I'm grouping my UserDefault keys by specific prefixes.
e.g.
[NSUserDefaults standardUserDefaults] setInteger: 1 forKey: #"prefix1_someText_Key"]
[NSUserDefaults standardUserDefaults] setInteger: 2 forKey: #"prefix2_someText_Key"]
[NSUserDefaults standardUserDefaults] setInteger: 3 forKey: #"prefix4_someText_Key"]
//.....
Now, I'd like to find all the keys, that start with e.g. "prefix", and load them into an array. is there a way for doing that (programmatically)?
You could use the underlying NSDictionary to find the suitable keys:
NSString *myPrefix = #"prefix";
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *dict = [defaults dictionaryRepresentation];
NSMutableArray *keysWithPrefix = [NSMutableArray array]
for (NSString *key in dict.keyEnumerator) {
if ([key hasPrefix: myPrefix]) {
[keysWithPrefix addObject: key];
}
}
// now keysWithPrefix contains all matching keys
UPDATE
For debugging reasons you could add a log to see what keys are being dropped:
for (NSString *key in dict.keyEnumerator) {
if ([key hasPrefix: myPrefix]) {
[keysWithPrefix addObject: key];
} else {
NSLog(#"Dropping key %#", key);
}
}
Related
This question already has answers here:
Easy way to see saved NSUserDefaults?
(24 answers)
Closed 9 years ago.
I would like to print all values I saved via NSUserDefaults without supplying a specific Key.
Something like printing all values in an array using for loop. Is there a way to do so?
Objective C
all values:
NSLog(#"%#", [[[NSUserDefaults standardUserDefaults] dictionaryRepresentation] allValues]);
all keys:
NSLog(#"%#", [[[NSUserDefaults standardUserDefaults] dictionaryRepresentation] allKeys]);
all keys and values:
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] dictionaryRepresentation]);
using for:
NSArray *keys = [[[NSUserDefaults standardUserDefaults] dictionaryRepresentation] allKeys];
for(NSString* key in keys){
// your code here
NSLog(#"value: %# forKey: %#",[[NSUserDefaults standardUserDefaults] valueForKey:key],key);
}
Swift
all values:
print(UserDefaults.standard.dictionaryRepresentation().values)
all keys:
print(UserDefaults.standard.dictionaryRepresentation().keys)
all keys and values:
print(UserDefaults.standard.dictionaryRepresentation())
You can use:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *defaultAsDic = [defaults dictionaryRepresentation];
NSArray *keyArr = [defaultAsDic allKeys];
for (NSString *key in keyArr)
{
NSLog(#"key [%#] => Value [%#]",key,[defaultAsDic valueForKey:key]);
}
Print only keys
NSLog(#"%#", [[[NSUserDefaults standardUserDefaults] dictionaryRepresentation] allKeys]);
Keys and Values
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] dictionaryRepresentation]);
You can log all of the contents available to your app using:
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] dictionaryRepresentation]);
I have a button which on click I store the index of the current quotes into an array.
The problem is that it is overwriting the same object. How can I change it with different object of the NSNumber to store in the NSMutableArray?
[someButton setImage:[UIImage imageNamed:#"add_favoritegold.png"] forState:UIControlStateHighlighted];
NSUserDefaults *favoriteQuotes = [NSUserDefaults standardUserDefaults];
NSMutableArray *ListOfIndex= [[NSMutableArray alloc] init];
//Want to change with diffrent objecy
**NSNumber* Wrapped = [NSNumber numberWithInt:index];**
[ListOfIndex addObject:Wrapped];
int xOut = [[ListOfIndex lastObject] intValue];
NSLog(#"%d",xOut);
[favoriteQuotes setObject:ListOfIndex forKey:#"Indexes"];
Try this
- (void)saveFavouriteQuoteIndex:(NSUInteger)index
{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *savedQuoteIndexes = [[defaults objectForKey:#"Indexes"]mutableCopy];
if (!savedQuoteIndexes) {
savedQuoteIndexes = [NSMutableArray array];
}
NSNumber *indexNumber = #(index);
if (![savedQuoteIndexes containsObject:indexNumber]) {
[savedQuoteIndexes addObject:indexNumber];
[defaults setObject:savedQuoteIndexes forKey:#"Indexes"];
[defaults synchronize];
}
}
You are saving ListOfIndex with key as Indexes.
So, for the next whatever value, it will replace previous value having key Indexes.
EDIT:
Read the array
NSArray *readArray=favoriteQuotes[#"Indexes"];
Add your new value into this same array.
I am trying to implement "Add to Favorites" functionality using NSUserDefaults. So far I have written following code.
- (void)favouriteButtonClicked:(id)sender
{
favselected = !favselected; // favselected is BOOL property
MyAppDelegate *appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
NSString* viewname = #"custom";
if(favselected) {
[favButton setBackgroundImage:[UIImage imageNamed:#"selected.png"] forState:UIControlStateNormal];
[appDelegate addTOFavourites:self.ViewID viewType:self.ViewType];
} else {
[favButton setBackgroundImage:[UIImage imageNamed:#"unselected.png"] forState:UIControlStateNormal];
[appDelegate removeFromFavourites:self.ViewID viewType:self.ViewType];
}
}
It is working fine as long as my application is running but when I killed my application, I am losing all my stored values so when next time view loaded, in viewload isAddedToFavorites method returns false. Is there anyway to preserve my values? Am I missing something?
if([appDelegate isAddedToFavorites:self.ViewID]) {
[favButton setBackgroundImage:[UIImage imageNamed:#"selected.png"] forState:UIControlStateNormal];
favselected = YES;
} else {
[favButton setBackgroundImage:[UIImage imageNamed:#"unselected.png"] forState:UIControlStateNormal];
favselected = NO;
}
Edit:
I tried using NSMutableDictionary as I have to add multiple key-values but following method always display Count=0 even after adding object to dictionary. Any help would be really appreciated. Thank you.
-(BOOL)isAddedToFavorites:(NSString*)viewID {
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *favourites = [[standardUserDefaults objectForKey:kFavouriteItemsKey] mutableCopy];
if(favourites && [[favourites objectForKey:kFavouriteItemsKey] objectForKey:viewID])
return YES;
return NO;
}
-(void)addToFavourites:(NSString*)viewID viewType:(NSString*)viewType {
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *dict = [[standardUserDefaults objectForKey:kFavouriteItemsKey] mutableCopy];
if(standardUserDefaults) {
if(![dict objectForKey:viewID])
[dict setObject:viewType forKey:viewID]; // It is coming here but still count zero!
NSLog(#"count = %d", [dict count]);
[standardUserDefaults setObject:dict forKey:kFavouriteItemsKey]; // Always dict remains null with 0 objects in it
[standardUserDefaults synchronize];
[dict release];
}
}
-(void)removeFromFavourites:(NSString*)viewID viewType:(NSString*)viewType {
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *dict = [[standardUserDefaults objectForKey:kFavouriteItemsKey] mutableCopy];
if(standardUserDefaults) {
if ([dict objectForKey:viewID])
[dict removeObjectForKey:viewID];
[standardUserDefaults setObject:dict forKey:kFavouriteItemsKey];
[standardUserDefaults synchronize];
[dict release];
}
}
Thanks.
NSUserDefaults is actually used to store values permanently, in fact if you create any Settings for your program they will be saved as NSUserDefaults.
I think the problem is that you are not saving it with the same key you are retrieving. Try saving like this:
//To save
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:appDefaults forKey:kFavouriteItemsKey];
[[NSUserDefaults standardUserDefaults] synchronize];
//To retrieve
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
NSMutableDictionary *favourites = [[standardUserDefaults objectForKey:kFavouriteItemsKey] mutableCopy];
For the dictionary try:
NSDictionary *myDictionary= [[NSUserDefaults standardUserDefaults] objectForKey:kFavouriteItemsKey];
// Create a mutable dictionary to replace the old immutable dictionary
NSMutableDictionary *myMutableDictionary= [NSMutableDictionary dictionaryWithCapacity:[myDictionary count]+1];
// transfer the old dictionary into the new dictionary
[myMutableDictionaryaddEntriesFromDictionary:myDictionary];
// Now add the data
[myMutableDictionary setObject:myObject forKey:myKey];
I'm sorry for my bad english but i'm trying to explain with best words.
I have some problem when i'm trying to insert an NSMutableArray in NSUserDefaults ([NSUserDefaults setObject:forKey:]: Attempt to insert non-property value ')
My code to insert the array is as follows:
-(void)saveToUserDefaults:(NSMutableArray*)myArray
{
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
NSArray *array = [[NSArray alloc ] initWithArray:myArray];
if (standardUserDefaults)
{
[standardUserDefaults setObject:array forKey:#"MyArray"];
[standardUserDefaults synchronize];
}
}
My code to retrieve the array:
-(NSMutableArray*)retrieveFromUserDefaults
{
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *val = [[NSMutableArray alloc]init];
if (standardUserDefaults)
val = [NSMutableArray arrayWithArray:[standardUserDefaults arrayForKey:#"MyArray"]];
return val;
}
and in my code :
NSMutableArray :
series = [[NSMutableArray alloc]initWithObjects:nil];
//add some object inf my array...
Save my NSMutableArray :
[self saveToUserDefaults:series];
Retrieve my NSMutableArray :
series = [self retrieveFromUserDefaults];
I think it's not the best way to do this, so if anyone have ideas , it'll be helpful for me.
Thanks for reading.
Tommy
Only immutable NSArrays can be placed into defaults. Rather than placing a NSMutableArray there, convert to regular array using [NSArray arrayWithArray:] and place that one into defaults.
For retrieval, retrieve an NSArray and then use [NSMutableArray arrayWithArray:].
You can use following method to get the mutable object from immutable. It's not optimized and only implemented for NSArray and NSDictionary.
+ (id) GetMutable:(id)input {
id result;
if ([input superclass] == [NSArray class] || [input superclass] == [NSMutableArray class]) {
result = [[NSMutableArray alloc] initWithArray:input copyItems:YES];
for (int i = 0; i < [(NSMutableArray*)result count]; i++) {
[(NSMutableArray*)result replaceObjectAtIndex:i withObject:[Globals GetMutable:[(NSMutableArray*)result objectAtIndex:i]]];
}
} else if ([input superclass] == [NSDictionary class] || [input superclass] == [NSMutableDictionary class]) {
result = [[NSMutableDictionary alloc] initWithDictionary:input copyItems:YES];
NSArray *keys=[(NSMutableDictionary*)result allKeys];
for (int i = 0; i < keys.count; i++) {
[(NSMutableDictionary*)result setObject:[Globals GetMutable:[(NSMutableDictionary*)result objectForKey:[keys objectAtIndex:i]]] forKey:[keys objectAtIndex:i]];
}
}
else {
return input;
}
return result;
}
I hope this tutorial helps, who expect answer for this question.
-(void)saveToUserDefaults:(NSString*)myServerName uname:(NSString*)myUserName
pass:(NSString*)myPassword
{
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
if (standardUserDefaults) {
[standardUserDefaults setObject:myServerName forKey:#"ServerKey"];
[standardUserDefaults setObject:myUserName forKey:#"UserNameKey"];
[standardUserDefaults setObject:myPassword forKey:#"PasswordKey"];
[standardUserDefaults synchronize];
}
}
-(NSArray*)retrieveFromUserDefaults
{
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
NSString *serverName = nil;
NSString *userName = nil;
NSString *password = nil;
if (standardUserDefaults)
serverName = [standardUserDefaults objectForKey:#"ServerKey"];
userName = [standardUserDefaults objectForKey:#"UserNameKey"];
password = [standardUserDefaults objectForKey:#"PasswordKey"];
NSArray* credentials = [NSArray arrayWithObjects:serverName,userName,password, nil];
return credentials;
}
To Pass values
[self saveToUserDefaults:serverVariable uname:usernameVariable pass:passVariable];
To get Values
NSArray *result=[self retrieveFromUserDefaults];
Happy coding!!!
The contents of your array can only by plist valid objects: (NSString, NSNumber, NSDate, NSData, NSArray, or NSDictionary objects).
See documentation for NSUserDefaults setObject:forKey: and What is a Property List?
Your code needs a lot of clean up. Here is the simple and correct way to access standard user defaults:
The value you pass to your save method does not need to be mutable, although it can be. But since you are not mutating it inside your method, there's no need for it to be mutable. It just has to be not nil, which you'll check before saving:
-(void)saveToUserDefaults:(NSArray*)myArray
{
if (myArray) {
NSUserDefaults *myDefaults = [NSUserDefaults standardUserDefaults];
myDefaults[#"myArray"] = myArray;
}
}
Standard user defaults only returns non-mutable objects, which you can convert to a mutable copy using the "mutableCopy" method:
-(NSMutableArray*)retrieveFromUserDefaults
{
NSUserDefaults *myDefaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *val = [[NSMutableArray alloc] init];
val = [myDefaults[#"MyArray"] mutableCopy];
return val;
}
I want to store a float value into NSUserDefaults.
I also need to check that the float value exists..if not I need to assign some value in it.
and retrieve it...for the above I have the below code but it gives me an error.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if ([defaults boolForKey:#"HANDWRITING_SIZE_SLIDER"] == YES) {
self.sizeSlider.value = 10.0;
} else {
self.sizeSlider.value = [[NSUserDefaults standardUserDefaults] floatForKey:#"HANDWRITING_SIZE_SLIDER"]];
}
Thanks for any help
Use the NSNumber class for this and store it via the setObject:forKey: method so you can check if it exists.
I'd also suggest the usage of constants as keys:
#define HANDWRITING_SIZE_SLIDER #"HSS"
Your code should be along these lines:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
if ([defaults objectForKey:HANDWRITING_SIZE_SLIDER] == nil) {
//doesn't exist in NSUserDefaults, set to default value...
self.sizeSlider.value = 10.0;
} else {
self.sizeSlider.value = [[defaults objectForKey:HANDWRITING_SIZE_SLIDER] floatValue];
}
Somewhere else in your app, you'd set the value in NSUserDefaults like this:
float sizeSliderValue = ...
[[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithFloat:sizeSliderValue] forKey:HANDWRITING_SIZE_SLIDER];
Try this code:
-(IBAction)sliderAction:(id)sender
{
float sliderValue = [sender floatValue];
[[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithFloat:sliderValue] forKey:#"keySliderValue"];
NSLog(#"%#",[[NSUserDefaults standardUserDefaults] objectForKey:#"keySliderValue"]);
}