I have a couple questions regarding application preferences using NSUserDefaults.
In my last app I would link my preferences using bindings to NSUserDefaults, and this worked perfectly. In the application startup methods I could then perform actions based on the values stored in the NSUserDefaults.
The problem occured when I updated my application and re-distributed it, in which all the settings would get over-written with the preferences in my computer. So if someone changed the settings, and then received the update, their settings would get over-written with mine.
Looking back at the Apple documentation in regards to saving Preferences, I notice the following line which I didn't use, which is used to write preferences to disk:
[defaults synchronize];
My question is, does this code write the preferences to the user's harddrive, so that if I re-distribute the application with different settings, NSUserDefaults will read from the disk instead?
Sorry for the misunderstanding but I can't find an answer.
Thanks in advance everyone.
If you want to use bindings to control your preferences, you should be using NSUserDefaultsController. In either case, to set initial values for your defaults, you should create a dictionary with the initial values and then pass it to registerDefaults: if you're using vanilla NSUserDefaults, or one of initWithDefaults:initialValues: or setInitialValues: if you're using NSUserDefaultsController. Here's an NSUserDefaultsExample:
- (void)applicationDidFinishLaunching {
// For decent-sized applications, I normally like to store this in its own plist
// but I'm creating it in-line here for readability's sake.
NSDictionary *initialPreferences = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInteger:21], #"UserAge",
#"red", #"FavoriteColor",
#"Idaho", "Location", nil];
[[NSUserDefaults standardUserDefaults] registerDefaults:initialPreferences];
}
NSUserDefaults are only written when synchronize is called.
When you ship your app and you want specific settings in place at first launch, you need to set these yourself in code. I usually look for a nil value for a specific key and if it an empty value, I will set the desired "default" value.
Example
I do this when the application launches:
NSUserDefaults * defaults = [NSUserDefaults standardUserDefaults];
/* count how many times the user has launched the app */
int total = [[defaults objectForKey:#"kLaunchCount"] intValue]; total++;
[defaults setObject:[NSNumber numberWithInt:total] forKey:#"kLaunchCount"];
/* User chose to reset Scanner Feed, remove the .plist from Documents directory. */
if ( [[defaults objectForKey:#"kResetScannerFeeds"] boolValue] == YES ){
[[NSFileManager defaultManager] removeItemAtPath:SCANNERFEED error:nil];
[defaults setObject:[NSNumber numberWithBool:NO] forKey:#"kResetScannerFeeds"];
}
/* Check to see if Default Prefs are NULL, if so, enable them. */
if ( [defaults objectForKey:#"kShakeToToggleVisibility"] == nil ){
[defaults setObject:[NSNumber numberWithBool:YES] forKey:#"kShakeToToggleVisibility"];
}
if ( [defaults objectForKey:#"kBackgroundAudio"] == nil ){
[defaults setObject:[NSNumber numberWithBool:YES] forKey:#"kBackgroundAudio"];
}
if ( [defaults objectForKey:#"kUseMyLocation"] == nil ){
[defaults setObject:[NSNumber numberWithBool:YES] forKey:#"kUseMyLocation"];
}
if ( [defaults objectForKey:#"kAttachTwitterIcon"] == nil ){
[defaults setObject:[NSNumber numberWithBool:YES] forKey:#"kAttachTwitterIcon"];
}
if ( [defaults objectForKey:#"kAttachTwitterLink"] == nil ){
[defaults setObject:[NSNumber numberWithBool:YES] forKey:#"kAttachTwitterLink"];
}
/* User chose to log out of Facebook Session, do that now. */
if ( [[defaults objectForKey:#"kLogoutFacebook"] boolValue] == YES ){
[defaults setObject:[NSNumber numberWithBool:NO] forKey:#"kLogoutFacebook"];
[self fbLogout];
}
[defaults synchronize];
Related
I want to write a simple cmdline app that will toggle the "Use all F1,F2... keys as standard function keys". I know i can use appleScript, but that shows the gui and is not nice. So how to do that from code? I tried the defaults command defaults write -g com.apple.keyboard.fnState -bool false and that does change the preferences flag when read with defaults command but not in the GUI and it is not working.
Also tried something like that:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *key = #"com.apple.keyboard.fnState";
BOOL fnState = [defaults boolForKey:key];
NSLog(#"First value of fnState: %#", fnState ? #"true" : #"false" );
if (fnState) {
[defaults setBool:NO forKey:key];
}
else{
[defaults setBool:YES forKey:key];
}
fnState = [defaults boolForKey:key];
NSLog(#"Value of fnState after toggle: %#", fnState ? #"true" : #"false" );
[NSUserDefaults resetStandardUserDefaults];
This one has proper states logged between runs, but defaults command does not see it, and the Fn key does not care either.
How should one proceed ? I know it can be done.
I have an app already in the AppStore that uses NSUserDefaults. Some of the defaults are Default settings that I go ahead and set when the app is first launched, and then the user is allowed to change them later if they wish. So, in my AppDelegate appDidFinishLaunchingWithOptions I put:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if (! [defaults boolForKey:#"notFirstRun"]) {
[defaults setBool:YES forKey:#"notFirstRun"];
[defaults setInteger:0 forKey:#"verseKey"];
[defaults synchronize];
}
The issue I am having now is I want to add some more Default settings in the NSUserDefault category, so I want to make it look like this:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if (! [defaults boolForKey:#"notFirstRun"]) {
[defaults setBool:YES forKey:#"notFirstRun"];
NSString *smalltitle = #"4";
NSString *smallarticle = #"3";
[defaults setObject:smalltitle forKey:#"Title"];
[defaults setObject:smallarticle forKey:#"Article"];
[defaults setInteger:0 forKey:#"verseKey"];
[defaults synchronize];
}
I know that this will cause an issue for those who have already downloaded the app, and are merely updating it. They will not run that code because the notFirstRun Bool has already been set to YES. Any thoughts on what I should do here?
The proper solution is to not actually populate NSUserDefaults with default values. Instead, use the registerDefaults: method.
At app startup you do:
NSUserDefaults *default = [NSUserDefaults standardUserDefaults];
[defaults registerDefaults:#{
#"Title" : #"4",
#"Article" : #"3",
#"verseKey" : #0
}];
That's it. Call this every time the app is run. These defaults are not actually persisted. The value is only returned if there isn't already an explicit value for the key. You can update these defaults all you want without affecting any existing values.
Make a new notFirstRun Boolean value (i.e. notFirstRunTwo). That will be 'NO' for existing users, too.
I suggest to do the following :
check userdefaults for stored app version if it is equal to the current or not , if not.
store the current app version and do your first launch initialization
the code
`
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *appVersion = [NSString stringWithFormat:#"%#",[[NSBundle mainBundle] objectForInfoDictionaryKey:#"CFBundleShortVersionString"]];
if (! [defaults objectForKey:appVersion ])
{
/// store the current version and then do your first run functions
[defaults setObject:[NSNumber numberWithInt:1] forKey:appVersion];
/// here do your first run
......
}`
I'm attempting to store the current level for my game in NSUserDefaults but it always returns 1 when I try to convert it to an int. Here's the test code:
[[NSUserDefaults standardUserDefaults] setInteger:34 forKey:#"Current Level"];
NSLog(#"default level raw: %#", [[NSUserDefaults standardUserDefaults] objectForKey:#"Current Level"]);
self.levelNum = [[[NSUserDefaults standardUserDefaults] objectForKey:#"Current Level"] intValue];
NSLog(#"default level num: %i", self.levelNum);
And the output:
default level raw: 34
default level num: 1
Just make sure to call synchronize on NSUSerDefaults:
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
[defaults setInteger:34 forKey:#"Current Level"];
NSLog(#"default level raw: %#", [defaults objectForKey:#"Current Level"]);
[defaults synchronize]; // Call synchronize after set
self.levelNum = [defaults integerForKey:#"Current Level"];
NSLog(#"default level num: %i", self.levelNum);
One thing about your code is that you're using "setInteger" (which is a NSInteger)
[defaults setInteger:34 forKey:#"Current Level"];
with
self.levelNum = [[[NSUserDefaults standardUserDefaults] objectForKey:#"Current Level"] intValue]
which assumes you're returning a NSNumber object from which you are reading an "int" from (not necessarily the same thing as a "NSInteger").
Instead of that second call, use:
self.levelNum = [[NSUserDefaults standardUserDefaults ] integerForKey: #"Current Level"];
"integerForKey:" is the correct method to use when you're using "setInteger:forKey:".
Oh. My. God. I'm an idiot. I forgot that I had a custom setLevelNum method defined to prevent the level from being set outside the bounds of the existing levels. Since the code above occurs before I've defined the level set, it automatically sets it to the lowest level, which is 1. Removed that and now it works. Thanks everybody for your help. At least I learned a lot about Objective-C data types :-)
[PlaySound stop];
[PlaySound prepareToPlay];
[[NSUserDefaults standardUserDefaults] synchronize];
text = [[NSUserDefaults standardUserDefaults] stringForKey:#"defaulttext"];
NSLog(#"%#",text);
BOOL loop = [prefs boolForKey:#"switch"];
NSLog(#" %d",loop);
do {
[PlaySound play];
} while (loop ==YES);
There are two major problems I am facing with this code.
1) This is a function which is called when a button is tapped... I am allocating the audio player in this function. Whenever this function is called I called the stop function on audio player yet it does not stop and two sounds play simultaneously.
2) My defaults are not registering correctly. Both the string and bool are showing nil in console.
I haves added settings bundle in my app.
Edit: Rest of the method
NSUInteger selectedRow= [SoundPicker selectedRowInComponent:0];
NSString *userchoice =[self pickerView:SoundPicker titleForRow:selectedRow forComponent:0];
NSString *soundpath = [[NSBundle mainBundle] pathForResource:userchoice ofType:#"wav"];
NSURL *fileURl = [[NSURL alloc] initFileURLWithPath:soundpath];
NSError **error = nil;
PlayFartSound = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURl error:error];
I have sorted the problem of audio player.
Can anyone please help on NSUserDefaults.
In my settings root plist I have a text field with identifier name name_preference so I put this in code:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
text = [defaults stringForKey:#"name_preference"];
NSLog(#"%# abc",text);
The log is (null) abc ? [I have set the default value to hello in plist]
How are you setting the default values in your NSUserDefaults? You say you've got the defaults in a plist, but when do you load that plist into NSUserDefaults?
To set the default NSUserDefaults values, you need to call this somewhere early in your program, ideally in somewhere like applicationDidFinishLaunching
[[NSUserDefaults standardUserDefaults] registerDefaults:defaults];
Where 'defaults' is a dictionary of default settings, possibly loaded from a plist.
when my app starts music is playing:
-(void)playBgMusic {
NSString *path = [[NSBundle mainBundle] pathForResource:#"bgmusic" ofType:#"aif"];
theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
theAudio.delegate = self;
[theAudio play]; }
but he should be able to turn the music off by pressing a button if he presses the button again the music should turn on again. i have:
-(IBAction)check {
if (isquiet == NO) {
[theAudio stop];
isquiet = YES;
defaults = [NSUserDefaults standardUserDefaults];
[defaults setBool:YES forKey:#"stringKey"];
}
else {
[self playBgMusic];
isquiet = NO;
defaults = [NSUserDefaults standardUserDefaults];
[defaults setBool:NO forKey:#"stringKey"]; } }
I think I didn't get it. Now it works in my first ViewController that I can turn the music on and off but when I go to another viewController while the music is playing, then back again and press the button, the music doesn't stop and when i press it many times the music is played a second time and overlaps.
What's still wrong?
No need to wrap it in an NSNumber, there are some convenience methods for this:
To set a BOOL, use:
[userDefaults setBool:YESorNO forKey:#"yourKey"];
To access it, use:
[userDefaults boolForKey:#"yourKey"];
[EDIT TO ANSWER YOUR ADDITIONAL QUESTION]
Not sure why you are using NSUserDefaults - it seems unnecessary for what you are trying to achieve? Here's what I would do for a button that can start/stop music:
-(IBAction)check
{
if (isQuiet)
{
// Play music
// Change the button to indicate it is playing...
} else
{
// Stop music
// Change the button to indicate it has stopped...
}
// Set your isQuiet to be the opposite of what it was when the button was clicked
isQuiet = !isQuiet;
}
Box your BOOL value to NSNumber object and add it to NSUserDefault:
NSUserDefaults *boolUserDefaults = [NSUserDefaults standardUserDefaults];
[boolUserDefaults setObject:[NSNumber numberWithBool:isquiet]
forKey:#"stringKey"];
Later you'll be able to retrieve that value as plain BOOL using -boolForKey: function in NSUserDefaults
To save:
[boolUserDefaults setObject:[NSNUmber numberWithBool:isQuiet] forKey:#"stringKey"];
When you read it back, read it as a NSNumber then do:
BOOL savedIsQuiet = [theNumberYouSaved boolValue];
Swift:
To save bool:
UserDefaults.standard.set(true, forKey: "storageKey")
To retrieve the bool:
let boolValue = UserDefaults.standard.bool(forKey: "storageKey")