It's publicly used to identify, which version customer is using and reporting bugs about. However there is a very important technical reason to take good care of version number: Sounds easy, yet again Let's check the documentation:
It is mainbundle write a check simple to use, yet I haven often seen it used incorrectly or inefficiently, especially when it comes to handling default values for preferences. If the defaults database contains no value for the specified key, the boolForKey: The caller has no way of distinguishing between NO and no value; the same is true for the other NSUserDefaults methods that return primitive values, such as integerForKey:.
Workarounds I can think of three obvious workarounds to this problem, all of which are ugly and all of which I have seen in actual production code: Rephrase all user defaults keys so that NO or 0 is the correct default value.
In our example, this would mean renaming "ShowTutorial" to "HideTutorial".
This may be a workable solution for boolean values, but is extremely impractical or impossible for numbers and more complex values. This works but makes the code less readable and more complex than it needs to be.
Write custom code that stores the default values for all preferences in the user defaults on the first launch of your app requiring another flag that tells your app whether it is being launched for the first time or not.
This is essentially what we will do, but in a more elegant way.
Method A better way is to take advantage of the registerDefaults: To edit the default values, you should create a DefaultPreferences.
At runtime, your app can then load that file and pass its contents to registerDefaults:: Note that you have to do this on every launch of your app before you read any values from the user defaults because registerDefaults: Defaults Domains So how does this work?
The user defaults database actually consists of a hierarchy of layers, or domains. Whenever you read the value for a key, NSUserDefaults traverses this domain hierarchy from top to bottom and returns the first value it finds.
It works a bit like the responder chain. Domains can be persistent values are stored on disk or volatile values are only valid for the lifetime of the NSUserDefaults instance. The most important domain is called the application domain.
In contrast, the registerDefaults: There is also a global domain where system-wide settings are stored and language-specific domains that contain regional preferences such as month names or date formats for each locale.
Last but not least, Apple uses the same technique to allow us to override user defaults values via command line arguments.
Since the argument domain has the highest priority of all, we can use it to temporarily override any preference. Most of you probably know that this is very useful for testing a localized app in another language, for instance with -AppleLanguages de 1. In this case, we override the default language, which is normally defined in the global domain.
The complete search order for user defaults domains looks like this: Search order for user defaults domains. Preferences and Settings Programming Guide Domain.1) Create a list of paths.
2) Get a path to your documents directory from the list.
3) Create a full file path. 4) Check if file exists.
5) Get a path to your plist created before in bundle directory (by Xcode). Aug 02, · If you just want to write a code which reads some resource in the Playground, start with adding the resource to the Playground.
Adding Resources to a Playground If you want to test a code which reads or writes arbitrary files, you'd better create a Command Line Tool project. Check here to check to make sure your static library and code header files were extracted properly.
This won’t be created until the first time you build the app in Unreal Editor for iOS. Check here for . Mar 18, · I get one button like I expect, but clicking it has no effect. Interestingly enough, adding a simple alert instead of my Objective-C code doesn't work either.
MD5 (Message-Digest algorithm 5) is a crytographic hash function that is commonly used as a means to verify file integrity. For instance, if you store a file on a server and download the same onto a device, you can compare the server hosted MD5 value to a received copy to verify the file was downloaded intact.
I didn't really pay attention to the posted screenshot, but the target is of type "Command-line Tool" and since those don't have a bundle [NSBundle mainBundle] of course returns nil.
It's pretty misleading that Xcode doesn't complain that it can't execute the "Copy Bundle Resources" step, it just silently skips it.