January 2017 – Malcolm Hall

Xcode

Where to find IOKit headers for iOS

Sometimes when compiling more sophisticated iOS projects you need the IOKit headers which were removed from the iOS SDK a few versions ago. A simple workaround is to copy them from the Mac OS SDK to the iOS SDK with these commands: sudo cp -r /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/IOKit.framework/Versions/A/Headers /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/Frameworks/IOKit.framework Sometimes you also need OSTypes.h from Read more…

By malhal, 7 years ago

Objective-C

Default behaviour of UISplitViewController collapseSecondaryViewController

The documentation for UISplitViewControllerDelegate collapseSecondaryViewController says: When you return NO, the split view controller calls the collapseSecondaryViewController:forSplitViewController: method of the primary view controller, giving it a chance to do something with the secondary view controller’s content. Most view controllers do nothing by default but the UINavigationControllerclass responds by pushing the secondary view controller onto its navigation stack. Read more…

By malhal, 7 years27th January 2017 ago

CloudKit

CloudPhotos – Apple CloudKit Sample

CloudPhotos : Using CloudKit with iOS is an interesting Apple sample project, last updated a year ago, I thought I would blog about some observations I had. The table view controller uses an array of CKRecords for its data. I sort of remember Apple saying not to use CKRecord as your Read more…

By malhal, 7 years14th January 2017 ago

CloudKit

CloudKit Sync Nightmare

So after previous post on analysing the web requests, where we found out the classes involved and sort of when they should be used, we are still clueless as to how to structure our app to enable CloudKit syncing. We know we shouldn’t subclass fetch operation but then how should we Read more…

By malhal, 7 years13th January 2017 ago

CloudKit

Investigating CloudKit Sync in the Apple News App

Introduction Syncing data across a user’s own devices in a privacy-sensitive way is one of the flagship features of CloudKit. Unfortunately many agree “it isn’t as documented as it might be”, e.g. there is no sync sample from Apple, the WWDC 2014 talk and WWDC 2015 talk didn’t quite get Read more…

By malhal, 7 years10th January 2017 ago

Objective-C

ObjC Delegation and Notifications

I was researching the different ways people are implementing the part of MVC where the model notifies the controller about new data. A limitation of the delegate pattern is only one class can be the delegate, for other classes to listen then they need to use Notification Center notifications (or Read more…

By malhal, 7 years8th January 2017 ago

Objective-C

NSArray @property backed by a NSMutableArray

Saw a bunch of posts today on Stack Overflow asking how to implement this: NSArray @property backed by a NSMutableArray Hiding privately mutable properties behind immutable interfaces in Objective-C (my answer) Protect from adding object to NSMutableArray in public interface Having readonly nsarray property and nsmutable array not readonly with the Read more…

By malhal, 7 years8th January 2017 ago

NSOperation

NSOperationQueue maxConcurrentOperationCount 1 Serial Queue Problem

Around the web and even in Apple’s WWDC 2015 Advanced NSOperations talk they say: “If we set the max concurrent operation count of an NSOperationQueue to be 1, then we essentially make our NSOperationQueue into a serial operation queue.” Sometimes developers also refer to this configuration as a first in first Read more…

By malhal, 7 years7th January 2017 ago

CloudKit

YapDatabase Disappointing CloudKit Example

It’s not often you see code as disappointing as this, particularly because CloudKit is so well designed for the situation being described, but it’s actually very common. I think it happens when you have a developer with speciality in one area, trying to apply it to their understanding of how to Read more…

By malhal, 7 years6th January 2017 ago

Xcode

Xcode 8 iOS 10 Non-Stop Device Logs

This post is about my Stack Overflow answer. In Xcode, Window->Devices, choosing a device and clicking the up arrow in the bottom bar brings up the console and this traditionally allowed you to view output from your app when not running in the debugger, e.g. for testing background launching behaviour. Unfortunately as of Read more…

By malhal, 7 years6th January 2017 ago