As we know, a UIApplication instance of an App calls delegate methods to notify developers implementing customizations. In these delegate methods, we can perform our tasks:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // do your massive stuff.....
    
    return YES;
}

For a sophisticated application, this would be a disaster for a developer to maintain.

RWTaskKit is born to solve this issue! It helps programmers to perform tasks separately. Forget AppDelegate from now on!

Here is an examle for a task defined in a .m file:

@task(Task1, RWTaskPriorityCritical, RWTaskEventWillFinishLaunching)
+(void) run {
    NSLog(@"This is No.1 task we want to perform!");
}
@end

method run will be invoked right after application:willFinishLaunchingWithOptions: is called by UIApplication. This code snippet could be in any .m file only with importing RWTask.h

You can see that each task consists of three parts: task identifier with parameters task body task end identifier.

• task identifier with parameters

1. start with @ character just like annotation in Java
2. followed by a keyword identifying type of task
3. followed by a set of parameters

• task body

  consists of one or two objective-c class method.

• task end identifier

  just an end

RWTaskKit supports three types of task:event task schedule task notification task

Event task is designed to handle common methods calling in UIApplicationDelegate.

Parameters in the brackets are :Task Name, Priority, Event Name

Task Nanme would be any unique string. Priority would be enumeration value witch can be found in RWTaskObject.h, task (for a same event) with higher priority will be exexuted earlier.

Event Name would be enumeration value as following：

typedef NS_ENUM(NSUInteger, RWTaskEvent) {
  RWTaskEventWillFinishLaunching = 0x1,       //tasks will be performed only once
  RWTaskEventDidFinishLaunching = 0x1 << 1,   //tasks will be performed only once
  RWTaskEventWillEnterForeground = 0x1 << 2,
  RWTaskEventDidEnterBackground = 0x1 << 3,
  RWTaskEventDidBecomeActive = 0x1 << 4,
  RWTaskEventDidReceiveMemoryWarning = 0x1 << 5,
  RWTaskEventWillTerminate = 0x1 << 6,
  RWTaskEventWillResignActive = 0x1 << 7,
  RWTaskEventSignificantTimeChange = 0x1 << 8,
  RWTaskEventOpenURL = 0x1 << 9,
  RWTaskEventWillChangeStatusBarOrientation = 0x1 << 10,
  RWTaskEventDidChangeStatusBarOrientation = 0x1 << 11,
  RWTaskEventBackgroundRefreshStatusDidChange = 0x1 << 12,
  RWTaskEventUserDidTakeScreenshot = 0x1 << 13,
  RWTaskEventReserved1 = 0x1 << 14,
  RWTaskEventReserved2 = 0x1 << 15,
  RWTaskEventIdle = 0x1 << 16, // not implemented
  RWTaskEventNone = 0,
};

Above event enumerations are mapped to coresponding delegate methods. see UIApplication.h in iOS SDK.

class method run is a must-have for any task. Besides event task has an optional method +(NSArray<Class>*)dependency which denotes the dependency of the task. See the following example:

@task(Task2, RWTaskPriorityCritical, RWTaskEventWillFinishLaunching)
+(void) run {
    NSLog(@"This is No.2 task we want to perform!");
}
+(NSArray<Class>*)dependency{
  	// this task will be executed after Task1 and Task3 finish
	return @[task_name(Task1),task_name(Task3)];    
}
@end

Here task_name is a macro for convenience. Tasks specified in method dependency have nothing to do with the order inside the array.

Schedule task is designed for the task should be executed right after a scheduled time or repeated with specified times.

examples:

@schedule(ScheduleTask1, 1448873913, 5, 1)
+ (void) run{
  NSLog(@"hello");
}
@end
 
@timer(ScheduleTask2, 10, 2)
+ (void) run{
  NSLog(@"hello");
}
@end

ScheduleTask1 will be executed right after 1448873913(timestamp, like [[NSDate date] timeIntervalSince1970]), it will be executed 5 times for every 1 second.

ScheduleTask2 will be executed every 2 seconds, and it will repeat 10 times.

Schedule task has a built-in clock, the time interval is 1 second. Thus the timeinterval in paramters should be an integral multiple of built-in time interval. Besides the maximum timeinterval is 120 * built-in time interval.

Note: developers can customize the built-in time interval by trigger a repeatedly notification implused by your own NSTimer.

First, use NO_RW_CLOCK macro only once in any .m file. Second, post a notification with name RWAppClockTicktockNotificationKey in your customized timer.

Notification task is designed for task should be triggered by a notification. Example:

@notification(NotiTask,@"NotificationKey")
+ (void) runWithNotification:(NSNotification*)noti{
  NSLog(@"hello");
}
@end

Following interfaces can be used in runtime scenario to inject event tasks and schedule tasks.

- (void)injectEventTaskWithName:(NSString *)taskName
                  andBlock:(RWTaskBlock)block
                  priority:(RWTaskPriority)p
              triggerEvent:(RWTaskEvent)e
                dependency:(NSArray<Class> *)dependency
                autoRemove:(BOOL)autoRemove;
		
- (void)scheduleTaskWithName:(NSString *)taskName
                    andBlock:(RWTaskBlock)block
                 desiredDate:(NSDate *)date
                 repeatCount:(NSInteger)count
                timeInterval:(NSUInteger)timeInterval;

- (void)destroyTaskByName:(NSString *)taskName;

- (void)pauseTaskByName:(NSString *)taskName;

- (void)resumeTaskByName:(NSString *)taskName;