iOS Application Configuration File

Question

In a C# application I always used an app.config file to save some data for my application to load when needed (e.g Connection String).

Wha

Answer 1

If you're just storing a relatively simple set of configuration stuff, you can simply use NSDictionary's serialization methods (I don't know how to link to the methods directory in the class doc):

NSString *settingsPath = [@"~/pathtoconfig.plist" stringByExpandingTildeInPath];

NSMutableDictionary *settings = [NSMutableDictionary dictionary];
if([[NSFileManager defaultManager] fileExistsAtPath:settingsPath]){
    settings = [NSMutableDictionary dictionaryWithContentsOfFile:settingsPath];
}

// writing settings
[settings writeToFile:settingsPath atomically:YES];

Since I don't know how familiar you are with objective-c, I'll also note:

• In iOS, the home directory refers to the application's sandboxed directory.
• I recommend reading a little bit up on reference counting. Although objective-c, as of iOS5, now automatically reference counts for you, there are some edge cases to be aware about (Here's a SO question on ARC)

Answer 2

Updated for Swift 3 Xcode 8

Add a new property list to your project named "Sample.plist". Then see the following example.

    let path: String = Bundle.main.path(forResource: "Sample", ofType: "plist")!
    let sampleConf: NSDictionary = NSDictionary(contentsOfFile: path)!
    print(sampleConf.object(forKey: "test") as! String)

Answer 3

iOS Application Configuration File in Swift with iOS 8.3:

    let path: String = NSBundle.mainBundle().pathForResource("Info", ofType: "plist")!
    let nsDictionaryInfoPlist: NSDictionary = NSDictionary(contentsOfFile: path)!

    // Usage example: Google Maps iOS SDK/API Configuration.
    GMSServices.provideAPIKey(nsDictionaryInfoPlist.objectForKey("GoogleMapsiOSAPIKey") as! String)

Answer 4

I use property lists for storing small pieces of data - have a look here on how to use them:

http://iphoneincubator.com/blog/tag/nspropertylistserialization

Answer 5

You can create a property list file (there is a template for that in XCode, just to to File -> New file and choose there), so you will have something like "settings.plist", or anything like that. You can think of a plist as being a key => value config file, with the difference that you can also hold arrays and dictionaries, besides plain text as value.

Use NSBundle to load the file in your app, like

NSString *path = [[NSBundle mainBundle] pathForResource:@"settings" ofType:@"plist"];
NSDictionary *settings = [[NSDictionary alloc] initWithContentsOfFile:path];

You can then access your keys as a regular dictionary. Just don't forget to [release] it after ;).

Answer 6

For small bits of data like a connection string, I'd use NSUserDefaults.

When you want to save your connection string, you'd do this:

[[NSUserDefaults standardUserDefaults] setObject:myConnectionString 
                                          forKey:@"connectionString"];

When you want to load it, you'd do this:

myConnectionString = [[NSUserDefaults standardUserDefaults] 
                          stringForKey:@"connectionString"];