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ContentCache

Package | spark.core
Class | public class ContentCache
Inheritance | ContentCache flash.events.EventDispatcher
Implements | IContentLoader

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Provides a caching and queuing image content loader suitable for using a shared image cache for the BitmapImage and spark Image components.

Public Properties

| Property | Defined By
--- | --- | ---
|  | enableCaching : Boolean Enables caching behavior and functionality. | ContentCache
|  | enableQueueing : Boolean Enables queuing behavior and functionality. | ContentCache
|  | maxActiveRequests : int Maximum simultaneous active requests when queuing is enabled. | ContentCache
|  | maxCacheEntries : int Maximum size of MRU based cache. | ContentCache
|  | numCacheEntries : int [read-only] Count of active/in-use cache entries. | ContentCache

Protected Properties

| Property | Defined By
--- | --- | ---
|  | activeRequests : LinkedList List of queued CacheEntryNode instances currently executing. | ContentCache
|  | cachedData : Dictionary Map of source to CacheEntryNode. | ContentCache
|  | cacheEntries : LinkedList Ordered (MRU) list of CacheEntryNode instances. | ContentCache
|  | priorityGroup : String = _DEFAULT_ Identifier of the currently prioritized content grouping. | ContentCache
|  | requestQueue : LinkedList List of queued CacheEntryNode instances. | ContentCache

Public Methods

| Method | Defined By
--- | --- | ---
|  | ContentCache() Constructor. | ContentCache
|  | addCacheEntry(source:Object, value:Object):void Adds new entry to cache (or replaces existing entry). | ContentCache
|  | getCacheEntry(source:Object):Object Obtain an entry for the given key if one exists. | ContentCache
|  | load(source:Object, contentLoaderGrouping:String = null):ContentRequest Initiates a content request for the resource identified by the key specified. | ContentCache
|  | prioritize(contentLoaderGrouping:String):void Promotes a content grouping to the head of the loading queue. | ContentCache
|  | removeAllCacheEntries():void Resets our cache content to initial empty state. | ContentCache
|  | removeAllQueueEntries():void Resets the queue to initial empty state. | ContentCache
|  | removeCacheEntry(source:Object):void Remove specific entry from cache. | ContentCache

Events

| Event | Summary | Defined By
--- | --- | --- | ---
|  | invalidateLoader | Dispatched when a cache entry is invalidated, generally this occurs when the entry is determined to be untrusted while one or more outstanding load requests are active for a given cache entry. | ContentCache

Protected Constants

| Constant | Defined By
--- | --- | ---
|  | UNTRUSTED : String = untrusted [static] Value used to mark cached URLs that are detected as being from an untrusted source (meaning they will no longer be shareable). | ContentCache

Property Detail

activeRequests | property

`protected var activeRequests:LinkedList`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

List of queued CacheEntryNode instances currently executing.

cachedData | property |

`protected var cachedData:Dictionary`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Map of source to CacheEntryNode.

cacheEntries | property |

`protected var cacheEntries:LinkedList`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Ordered (MRU) list of CacheEntryNode instances.

enableCaching | property |

`enableCaching:Boolean`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Enables caching behavior and functionality. Applies only to new load() requests.

The default value is `true`.

Implementation
`public function get enableCaching():Boolean`
`public function set enableCaching(value:Boolean):void`

enableQueueing | property |

`enableQueueing:Boolean`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Enables queuing behavior and functionality. Applies only to new load() requests.

The default value is `false`.

Implementation
`public function get enableQueueing():Boolean`
`public function set enableQueueing(value:Boolean):void`

maxActiveRequests | property |

`maxActiveRequests:int`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Maximum simultaneous active requests when queuing is enabled.

The default value is `2`.

Implementation
`public function get maxActiveRequests():int`
`public function set maxActiveRequests(value:int):void`

maxCacheEntries | property |

`maxCacheEntries:int`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Maximum size of MRU based cache. When numCacheEntries exceeds maxCacheEntries the least recently used are pruned to fit.

The default value is `100`.

Implementation
`public function get maxCacheEntries():int`
`public function set maxCacheEntries(value:int):void`

numCacheEntries | property |

`numCacheEntries:int` [read-only]

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Count of active/in-use cache entries.

Implementation
`public function get numCacheEntries():int`

priorityGroup | property |

`protected var priorityGroup:String = _DEFAULT_`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Identifier of the currently prioritized content grouping.

The default value is `"_DEFAULT_"`.

requestQueue | property |

`protected var requestQueue:LinkedList`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

List of queued CacheEntryNode instances.

Constructor Detail

ContentCache | () | Constructor

`public function ContentCache()`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Constructor.

Method Detail

addCacheEntry | () | method

`public function addCacheEntry(source:Object, value:Object):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Adds new entry to cache (or replaces existing entry).

Parameters

| `source:Object` — Unique key to associate provided value with in cache.
| `value:Object` — Value to cache for given key.

getCacheEntry | () | method |

`public function getCacheEntry(source:Object):Object`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Obtain an entry for the given key if one exists.

Parameters

| `source:Object` — Unique key used to represent the requested content resource.

Returns

| `Object` — A value being stored by the cache for the provided key. Returns null if not found or in the likely case the value was stored as null.

load | () | method |

`public function load(source:Object, contentLoaderGrouping:String = null):ContentRequest`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 2.5

Initiates a content request for the resource identified by the key specified.

Parameters

| `source:Object` — Unique key used to represent the requested content resource. This parameter is typically an URL or URLRequest.
| `contentLoaderGrouping:String` (default = `null`)`` — - (Optional) grouping identifier for the loaded resource. ContentLoader instances supporting content groups generally allow for resources within the same named grouping to be addressed as a whole. For example the ContentCache's loader queue allows requests to be prioritized by contentLoaderGrouping.

Returns

| `ContentRequest` — A ContentRequest instance representing the requested resource.

prioritize | () | method |

`public function prioritize(contentLoaderGrouping:String):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Promotes a content grouping to the head of the loading queue.

Parameters

| `contentLoaderGrouping:String` — Name of content grouping to promote in the loading queue. All queued requests with matching contentLoaderGroup will be shifted to the head of the queue.

removeAllCacheEntries | () | method |

`public function removeAllCacheEntries():void`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Resets our cache content to initial empty state.

removeAllQueueEntries | () | method |

`public function removeAllQueueEntries():void`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Resets the queue to initial empty state. All requests, both active and queued, are cancelled. All cache entries associated with canceled requests are invalidated.

removeCacheEntry | () | method |

`public function removeCacheEntry(source:Object):void`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 1.5

Remove specific entry from cache.

Parameters

| `source:Object` — Unique key for value to remove from cache.

Event Detail

invalidateLoader | Event

Event Object Type: `spark.events.LoaderInvalidationEvent`
LoaderInvalidationEvent.type property = `spark.events.LoaderInvalidationEvent`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 10, AIR 2.0

Dispatched when a cache entry is invalidated, generally this occurs when the entry is determined to be untrusted while one or more outstanding load requests are active for a given cache entry. This mechanism allows any outstanding content requests to be reset due to the fact that the cache entry has been deemed 'unshareable'. Each content request notified then attempts instead re-requests the asset.

Constant Detail

UNTRUSTED | Constant

`protected static const UNTRUSTED:String = untrusted`

Language Version : | ActionScript 3.0

Product Version : | Flex 4.5

Runtime Versions : | Flash Player 9, AIR 1.1

Value used to mark cached URLs that are detected as being from an untrusted source (meaning they will no longer be shareable).

Wed Nov 15 2017, 09:50 AM +01:00