Number of pixels the pointer has moved on the X and Y axes since the drag operation began.
-
dragNodeNodeThe node that was dragged.
-
droppedBooleanWhether or not the drag operation resulted in a successful drop.
-
pageXYNumber[]Current X and Y coordinates of the pointer.
-
startXYNumber[]X and Y coordinates of the pointer when the drag operation began.
dragenter
Fired when the pointer enters a drop zone during a drag operation.
To prevent the drop zone from being treated as a valid drop target, call
preventDefault() on this event's facade.
Event Payload:
-
deltaXYNumber[]Number of pixels the pointer has moved on the X and Y axes since the drag operation began.
-
dragNodeNodeThe node being dragged.
-
dropNodeNodeThe node representing the drop zone.
-
pageXYNumber[]Current X and Y coordinates of the pointer.
-
startXYNumber[]X and Y coordinates of the pointer when the drag operation began.
dragleave
Fired after the pointer leaves a drop zone during a drag operation.
Event Payload:
-
deltaXYNumber[]Number of pixels the pointer has moved on the X and Y axes since the drag operation began.
-
dragNodeNodeThe node being dragged.
-
dropNodeNodeThe node representing the drop zone.
-
pageXYNumber[]Current X and Y coordinates of the pointer.
-
startXYNumber[]X and Y coordinates of the pointer when the drag operation began.
dragover
Fired when the pointer moves over a drop zone during a drag operation.
Event Payload:
-
deltaXYNumber[]Number of pixels the pointer has moved on the X and Y axes since the drag operation began.
-
dragNodeNodeThe node being dragged.
-
dropNodeNodeThe node representing the drop zone.
-
pageXYNumber[]Current X and Y coordinates of the pointer.
-
startXYNumber[]X and Y coordinates of the pointer when the drag operation began.
dragstart
Fired when a drag operation begins.
You can override the pointer offset specified in the pointerOffset attribute
by setting a pointerOffset property on the event facade during the "on" phase
of this event. This custom pointer offset will then be used only for the current
drag operation.
To cancel the drag operation, call preventDefault() on this event's facade.
drop
Fired after a draggable node is dropped onto a node marked as a drop zone.
Event Payload:
-
deltaXYNumber[]Number of pixels the pointer has moved on the X and Y axes since the drag operation began.
-
dragNodeNodeThe node being dragged.
-
dropNodeNodeThe node representing the drop zone.
-
pageXYNumber[]Current X and Y coordinates of the pointer.
-
startXYNumber[]X and Y coordinates of the pointer when the drag operation began.
init
Lifecycle event for the init phase, fired prior to initialization. Invoking the preventDefault() method on the event object provided to subscribers will prevent initialization from occuring.
Subscribers to the "after" momemt of this event, will be notified after initialization of the object is complete (and therefore cannot prevent initialization).
Event Payload:
-
eEventFacadeEvent object, with a cfg property which refers to the configuration object passed to the constructor.