We are excited to announce a new feature of offline caching and storage in App42 Android SDK. This will enable your application to be responsive even if the network is not available, so the user can use your application flawlessly without any trouble. Using this feature is quite straightforward and requires a single line of code to enable.

Below are the different policies and mechanisms of this feature.

Offline Caching

Offline caching enables your application to read data from the local cache if the network is not available. There are different cache levels that can be set using API and are explained below.

Cache Policies

1) Policy.CACHE_FIRST – Setting this policy will enable all read data to be first looked into the cache if data is available and not expired, then it will return from the cache; otherwise, network request will be made and the cache will be updated. You can set the cache expiry time by using an API, as explained below. By default, cache expiry is set to an hour.

// Setup caching policy

import com.shephertz.app42.paas.sdk.android.App42CacheManager;
import com.shephertz.app42.paas.sdk.android.App42CacheManager.Policy;

App42API.initialize(this, "<YOUR_API_KEY>", "<YOUR_SECRET_KEY>");
App42CacheManager.setPolicy(Policy.CACHE_FIRST); ; 
//Same can be done for network policy

//Set Cache Expiry time. Applicable only for CACHE_FIRST
App42CacheManager.setExpiryInMinutes("");

2) Policy.NETWORK_FIRST – This policy enables data to be fetched from the network and then update the cache. If the network is not available, data is fetched from the cache.

3) Policy.NOCACHE – By default, App42 SDK uses this policy and does not use any cache and always reads data from network only.

Offline storage

Offline storage allows you to post data locally in case the network is not available, and syncs it with the server later when the network is available. This is useful in many scenarios, e.g. if your user is playing a game and has scored something upon completion of a specific level. However, at the time of posting the score, if the network is not available, his score might get lost and his efforts will go to waste. This can be avoided using offline caching, where his score will be saved locally in case of network unavailability and will be later synced with the server when network availability resumes.

To use this feature, you just have to set offline storage to true, as shown below.

App42API.setofflineStorage(true) // just set offline storage true
scoreBoardService.saveUserScore(gameName, userName, gameScore,new App42CallBack() {
public void onSuccess(Object response)
{
  Game game = (Game)response;
  if(game.isOfflineSync())
   {
    System.out.println("Information is Stored in cache, will send to App42 when network is available");
   }
  else
   {
    System.out.println("Game Name is : "+game.getName());
     for(int i = 0;i<game.getScoreList().size();i++)
      {
       System.out.println("userName is : " + game.getScoreList().get(i).getUserName());
       System.out.println("score is : " + game.getScoreList().get(i).getValue());
       System.out.println("scoreId is : " + game.getScoreList().get(i).getScoreId());
       System.out.println("Created On is :"+game.getScoreList().get(i).getCreatedOn());
      }
    }
}
public void onException(Exception ex)
{
 System.out.println("Exception Message"+ex.getMessage());
}
});

Isn’t this simple and straightforward? To get started, sign up here and grab our new Android SDK to give a better user experience to your app users.