Selene 2.0.0

Selene 2.0.0

LangLanguage Obj-CObjective C
License Apache-2.0
ReleasedLast Release Sep 2018

Maintained by Kirollos Risk, Jacek Suliga.

Selene 2.0.0

Selene: Background Task Scheduler

Selene is an iOS library which schedules the execution of tasks on a background fetch.

Build Status



Add to your Podfile: pod Selene


You can also add this repo as a submodule and copy everything in the Selene folder into your project.


1) Add the fetch background mode in your app’s Info.plist file.

2) Create a task

A task must conform to SLNTaskProtocol. For example:

@interface SampleTask: NSObject<SLNTaskProtocol>

@implementation SampleTask

+ (NSString *)identifier {
  return NSStringFromClass(self);

+ (NSOperation *)operationWithCompletion:(SLNTaskCompletion_t)completion {
  NSOperation *operation = [NSBlockOperation blockOperationWithBlock:^{
    // Do some work ....
  return operation;

+ (CGFloat)averageResponseTime {
  return 5.0;

+ (SLNTaskPriority)priority {
  return SLNTaskPriorityLow;


3) Add the task class to the scheduler

NSArray *tasks = @[[SomeTask class]];
// Run the scheduler every 5 minutes
[SLNScheduler setMinimumBackgroundFetchInterval:60 * 5];
// Add the tasks
[SLNScheduler scheduleTasks:tasks];

In the application delegate:

- (void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
  [SLNScheduler startWithCompletion:completionHandler];

Interested? Here's the blog post