ncCache

ncCache is a simple wrapper over a pre-built local storage plugin, which includes many options such as absolute expiration, sliding expiration, cache priority, and a callback function. ncCache even supports local storage on those browsers which themselves don’t support local storage. It can be used to cache data locally in the user's browser, saving a server roundtrip in web applications, hence improving page performance.

How It Works

• Create a new cache item

• var cache = ncCacheFactory.getCache(projectName);
  

• Add an item to the cache

  Parameters:

  • key - the key to refer to the object
  • value - the object to cache options. An optional parameter described below the last parameter accepts an object which controls various caching options:
    • expirationAbsolute: the datetime when the item should expire
    • expirationSliding: an integer representing the seconds since the last cache access after which the item should expire.

• Priority : How important it is to leave this item in the cache. You can use the values Cache.Priority.LOW, .NORMAL, or .HIGH, or you can just use an integer.

• Note that placing a priority on an item does not guarantee it will remain in cache. It can still be purged if an expiration is hit, or if the cache is full.

• callback: A function that gets called when the item is purged from cache. The key and value of the removed item are passed as parameters to the callback function. cache.setItem("A", "1", {expirationAbsolute: null, expirationSliding: 60, priority: Cache.Priority.HIGH, callback: function(k, v) { alert('removed ' + k); } });

    // retrieve an item from the cache
    // takes one parameter, the key to retreive
    // returns the cached item
    cache.getItem("A");
  
    // Remove and return an item from the cache.
    // If the item doesn't exist it returns null.
    cache.removeItem("A");
    
    // Removes items from the cache which pass the provided test.
    // If the test function returns true, the item will be removed.
    // E.g., Remove keys which start with 'RemoveMe'
    cache.removeWhere(function(k, v) { return /^RemoveMe/.test(k); });
  
    // Returns the number of items in the cache.
    cache.size();
  
    // Return stats about the cache, like {"hits": 1, "misses": 4}
    cache.stats();
  
    // clears all items from the cache
    cache.clear();
  

KNOWN LIMITATIONS (IMPORTANT):

As per IE 7's documentation available here:
http://msdn.microsoft.com/en-us/library/ms531424(v=vs.85).aspx

a UserData store is available only in the same directory and with the same protocol used to persist the store

In other words, data stored in IE 7 at this URL: http://example.com/foo will NOT BE AVIALBLE at the URL: http://example.com/bar and will also not be available at the URL: https://example.com/foo

Dependencies:

If IE 7 support is required, this library requires that jQuery 1.x should be already included in the page.