2.1.0: Merge pull request #86 from tumblr/feature/add-back-notification-obse…

Removes the need for the explicit memory warning and application background handling, which was an ill-advised change in 2.0.

The other part of the 2.0 release still applies; you need to explicitly provide an object that knows how to vend background tasks in order for operations to continue after your application has been backgrounded.

2.0.0

2.0.0 removes all references to UIApplication sharedApplication. As of iOS 8, this method is annotated with NS_EXTENSION_UNAVAILABLE_IOS, meaning that it won’t compile as part of an iOS 8 extension. In order to facilitate TMCache usage inside extensions.

TMCache previously used UIApplication for two different functions:

• Wrapping work in background tasks, to ensure that it completes even if the user backgrounds the application
• Listening for UIApplicationDidEnterBackgroundNotification and UIApplicationDidReceiveMemoryWarningNotification, in order to perform some cleanup work

If you still want this behavior, it’s now up to you to implement this behavior in your application code. Thankfully, doing so is extremely straightforward:

Background tasks

Create a class that conforms to TMCacheBackgroundTaskManager. Your implementation will likely look very much like this:

Objective-C:

@interface BackgroundTaskManager: NSObject <TMCacheBackgroundTaskManager>

@implementation BackgroundTaskManger

- (UIBackgroundTaskIdentifier)beginBackgroundTask {
    UIBackgroundTaskIdentifier taskID = UIBackgroundTaskInvalid;

    [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
        [[UIApplication sharedApplication] endBackgroundTask:taskID];
    }];

    return taskID;
}

- (void)endBackgroundTask:(UIBackgroundTaskIdentifier)identifier {
    [[UIApplication sharedApplication] endBackgroundTask:identifier];
}

@end

Swift:

class BackgroundTaskManager: NSObject, TMCacheBackgroundTaskManager {
    private let application = UIApplication.sharedApplication()

    func beginBackgroundTask() -> UInt {
        let taskID = UIBackgroundTaskInvalid

        application.beginBackgroundTaskWithExpirationHandler {
            self.application.endBackgroundTask(taskID)
        }

        return UInt(taskID)
    }

    func endBackgroundTask(identifier: UInt) {
        application.endBackgroundTask(Int(identifier))
    }
}

Then, pass an instance of your class to the following TMDiskCache class method:

[TMDiskCache setBackgroundTaskManager:[[BackgroundTaskManager alloc] init]];

Clean-up on memory warning/backgrounding notifications

TMMemoryCache has new public methods that can be called in the event of a memory warning or application backgrounding, in order to easily replicate TMCache 1.X.X behavior:

Objective-C:

[[NSNotificationCenter defaultCenter] addObserver:memoryCache
                                         selector:@selector(handleMemoryWarning)        
                                             name:UIApplicationDidReceiveMemoryWarningNotification     
                                           object:[UIApplication sharedApplication]];

[[NSNotificationCenter defaultCenter] addObserver:memoryCache
                                         selector:@selector(handleApplicationBackgrounding)        
                                             name:UIApplicationDidEnterBackgroundNotification     
                                           object:[UIApplication sharedApplication]];

Swift:

NSNotificationCenter.defaultCenter().addObserver(memoryCache, selector: "handleMemoryWarning", name: UIApplicationDidReceiveMemoryWarningNotification, object: UIApplication.sharedApplication())

NSNotificationCenter.defaultCenter().addObserver(memoryCache, selector: "handleApplicationBackgrounding", name: UIApplicationDidEnterBackgroundNotification, object: UIApplication.sharedApplication())

1.2.3

• [fix] TMDiskCache/TMMemoryCache: import UIKit to facilitate Swift usage (thanks digabriel!)
• [fix] TMDiskCache: add try catch to ensure an exception isn’t thrown if a file on disk is unable to be unarchived (thanks leonskywalker!)
• [fix] TMDiskCache: create trash directory asynchronously to avoid race condition (thanks napoapo77!)