Package org.wicketstuff.offline.mode

Class OfflineCache

java.lang.Object
org.wicketstuff.offline.mode.OfflineCache
public class OfflineCache extends Object
The offline cache to initialize / load the client side cache.

Example: 

 List<OfflineCacheEntry> offlineCacheEntries = new ArrayList<>();
 offlineCacheEntries.add(new OfflineCacheEntry().setCacheObject(new CssResourceReference(HomePage.class, "main.css")));
 offlineCacheEntries.add(new OfflineCacheEntry().setCacheObject(HomePage.class));
 OfflineCache.init(this, "MyCache-1", offlineCacheEntries);
To contribute the offline cache use the following snippet in the renderHead method of a page: 
 
 OfflineCache.renderHead(response);
If the cache name is going to be changed all resources are going to be reloaded again. This happens if the browser loads the new service worker content (after a browser refresh). The new service worker is going to be initialized as "waiting". (See chapter "How to Update a Service Worker" of the html5 rocks article) If you then switch the page to google for example and switch back, the new content is going to be shown up and the old service worker is going to be marked as "REDUNDANT". You have to leave the page with ALL tabs! Wicket handles older caches to be invalid and clear them - so when you switch from "MyCache-1" to "MyCache-2" all entries of "MyCache-1" are going to be cleared.

For more information see:

- https://www.w3.org/TR/service-workers/#navigator-service-worker-waiting
- https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API
- http://www.html5rocks.com/en/tutorials/service-worker/introduction/
- http://caniuse.com/#search=Service%20Worker
Important: local development can be achieved through HTTP (localhost, 0.0.0.0, 127.0.0.1), with DNS you have to use HTTPS! Service worker only running with HTTPS if not local.


Author:
Tobias Soloschenko

  • Constructor Details

    • OfflineCache

      public OfflineCache()

  • Method Details

    • init

      public static void init(WebApplication webApplication, String cacheName, List<OfflineCacheEntry> offlineCacheEntries)
      Initializes the offline cache (used in the init method of a wicket application)
      Parameters:
      webApplication - the web application to mount the offline cache references
      cacheName - the cache name
      offlineCacheEntries - the offline cache entries to be cached

    • renderHead

      public static void renderHead(IHeaderResponse response)
      Loads the service worker registration and the service worker implementation java script references
      Parameters:
      response - the response to contribute the offline cache references

    • getOfflineCacheEntries

      public static List<OfflineCacheEntry> getOfflineCacheEntries(WebApplication application)
      Gets the offline cache entries
      Returns:
      the offline cache entries

    • setOfflineCacheEntries

      public static void setOfflineCacheEntries(WebApplication application, List<OfflineCacheEntry> offlineCacheEntries)
      Sets the offline cache entries (can only be used if the offline cache hasn't been initialized yet)
      Parameters:
      application - the application instance
      offlineCacheEntries - the offline cache entries to store