#

API Docs for: 3.10.3
Show: Inherited Protected Private Deprecated

# ImgLoadGroup Class

Extends Base
Defined in: `imageloader/js/imageloader.js:9`
Module: imageloader

A group for images. A group can have one time limit and a series of triggers. Thus the images belonging to this group must share these constraints.

## Constructor

### `ImgLoadGroup`

()

Defined in `imageloader/js/imageloader.js:9`

- Index
- Methods
- Properties
- Attributes
- Events

## Item Index

### Methods

- _addAttrs
- _addLazyAttr
- _aggregateAttrs
- _attrCfgHash
- _baseDestroy
- _baseInit
- _clearTriggers
- _cloneDefaultValue
- _defAttrChangeFn
- _defDestroyFn
- _defInitFn
- _destroyHierarchy
- _fetchByClass
- _filterAdHocAttrs
- _filterAttrCfgs
- _fireAttrChange
- _foldCheck
- _getAttr
- _getAttrCfg
- _getAttrCfgs
- _getAttrInitVal
- _getAttrs
- _getClasses
- _getFetchTimeout
- _getFullType
- _getStateVal
- _getType
- _init
- _initAttrHost
- _initAttribute
- _initAttrs
- _initBase
- _initHierarchy
- _initHierarchyData
- _isLazyAttr
- _monitor
- _normAttrVals
- _onloadTasks
- _parseType
- _preInitEventCfg
- _protectAttrs deprecated
- _publish
- _set
- _setAttr
- _setAttrs
- _setAttrVal
- _setFoldTriggers
- _setStateVal
- _updateNodeClassName
- addAttr
- addAttrs
- addCustomTrigger
- addTarget
- addTrigger
- after
- attrAdded
- before
- bubble
- destroy
- detach
- detachAll
- fetch
- fire
- get
- getAttrs
- getEvent
- getTargets
- init
- modifyAttr
- on
- once
- onceAfter
- parseType
- publish
- registerImage
- removeAttr
- removeTarget
- reset
- set
- setAttrs
- subscribe deprecated
- toString
- unsubscribe deprecated
- unsubscribeAll deprecated

### Properties

- _allowAdHocAttrs
- _areFoldTriggersSet
- _classImageEls
- _className
- _imgObjs
- _maxKnownHLimit
- _timeout
- _triggers
- name deprecated

### Attributes

- className
- classNameAction
- destroyed
- foldDistance
- initialized
- name
- timeLimit

### Events

- destroy
- init

## Methods

### `_addAttrs`

(

- `cfgs`
- `values`
- `lazy`

)
private

Inherited from AttributeCore: `attribute/js/AttributeCore.js:836`

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:

- `cfgs` Object

  An object with attribute name/configuration pairs.

- `values` Object

  An 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.

- `lazy` Boolean

  Whether 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]`

)
private

Inherited from AttributeCore: `attribute/js/AttributeCore.js:382`

Finishes initializing an attribute which has been lazily added.

#### Parameters:

- `name` Object

  The name of the attribute

- `[lazyCfg]` Object optional

  Optional config hash for the attribute. This is added for performance along the critical path, where the calling method has already obtained lazy config from state.

### `_aggregateAttrs`

(

- `allAttrs`

)
Object private

Inherited from BaseCore: `base/js/BaseCore.js:575`

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:

- `allAttrs` Array

  An array of ATTRS definitions across classes in the hierarchy (subclass first, Base last)

#### Returns:

Object: The aggregate set of ATTRS definitions for the instance

### `_attrCfgHash`

() private

Inherited from BaseCore: `base/js/BaseCore.js:538`

Utility method to define the attribute hash used to filter/whitelist property mixes for this class for iteration performance reasons.

### `_baseDestroy`

() private

Inherited from BaseCore: `base/js/BaseCore.js:309`

Internal destroy implementation for BaseCore

### `_baseInit`

() private

Inherited from BaseCore: `base/js/BaseCore.js:281`

Internal initialization implementation for BaseCore

### `_clearTriggers`

() private

Defined in `imageloader/js/imageloader.js:297`

Clears the timeout and all triggers associated with the group.

### `_cloneDefaultValue`

(

- `cfg`

)
private

Inherited from BaseCore: `base/js/BaseCore.js:549`

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:

- `cfg` Object

### `_defAttrChangeFn`

(

- `e`

)
private

Inherited from AttributeObservable: `attribute/js/AttributeObservable.js:186`

Default function for attribute change events.

#### Parameters:

- `e` EventFacade

  The event object for attribute change events.

### `_defDestroyFn`

(

- `e`

)
protected

Inherited from BaseObservable: `base/js/BaseObservable.js:190`

Default destroy event handler

#### Parameters:

- `e` EventFacade

  Event object

### `_defInitFn`

(

- `e`

)
protected

Inherited from BaseObservable: `base/js/BaseObservable.js:178`

Default init event handler

#### Parameters:

- `e` EventFacade

  Event object, with a cfg property which refers to the configuration object passed to the constructor.

### `_destroyHierarchy`

() private

Inherited from BaseCore: `base/js/BaseCore.js:721`

Destroys the class hierarchy for this instance by invoking the destructor method on the prototype of each class in the hierarchy.

### `_fetchByClass`

() private

Defined in `imageloader/js/imageloader.js:394`

Finds all elements in the DOM with the class name specified in the group. Removes the class from the element in order to let the style definitions trigger the image fetching.

### `_filterAdHocAttrs`

(

- `allAttrs`
- `userVals`

)
Object private

Inherited from BaseCore: `base/js/BaseCore.js:427`

#### Parameters:

- `allAttrs` Object

  The 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.

- `userVals` Object

  The config object passed in by the user, from which adhoc attrs are to be filtered.

#### Returns:

Object: The set of adhoc attributes passed in, in the form of an object with attribute name/configuration pairs.

### `_filterAttrCfgs`

(

- `clazz`
- `allCfgs`

)
Object private

Inherited from BaseCore: `base/js/BaseCore.js:356`

A helper method used when processing ATTRS across the class hierarchy during initialization. Returns a disposable object with the attributes defined for the provided class, extracted from the set of all attributes passed in.

#### Parameters:

- `clazz` Function

  The class for which the desired attributes are required.

- `allCfgs` Object

  The 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:

Object: The set of attributes belonging to the class passed in, in the form of an object with attribute name/configuration pairs.

### `_fireAttrChange`

(

- `attrName`
- `subAttrName`
- `currVal`
- `newVal`
- `opts`
- `[cfg]`

)
private

Inherited from AttributeObservable: `attribute/js/AttributeObservable.js:120`

Utility method to help setup the event payload and fire the attribute change event.

#### Parameters:

- `attrName` String

  The name of the attribute

- `subAttrName` String

  The full path of the property being changed, if this is a sub-attribute value being change. Otherwise null.

- `currVal` Any

  The current value of the attribute

- `newVal` Any

  The new value of the attribute

- `opts` Object

  Any additional event data to mix into the attribute change event's event facade.

- `[cfg]` Object optional

  The attribute config stored in State, if already available.

### `_foldCheck`

() private

Defined in `imageloader/js/imageloader.js:310`

Checks the position of each image in the group. If any part of the image is within the specified distance (`foldDistance`) of the client viewport, the image is fetched immediately.

### `_getAttr`

(

- `name`

)
Any protected chainable

Inherited from AttributeCore: `attribute/js/AttributeCore.js:543`

Provides the common implementation for the public get method, allowing Attribute hosts to over-ride either method.

See get for argument details.

#### Parameters:

- `name` String

  The name of the attribute.

#### Returns:

Any: The value of the attribute.

### `_getAttrCfg`

(

- `name`

)
Object protected

Inherited from AttributeExtras: `attribute/js/AttributeExtras.js:114`

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:

- `name` String

  Optional. The attribute name. If not provided, the method will return the configuration for all attributes.

#### Returns:

Object: The configuration properties for the given attribute, or all attributes.

### `_getAttrCfgs`

() Object protected

Inherited from BaseCore: `base/js/BaseCore.js:339`

Returns an aggregated set of attribute configurations, by traversing the class hierarchy.

#### Returns:

Object: 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`

)
Any private

Inherited from AttributeCore: `attribute/js/AttributeCore.js:945`

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:

- `attr` String

  The name of the attribute

- `cfg` Object

  The attribute configuration object

- `initValues` Object

  The object with simple and complex attribute name/value pairs returned from _normAttrVals

#### Returns:

Any: The initial value of the attribute.

### `_getAttrs`

(

- `attrs`

)
Object protected

Inherited from AttributeCore: `attribute/js/AttributeCore.js:774`

Implementation behind the public getAttrs method, to get multiple attribute values.

#### Parameters:

- `attrs` Array | boolean

  Optional. 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:

Object: An object with attribute name/value pairs.

### `_getClasses`

() Function[] protected

Inherited from BaseCore: `base/js/BaseCore.js:323`

Returns the class hierarchy for this object, with BaseCore being the last class in the array.

#### Returns:

Function[]: 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.

### `_getFetchTimeout`

() Function private

Defined in `imageloader/js/imageloader.js:245`

Returns the group's `fetch` method, with the proper closure, for use with `setTimeout`.

#### Returns:

Function: group's `fetch` method

### `_getFullType`

(

- `type`

)
String private

Inherited from EventTarget: `event-custom/js/event-target.js:586`

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:

- `type` String

  The short type to prefix

#### Returns:

String: The prefixed type, if a prefix is set, otherwise the type passed in

### `_getStateVal`

(

- `name`
- `[cfg]`

)
Any private

Inherited from AttributeCore: `attribute/js/AttributeCore.js:600`

Gets the stored value for the attribute, from either the internal state object, or the state proxy if it exits

#### Parameters:

- `name` String

  The name of the attribute

- `[cfg]` Object optional

  Optional 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:

Any: The stored value of the attribute

### `_getType`

() private

Inherited from EventTarget: `event-custom/js/event-target.js:36`

If the instance has a prefix attribute and the event type is not prefixed, the instance prefix is applied to the supplied type.

### `_init`

() private

Defined in `imageloader/js/imageloader.js:82`

Initialize all private members needed for the group.

### `_initAttrHost`

(

- `attrs`
- `values`
- `lazy`

)
private

Inherited from AttributeCore: `attribute/js/AttributeCore.js:140`

Constructor logic for attributes. Initializes the host state, and sets up the inital attributes passed to the constructor.

#### Parameters:

- `attrs` Object

  The 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.

- `values` Object

  The 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.

- `lazy` Boolean

  Whether or not to add attributes lazily (passed through to addAttrs).

### `_initAttribute`

() private

Inherited from BaseObservable but overwritten in `base/js/BaseCore.js:254`

Initializes AttributeCore

### `_initAttrs`

(

- `attrs`
- `values`
- `lazy`

)
protected

Inherited from AttributeCore: `attribute/js/AttributeCore.js:1011`

Utility method to set up initial attributes defined during construction, either through the constructor.ATTRS property, or explicitly passed in.

#### Parameters:

- `attrs` Object

  The 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.

- `values` Object

  The 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.

- `lazy` Boolean

  Whether or not to add attributes lazily (passed through to addAttrs).

### `_initBase`

(

- `config`

)
private

Inherited from BaseCore: `base/js/BaseCore.js:219`

Internal construction logic for BaseCore.

#### Parameters:

- `config` Object

  The constructor configuration object

### `_initHierarchy`

(

- `userVals`

)
private

Inherited from BaseCore: `base/js/BaseCore.js:659`

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:

- `userVals` Object

  Object with configuration property name/value pairs

### `_initHierarchyData`

() private

Inherited from BaseCore: `base/js/BaseCore.js:457`

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`

)
Boolean private

Inherited from AttributeCore: `attribute/js/AttributeCore.js:369`

Checks whether or not the attribute is one which has been added lazily and still requires initialization.

#### Parameters:

- `name` String

  The name of the attribute

#### Returns:

Boolean: true if it's a lazily added attribute, false otherwise.

### `_monitor`

(

- `what`
- `eventType`
- `o`

)
private

Inherited from EventTarget: `event-custom/js/event-target.js:658`

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 -> clickattach, clickdetach, 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:

- `what` String

  'attach', 'detach', 'fire', or 'publish'

- `eventType` String | CustomEvent

  The prefixed name of the event being monitored, or the CustomEvent object.

- `o` Object

  Information about the event interaction, such as fire() args, subscription category, publish config

### `_normAttrVals`

(

- `valueHash`

)
Object private

Inherited from AttributeCore: `attribute/js/AttributeCore.js:897`

Utility method to normalize attribute values. The base implementation simply merges the hash to protect the original.

#### Parameters:

- `valueHash` Object

  An object with attribute name/value pairs

#### Returns:

Object: 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.

### `_onloadTasks`

() private

Defined in `imageloader/js/imageloader.js:227`

Performs necessary setup at domready time. Initiates time limit for group; executes the fold check for the images.

### `_parseType`

() private

Inherited from EventTarget: `event-custom/js/event-target.js:52`

Returns an array with the detach key (if provided), and the prefixed event name from _getType Y.on('detachcategory| menu:click', fn)

### `_preInitEventCfg`

(

- `config`

)
private

Inherited from BaseObservable: `base/js/BaseObservable.js:98`

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:

- `config` Object

  The user configuration object

### `_protectAttrs`

(

- `attrs`

)
Object deprecated protected

Inherited from AttributeCore: `attribute/js/AttributeCore.js:883`

Deprecated: Use `AttributeCore.protectAttrs()` or `Attribute.protectAttrs()` which are the same static utility method.

Utility method to protect an attribute configuration hash, by merging the entire object and the individual attr config objects.

#### Parameters:

- `attrs` Object

  A hash of attribute to configuration object pairs.

#### Returns:

Object: A protected version of the attrs argument.

### `_publish`

(

- `fullType`
- `etOpts`
- `ceOpts`

)
CustomEvent private

Inherited from EventTarget: `event-custom/js/event-target.js:610`

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:

- `fullType` String

  The prefixed type of the event to publish.

- `etOpts` Object

  The EventTarget specific configuration to mix into the published event.

- `ceOpts` Object

  The publish specific configuration to mix into the published event.

#### Returns:

CustomEvent: The published event. If called without `etOpts` or `ceOpts`, this will be the default `CustomEvent` instance, and can be configured independently.

### `_set`

(

- `name`
- `val`
- `[opts]`

)
Object protected chainable

Inherited from AttributeObservable but overwritten in `attribute/js/AttributeCore.js:427`

Allows setting of readOnly/writeOnce attributes. See set for argument details.

#### Parameters:

- `name` String

  The name of the attribute.

- `val` Any

  The value to set the attribute to.

- `[opts]` Object optional

  Optional data providing the circumstances for the change.

#### Returns:

Object: A reference to the host object.

### `_setAttr`

(

- `name`
- `value`
- `[opts]`
- `force`

)
Object protected chainable

Inherited from AttributeCore: `attribute/js/AttributeCore.js:443`

Provides the common implementation for the public set and protected _set methods.

See set for argument details.

#### Parameters:

- `name` String

  The name of the attribute.

- `value` Any

  The value to set the attribute to.

- `[opts]` Object optional

  Optional data providing the circumstances for the change.

- `force` Boolean

  If true, allows the caller to set values for readOnly or writeOnce attributes which have already been set.

#### Returns:

Object: A reference to the host object.

### `_setAttrs`

(

- `attrs`
- `[opts]`

)
Object protected chainable

Inherited from AttributeObservable but overwritten in `attribute/js/AttributeCore.js:742`

Implementation behind the public setAttrs method, to set multiple attribute values.

#### Parameters:

- `attrs` Object

  An object with attributes name/value pairs.

- `[opts]` Object optional

  Optional data providing the circumstances for the change

#### Returns:

Object: A reference to the host object.

### `_setAttrVal`

(

- `attrName`
- `subAttrName`
- `prevVal`
- `newVal`
- `[opts]`
- `[attrCfg]`

)
Booolean private

Inherited from AttributeCore: `attribute/js/AttributeCore.js:640`

Updates the stored value of the attribute in the privately held State object, if validation and setter passes.

#### Parameters:

- `attrName` String

  The attribute name.

- `subAttrName` String

  The sub-attribute name, if setting a sub-attribute property ("x.y.z").

- `prevVal` Any

  The currently stored value of the attribute.

- `newVal` Any

  The value which is going to be stored.

- `[opts]` Object optional

  Optional data providing the circumstances for the change.

- `[attrCfg]` Object optional

  Optional 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:

Booolean: true if the new attribute value was stored, false if not.

### `_setFoldTriggers`

() private

Defined in `imageloader/js/imageloader.js:207`

Sets the window scroll and window resize triggers for any group that is fold-conditional (i.e., has a fold distance set).

### `_setStateVal`

(

- `name`
- `value`

)
private

Inherited from AttributeCore: `attribute/js/AttributeCore.js:622`

Sets the stored value for the attribute, in either the internal state object, or the state proxy if it exits

#### Parameters:

- `name` String

  The name of the attribute

- `value` Any

  The value of the attribute

### `_updateNodeClassName`

(

- `node`

)
private

Defined in `imageloader/js/imageloader.js:368`

Updates a given node, removing the ImageLoader class name. If the node is an img and the classNameAction is "enhanced", then node class name is removed and also the src attribute is set to the image URL as well as clearing the style background image.

#### Parameters:

- `node` Node

  The node to act on.

### `addAttr`

(

- `name`
- `config`
- `lazy`

)
Object chainable

Inherited from AttributeCore: `attribute/js/AttributeCore.js:157`

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:

- `name` String

  The name of the attribute.

- `config` Object

  An 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.

- `lazy` Boolean

  (optional) Whether or not to add this attribute lazily (on the first call to get/set).

#### Returns:

Object: A reference to the host object.

### `addAttrs`

(

- `cfgs`
- `values`
- `lazy`

)
Object chainable

Inherited from AttributeCore: `attribute/js/AttributeCore.js:805`

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:

- `cfgs` Object

  An object with attribute name/configuration pairs.

- `values` Object

  An 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.

- `lazy` Boolean

  Whether 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:

Object: A reference to the host object.

### `addCustomTrigger`

(

- `name`
- `obj`

)
chainable

Defined in `imageloader/js/imageloader.js:179`

Adds a custom event trigger to the group.

#### Parameters:

- `name` String

  The name of the event

- `obj` Object

  The object on which to attach the event. `obj` is optional - by default the event is attached to the `Y` instance

### `addTarget`

(

- `o`

)

Inherited from EventTarget: `event-custom/js/event-facade.js:455`

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:

- `o` EventTarget

  the target to add

### `addTrigger`

(

- `obj`
- `type`

)
chainable

Defined in `imageloader/js/imageloader.js:152`

Adds a trigger to the group. Arguments are passed to `Y.on`.

#### Parameters:

- `obj` Object

  The DOM object to attach the trigger event to

- `type` String

  The event type

### `after`

(

- `type`
- `fn`
- `[context]`
- `[arg*]`

)
EventHandle

Inherited from EventTarget: `event-custom/js/event-target.js:833`

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:

- `type` String

  The name of the event

- `fn` Function

  The callback to execute in response to the event

- `[context]` Object optional

  Override `this` object in callback

- `[arg*]` Any optional

  0..n additional arguments to supply to the subscriber

#### Returns:

EventHandle: A subscription handle capable of detaching the subscription

### `attrAdded`

(

- `name`

)
Boolean

Inherited from AttributeCore: `attribute/js/AttributeCore.js:341`

Checks if the given attribute has been added to the host

#### Parameters:

- `name` String

  The name of the attribute to check.

#### Returns:

Boolean: 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`

()

Inherited from EventTarget: `event-custom/js/event-target.js:870`

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`

)
Boolean

Inherited from EventTarget: `event-custom/js/event-facade.js:507`

Propagate an event. Requires the event-custom-complex module.

#### Parameters:

- `evt` CustomEvent

  the custom event to propagate

#### Returns:

Boolean: the aggregated return value from Event.Custom.fire

### `destroy`

() BaseCore chainable

Inherited from BaseObservable but overwritten in `base/js/BaseCore.js:297`

Destroy lifecycle method. Invokes destructors for the class hierarchy.

#### Returns:

BaseCore: A reference to this object

### `detach`

(

- `type`
- `fn`
- `context`

)
EventTarget

Inherited from EventTarget: `event-custom/js/event-target.js:346`

Detach one or more listeners the from the specified event

#### Parameters:

- `type` String | Object

  Either 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.

- `fn` Function

  The subscribed function to unsubscribe, if not supplied, all subscribers will be removed.

- `context` Object

  The 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:

EventTarget: the host

### `detachAll`

(

- `type`

)

Inherited from EventTarget: `event-custom/js/event-target.js:469`

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:

- `type` String

  The type, or name of the event

### `fetch`

()

Defined in `imageloader/js/imageloader.js:275`

Displays the images in the group. This method is called when a trigger fires or the time limit expires; it shouldn't be called externally, but is not private in the rare event that it needs to be called immediately.

### `fire`

(

- `type`
- `arguments`

)
EventTarget

Inherited from EventTarget: `event-custom/js/event-target.js:695`

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.

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.

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.

#### Parameters:

- `type` String | Object

  The type of the event, or an object that contains a 'type' property.

- `arguments` Object*

  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:

EventTarget: the event host

### `get`

(

- `name`

)
Any

Inherited from AttributeCore: `attribute/js/AttributeCore.js:353`

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:

- `name` String

  The 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:

Any: The value of the attribute

### `getAttrs`

(

- `attrs`

)
Object

Inherited from AttributeCore: `attribute/js/AttributeCore.js:762`

Gets multiple attribute values.

#### Parameters:

- `attrs` Array | boolean

  Optional. 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:

Object: An object with attribute name/value pairs.

### `getEvent`

(

- `type`
- `prefixed`

)
CustomEvent

Inherited from EventTarget: `event-custom/js/event-target.js:814`

Returns the custom event of the provided type has been created, a falsy value otherwise

#### Parameters:

- `type` String

  the type, or name of the event

- `prefixed` String

  if true, the type is prefixed already

#### Returns:

CustomEvent: the custom event or null

### `getTargets`

()

Inherited from EventTarget: `event-custom/js/event-facade.js:479`

Returns an array of bubble targets for this object.

#### Returns:

EventTarget[]

### `init`

(

- `cfg`

)
BaseCore chainable

Inherited from BaseObservable but overwritten in `base/js/BaseCore.js:264`

Init lifecycle method, invoked during construction. Sets up attributes and invokes initializers for the class hierarchy.

#### Parameters:

- `cfg` Object

  Object with configuration property name/value pairs

#### Returns:

BaseCore: A reference to this object

### `modifyAttr`

(

- `name`
- `config`

)

Inherited from AttributeExtras: `attribute/js/AttributeExtras.js:40`

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.

#### Parameters:

- `name` String

  The name of the attribute whose configuration is to be updated.

- `config` Object

  An object with configuration property/value pairs, specifying the configuration properties to modify.

### `on`

(

- `type`
- `fn`
- `[context]`
- `[arg*]`

)
EventHandle

Inherited from EventTarget: `event-custom/js/event-target.js:188`

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:

- `type` String

  The name of the event

- `fn` Function

  The callback to execute in response to the event

- `[context]` Object optional

  Override `this` object in callback

- `[arg*]` Any optional

  0..n additional arguments to supply to the subscriber

#### Returns:

EventHandle: A subscription handle capable of detaching that subscription

### `once`

(

- `type`
- `fn`
- `[context]`
- `[arg*]`

)
EventHandle

Inherited from EventTarget: `event-custom/js/event-target.js:124`

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:

- `type` String

  The name of the event

- `fn` Function

  The callback to execute in response to the event

- `[context]` Object optional

  Override `this` object in callback

- `[arg*]` Any optional

  0..n additional arguments to supply to the subscriber

#### Returns:

EventHandle: A subscription handle capable of detaching the subscription

### `onceAfter`

(

- `type`
- `fn`
- `[context]`
- `[arg*]`

)
EventHandle

Inherited from EventTarget: `event-custom/js/event-target.js:146`

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:

- `type` String

  The name of the event

- `fn` Function

  The callback to execute in response to the event

- `[context]` Object optional

  Override `this` object in callback

- `[arg*]` Any optional

  0..n additional arguments to supply to the subscriber

#### Returns:

EventHandle: A subscription handle capable of detaching that subscription

### `parseType`

(

- `type`
- `[pre=this._yuievt.config.prefix]`

)
Array

Inherited from EventTarget: `event-custom/js/event-target.js:168`

Available since 3.3.0

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.

#### Parameters:

- `type` String

  the type

- `[pre=this._yuievt.config.prefix]` String optional

  the prefix

#### Returns:

Array: 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`

)
CustomEvent

Inherited from EventTarget: `event-custom/js/event-target.js:493`

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:

- `type` String

  the type, or name of the event

- `opts` Object

  optional 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:

CustomEvent: the custom event

### `registerImage`

(

- ``

)
Object

Defined in `imageloader/js/imageloader.js:256`

Registers an image with the group. Arguments are passed through to a `Y.ImgLoadImgObj` constructor; see that class' attribute documentation for detailed information. "`domId`" is a required attribute.

#### Parameters:

- `` Object multiple

  A configuration object literal with attribute name/value pairs (passed through to a `Y.ImgLoadImgObj` constructor)

#### Returns:

Object: `Y.ImgLoadImgObj` that was registered

### `removeAttr`

(

- `name`

)

Inherited from AttributeExtras: `attribute/js/AttributeExtras.js:79`

Removes an attribute from the host object

#### Parameters:

- `name` String

  The name of the attribute to be removed.

### `removeTarget`

(

- `o`

)

Inherited from EventTarget: `event-custom/js/event-facade.js:489`

Removes a bubble target

#### Parameters:

- `o` EventTarget

  the target to remove

### `reset`

(

- `name`

)
Object chainable

Inherited from AttributeExtras: `attribute/js/AttributeExtras.js:89`

Resets the attribute (or all attributes) to its initial value, as long as the attribute is not readOnly, or writeOnce.

#### Parameters:

- `name` String

  Optional. The name of the attribute to reset. If omitted, all attributes are reset.

#### Returns:

Object: A reference to the host object.

### `set`

(

- `name`
- `value`
- `[opts]`

)
Object chainable

Inherited from AttributeObservable but overwritten in `attribute/js/AttributeCore.js:410`

Sets the value of an attribute.

#### Parameters:

- `name` String

  The 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)`).

- `value` Any

  The value to set the attribute to.

- `[opts]` Object optional

  Optional data providing the circumstances for the change.

#### Returns:

Object: A reference to the host object.

### `setAttrs`

(

- `attrs`
- `[opts]`

)
Object chainable

Inherited from AttributeObservable but overwritten in `attribute/js/AttributeCore.js:729`

Sets multiple attribute values.

#### Parameters:

- `attrs` Object

  An object with attributes name/value pairs.

- `[opts]` Object optional

  Optional data providing the circumstances for the change.

#### Returns:

Object: A reference to the host object.

### `subscribe`

() deprecated

Inherited from EventTarget: `event-custom/js/event-target.js:336`

Deprecated: use on

subscribe to an event

### `toString`

() String

Inherited from BaseCore: `base/js/BaseCore.js:754`

Default toString implementation. Provides the constructor NAME and the instance guid, if set.

#### Returns:

String: String representation for this object

### `unsubscribe`

() deprecated

Inherited from EventTarget: `event-custom/js/event-target.js:459`

Deprecated: use detach

detach a listener

### `unsubscribeAll`

(

- `type`

)
deprecated

Inherited from EventTarget: `event-custom/js/event-target.js:480`

Deprecated: use detachAll

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:

- `type` String

  The type, or name of the event

## Properties

### `_allowAdHocAttrs`

Boolean protected

Inherited from BaseCore: `base/js/BaseCore.js:100`

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.NONATTRS_CFG

Default: undefined (false)

### `_areFoldTriggersSet`

Boolean private

Defined in `imageloader/js/imageloader.js:131`

Boolean tracking whether the window scroll and window resize triggers have been set if this is a fold group.

### `_classImageEls`

Array private

Defined in `imageloader/js/imageloader.js:114`

DOM elements having the class name that is associated with this group. Elements are stored during the `foldCheck` function and reused later during any subsequent `foldCheck` calls - gives a slight performance improvement when the page fold is repeatedly checked.

### `_className`

String private

Defined in `imageloader/js/imageloader.js:123`

Keep the CSS class name in a member variable for ease and speed.

### `_imgObjs`

Object private

Defined in `imageloader/js/imageloader.js:98`

Collection of images (`Y.ImgLoadImgObj` objects) registered with this group, keyed by DOM id.

### `_maxKnownHLimit`

Int private

Defined in `imageloader/js/imageloader.js:139`

The maximum pixel height of the document that has been made visible. During fold checks, if the user scrolls up then there's no need to check for newly exposed images.

### `_timeout`

Object private

Defined in `imageloader/js/imageloader.js:106`

Timeout object to keep a handle on the time limit.

### `_triggers`

Array private

Defined in `imageloader/js/imageloader.js:89`

Collection of triggers for this group. Keeps track of each trigger's event handle, as returned from `Y.on`.

### `name`

String deprecated

Inherited from BaseCore: `base/js/BaseCore.js:242`

Deprecated: Use this.constructor.NAME

The string used to identify the class of this object.

## Attributes

### `className`

String

Defined in `imageloader/js/imageloader.js:55`

Class name that will identify images belonging to the group. This class name will be removed from each element in order to fetch images. This class should have, in its CSS style definition, "`background:none !important;`".

#### Fires event `classNameChange`

Fires when the value for the configuration attribute `className` 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:

- `e` EventFacade
  An Event Facade object with the following attribute-specific properties added:
  - `prevVal` Any
    The value of the attribute, prior to it being set.
  - `newVal` Any
    The value the attribute is to be set to.
  - `attrName` String
    The name of the attribute being set.
  - `subAttrName` String
    If setting a property within the attribute's value, the name of the sub-attribute property being set.

### `classNameAction`

String

Defined in `imageloader/js/imageloader.js:67`

Determines how to act when className is used as the way to delay load images. The "default" action is to just remove the class name. The "enhanced" action is to remove the class name and also set the src attribute if the element is an img.

#### Fires event `classNameActionChange`

Fires when the value for the configuration attribute `classNameAction` 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:

- `e` EventFacade
  An Event Facade object with the following attribute-specific properties added:
  - `prevVal` Any
    The value of the attribute, prior to it being set.
  - `newVal` Any
    The value the attribute is to be set to.
  - `attrName` String
    The name of the attribute being set.
  - `subAttrName` String
    If setting a property within the attribute's value, the name of the sub-attribute property being set.

### `destroyed`

Boolean readonly

Inherited from BaseCore: `base/js/BaseCore.js:157`

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:

- `e` EventFacade
  An Event Facade object with the following attribute-specific properties added:
  - `prevVal` Any
    The value of the attribute, prior to it being set.
  - `newVal` Any
    The value the attribute is to be set to.
  - `attrName` String
    The name of the attribute being set.
  - `subAttrName` String
    If setting a property within the attribute's value, the name of the sub-attribute property being set.

### `foldDistance`

Number

Defined in `imageloader/js/imageloader.js:43`

Distance below the fold for which images are loaded. Images are not loaded until they are at most this distance away from (or above) the fold. This check is performed at page load (domready) and after any window scroll or window resize event (until all images are loaded).

#### Fires event `foldDistanceChange`

Fires when the value for the configuration attribute `foldDistance` 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:

- `e` EventFacade
  An Event Facade object with the following attribute-specific properties added:
  - `prevVal` Any
    The value of the attribute, prior to it being set.
  - `newVal` Any
    The value the attribute is to be set to.
  - `attrName` String
    The name of the attribute being set.
  - `subAttrName` String
    If setting a property within the attribute's value, the name of the sub-attribute property being set.

### `initialized`

Boolean readonly

Inherited from BaseCore: `base/js/BaseCore.js:143`

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:

- `e` EventFacade
  An Event Facade object with the following attribute-specific properties added:
  - `prevVal` Any
    The value of the attribute, prior to it being set.
  - `newVal` Any
    The value the attribute is to be set to.
  - `attrName` String
    The name of the attribute being set.
  - `subAttrName` String
    If setting a property within the attribute's value, the name of the sub-attribute property being set.

### `name`

String

Defined in `imageloader/js/imageloader.js:25`

Name for the group. Only used to identify the group in logging statements.

#### Fires event `nameChange`

Fires when the value for the configuration attribute `name` 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:

- `e` EventFacade
  An Event Facade object with the following attribute-specific properties added:
  - `prevVal` Any
    The value of the attribute, prior to it being set.
  - `newVal` Any
    The value the attribute is to be set to.
  - `attrName` String
    The name of the attribute being set.
  - `subAttrName` String
    If setting a property within the attribute's value, the name of the sub-attribute property being set.

### `timeLimit`

Number

Defined in `imageloader/js/imageloader.js:34`

Time limit, in seconds, after which images are fetched regardless of trigger events.

#### Fires event `timeLimitChange`

Fires when the value for the configuration attribute `timeLimit` 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:

- `e` EventFacade
  An Event Facade object with the following attribute-specific properties added:
  - `prevVal` Any
    The value of the attribute, prior to it being set.
  - `newVal` Any
    The value the attribute is to be set to.
  - `attrName` String
    The name of the attribute being set.
  - `subAttrName` String
    If setting a property within the attribute's value, the name of the sub-attribute property being set.

## Events

### `destroy`

Inherited from BaseObservable: `base/js/BaseObservable.js:151`

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:

- `e` EventFacade

  Event object

### `init`

Inherited from BaseObservable: `base/js/BaseObservable.js:62`

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:

- `e` EventFacade

  Event object, with a cfg property which refers to the configuration object passed to the constructor.