lion/packages/ajax/docs/cache-technical-docs.md

Ajax Cache

Technical documentation

The library consists of 2 major parts:

1. A cache class
2. Request and Response Interceptors

Cache class

The cache class is responsible for keeping cached data and keeping it valid. This class isn't exposed outside, and remains private. Together with this class we provide a getCache(cacheIdentifier) method that enforces a clean cache when the cacheIdentifier changes.

Note

: the cacheIdentifier should be bound to the users session.
Advice: Use the sessionToken as cacheIdentifier

Core invalidation rules are:

1. The LionCache instance is bound to a cacheIdentifier. When the getCache receives another token, all instances of LionCache will be invalidated.
2. The LionCache instance is created with an expiration date one hour in the future. Each method on the LionCache validates that this time hasn't passed, and if it does, the cache object in the LionCache is cleared.

Request and Response Interceptors

The interceptors are the core of the logic of when to cache.

To make the cache mechanism work, these interceptors have to be added to an ajax instance (for caching needs).

The request interceptor's main goal is to determine whether or not to return the cached object. This is done based on the options that are being passed to the factory function.

The response interceptor's goal is to determine when to cache the requested response, based on the options that are being passed in the factory function.

Interceptors require cacheIdentifier function and cacheOptions config. The configuration is used by the interceptors to determine what to put in the cache and when to use the cached data.

A cache configuration per action (pre get etc) can be placed in ajax configuration in lionCacheOptions field, it needed for situations when you want your, for instance, get request to have specific cache parameters, like timeToLive.