Extending the life of object in cache

There are two way to extend object's life in cache - relative timeframe and fixed timeframe. With the relative timeframe a period of time is added to the timestamp of the call to determine the new expiration time. The fixed timestamp approach sets the timestamp when the object must expire from cache. All methods are available via Backendless.Cache.[methodname] accessor:

// relative time extension
Future<void> Backendless.cache.expireIn(String key, int seconds);

// fixed time extension
Future<void> Backendless.cache.expireAt(String key, {DateTime date, int ;timestamp})

where:

Argument	Description
key	identifies the object to extend the life of in cache.
seconds	number of seconds to extend the life of object in cache by. Must be a value between 1 and 7200 (2 hours).
timestamp	a timestamp in milliseconds when the object should expire and removed from cache. The difference between timestamp and the current time must be equal or less than 7200000 milliseconds (2 hours).

Example

// extend object's life in cache asynchronously by 1200 seconds - 20 minutes
Backendless.cache.expireIn("firstorder", 1200).then((result) {
  print("Object life has been extended");
});

// extend object's life in cache synchronously by 1200 seconds - 20 minutes
int timestamp = DateTime.now().add(Duration(seconds: 1200)).millisecondsSinceEpoch;
Backendless.cache.expireAt( "firstorder", timestamp: timestamp).then((result) {
  print("Object life has been extended");
});