service.md

Service

Manipulate caches and cache items defined through the Service Provider.

httpEtag Service

Example Usage:

.controller('MyCtrl', function (httpEtag) {
  // Get the default cache
  var cache = httpEtag.getCache()
  cache.info()
  // { id: 'httpEtagCache',
  //   deepCopy: false,
  //   cacheResponseData: true,
  //   cacheService: '$cacheFactory',
  //   cacheOptions: { number: 25 } }

  cache.setItem('myItemKey', [{ hello: 'world' }])
  cache.getItem('myItemKey') //> [{ hello: 'world' }]

  // Get itemKey-bound itemCache object
  var itemCache = cache.getItemCache('myItemKey') // or httpEtag.getItemCache('httpEtagCache', 'myItemKey')
  itemCache.info()
  // { id: 'httpEtagCache',
  //   itemKey: 'myItemKey',
  //   deepCopy: false,
  //   cacheResponseData: true,
  //   cacheService: '$cacheFactory',
  //   cacheOptions: { number: 25 } }

  itemCache.get() //> [{ hello: 'world' }]
  itemCache.unset()

  cache.getItem('myItemKey') //> undefined
})

Service Methods

Method	Details
info()	Returns an object with information about the cache configuration.
getCache([cacheId])	Returns a cache object matching the specified cacheId. If no cacheId is specified, the default cache is returned.
getItemCache(cacheId, itemKey)	Returns an itemCache—a cache object that's bound to the specified item. A shortcut for httpEtag.getCache('id').getCacheItem('itemKey').
purgeCaches()	Remove all cache items from all defined caches.

There are two kinds of cache objects. A cache and an itemCache. A cache object can interact with all items or a specific item within that cache. An itemCache only interacts with a specific item in a cache. They share many of the same methods, but with a small difference in naming. The itemCache is detailed below.

cache Object

On setItem and getItem options: Some cache services may allow for additional options to be passed when setting or getting cache data; $cacheFactory, localStorage, and sessionStorage do not, but a third-party cache service defined using a Cache Service Adapter may.

Method	Details
info()	Returns an object with information about the cache configuration, including cache ID.
setItem(itemKey, value[, options])	Insert a value into the cache under the itemKey.
getItem(itemKey[, options])	Retrieve data from the cache under the itemKey.
unsetItem(itemKey)	Unset data in the cache under the itemKey. This does not remove a cached ETag header associated with the cache item.
expireItem(itemKey)	Unset a cached ETag associated with this cache item. This does not remove data stored in the cache item.
removeItem(itemKey)	Remove the cached data and ETag associated with the specified itemKey.
removeAllItems()	Remove cached data and ETags from all items stored in the cache.
getItemCache(itemKey)	Retrieve an itemCache object bound to the specified itemKey.

itemCache Object

When using an ETag cache with the $http service, an itemCache object is passed as the 5th argument to success and cached callbacks. Read more about the $http Decorator here.

Method	Details
info()	Returns an object with information about the cache configuration, including cache ID and cache item key.
set(value[, options])	Insert a value into the cache item.
get([options])	Retrieve data from the cache item.
unset()	Unset data in the cache item. This does not remove a cached ETag header associated with the cache item.
expire()	Unset a cached ETag associated with this cache item. This does not remove data stored in the cache item.
remove()	Remove the cached data and ETag associated with the cache item.