I am making an app in which the user can select a song in a settings tab and have this played in a different view on demand. I want it so that this item can be stored if the user is to shut the app and reopen it another time.
I have managed to allow the user to select and store a song in with:
-(IBAction)showMediaPicker:(id)sender{
MPMediaPickerController *mediaPicker = [[MPMediaPickerController alloc] initWithMediaTypes: MPMediaTypeAny];
mediaPicker.delegate = self;
mediaPicker.allowsPickingMultipleItems = NO;
mediaPicker.prompt = #"Select Alarm Sound";
[self presentModalViewController:mediaPicker animated:YES];
}
- (void) mediaPicker: (MPMediaPickerController *) mediaPicker didPickMediaItems: (MPMediaItemCollection *) mediaItemCollection {
[self dismissModalViewControllerAnimated: YES];
settingsData.selectedSong = mediaItemCollection;//Object of type MPMediaItemCollection
but I want the user to have to do this every time they use the app.
I have tried using NSUserDefaults:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:settingsData.selectedSong forKey:#"alarmSoundKey"];
[defaults synchronize];
but get the error:
* -[NSUserDefaults setObject:forKey:]: Attempt to insert non-property value '' of class 'MPMediaItemCollection'. Note that dictionaries and arrays in property lists must also contain only property values.
What are my options please? Not really sure how to tackle this one...
SOLUTION -
I can't answer my own questions yet so I'll put it up here:
I HAVE FOUND MY OWN SOLUTION TO THIS:
First convert/encode the MPMediaItemCollection to an NSData Object and slam store it using NSUserDefaults using:
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:mediaItemCollection];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:data forKey:#"someKey"];
[defaults synchronize];
From there, you can decode and use anywhere else in your app....
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSData *data = [defaults objectForKey:#"someKey"];
MPMediaItemCollection *mediaItemCollection = [NSKeyedUnarchiver unarchiveObjectWithData:data]
Hope that is some help to someone. Spread the word, this hasn't been covered enough. Have literally been working on this problem for about 4 hours...
You can only store property list values in NSUserDefaults. Since MPMediaItemCollection conforms to NSCoding you could use an NSKeyedArchiver to store it instead.
http://developer.apple.com/library/ios/#documentation/Cocoa/Reference/Foundation/Classes/NSKeyedArchiver_Class/Reference/Reference.html#//apple_ref/doc/uid/TP40003672
You then use NSKeyedUnarchiver to read it back out of the file later.
You can also use the MPMediaItemPropertyPersistentID property. You can form a query to retrieve the item from the iPod library when your application next launches, and gracefully handle things like when the user decides to remove the song from their library.
Related
I am experiencing strange behaviour with NSUserDefaults. I am initially storing an array to the user defaults in my AppDelegate.m:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSArray *weekdayIDs = [defaults objectForKey:#"weekdayIDs"];
if (weekdayIDs == nil) {
weekdayIDs = [NSArray arrayWithObjects:#"su", #"mo", #"tu", #"we", #"th", #"fr", #"sa", nil];
[defaults setObject:weekdayIDs forKey:#"weekdayIDs"];
}
[defaults synchronize];
Now in a different view controller ContentViewController.m, I want to retrieve the array:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSArray *weekdayIDs = [defaults objectForKey:#"weekdayIDs"];
But I just get an array without objects, although its count == 7. I also used arrayForKey: but with the same result. I added a screenshot from my breakpoint.
I am regularly using NSUserDefaults, but currently I am bit stuck on this. It's probably a stupid mistake, anyone care to help?
Thank you so much!
-- Update:
I also figured it might be a problem with the init of the NSArray in the first place, but even replacing its objects with manually created NSString *dwid_su = [NSString stringWithString:#"su"]; didn't work.
Your code works perfectly.
Just, print the description of you array and you will see what you want.
Right click on weekdayIDs variable and select Print Description of weekdayIDs
or use through lldb debugger console po weekdayIDs
or NSLog(#"%#", weekdayIDs);
Here the results.
I would like to save Array/NSDictionary to NSUserDefaults but anything I try is just not working. Here is my code so please if you know how to do this, help me.
NSArray *oneArray = [NSArray arrayWithObjects:#"Radio One",nil];
NSDictionary *one = [NSDictionary dictionaryWithObject:oneArray forKey:#"Stations"];
NSArray *oneLinkArray = [NSArray arrayWithObjects:#"http://mobile.com:28000/",nil];
NSDictionary *oneLink = [NSDictionary dictionaryWithObject:oneLinkArray forKey:#"Stations"];
[data addObject:one];
[link addObject:oneLink];
The reason I need this is to put this station into favorites. So my thinking is to save these info in to NSUserDefaults and retrieve in favorites table.
Thanks and please any suggestion is welcomed and appreciated.
You can use something like this when you store everything into a dictionary
[[NSUserDefaults standardUserDefaults] setObject:link forKey:#"dictionary1"];
Or you can put everything into an array and store it like this
[[NSUserDefaults standardUserDefaults] setObject:data forKey:#"array1"];
You can access it again by using
NSDictionary * myDictionary = [[NSUserDefaults standardUserDefaults] dictionaryForKey:#"dictionary1"];
Typically adding an object into NSUserDefaults goes like this:
NSMutableDictionary *dictionaryToAdd = [[NSMutableDictionary alloc] init];
[dictionaryToAdd setObject:#"xyz" forKey:#"myKey"];
NSUserDefaults *myDefaults = [NSUserDefaults standardUserDefaults];
[myDefaults setObject:dictionaryToAdd forKey:#"someKey"];
[myDefaults synchronize];
A few things on your code above though - you're adding stuff into 'data' and 'link' but I don't see those in your code, so I'm assuming those arrays exist somewhere.
To sum it up - declare an NSUserDefaults object, set objects into it like an NSDictionary, and then synchronize it to save data.
Additional code as requested:
//You have an array named arrayToAdd that has already been created
NSUserDefaults *myDefaults = [NSUserDefaults standardUserDefaults];
[myDefaults setObject:arrayToAdd forKey:#"SomeKeyThatYouMakeUp"];
[myDefaults synchronize];
//You want to get the array out of NSUserDefaults
NSArray *mySavedArray;
NSUserDefaults *myDefaults = [NSUserDefaults standardUserDefaults];
mySavedArray = [myDefaults objectForKey:#"SomeKeyThatYouMakeUp"];
So I have an app that lets you put in a title and an author on the front page, then you hit enter and it will go into the actual features of the app. I want to save the data with NSUserDefaults, so that when they click the enter button, it saves it *AND goes into the next view. I have it setup with the storybord already to go into the next view, but when I use this code:
-(IBAction)enter:(id)sender {
titleString = [[NSString alloc] initWithFormat:[title text]];
[title setText:titleString];
NSUserDefaults *titleDefault = [NSUserDefaults standardUserDefaults];
[titleDefault setObject:titleString forKey:#"stringkey"];
authorString = [[NSString alloc] initWithFormat:[author text]];
[title setText:authorString];
NSUserDefaults *authorDefault = [NSUserDefaults standardUserDefaults];
[authorDefault setObject:authorString forKey:#"stringkey2"];
}
It will always crash when you hit the button. I have all the NSStrings defined and such, so I don't see what the problem is. I also have it loading with:
title.text = [[NSUserDefaults standardUserDefaults] objectForKey:#"stringkey"];
author.text = [[NSUserDefaults standardUserDefaults] objectForKey:#"stringkey2"];
Under the viewdidload, so can I have some help as to why this wouldn't work?
Just to optimize your -enter:method:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:title.text forKey:#"stringkey"];
[defaults setObject:author.text forKey:#"stringkey2"];
[defaults synchronize]; // this will store them instantly!
For the crash: can you please provide us with the exact crash log? Maybe your Button is linked to an unknown selector...
First, there are a few questions about this: here, here. Try searching around first, and at least let people know why the duplicate questions you found didn't work for you.
Secondly, I think you might benefit from adding a synchronize. Use this:
titleString = [[NSString alloc] initWithFormat:[title text]];
[title setText:titleString];
NSUserDefaults *titleDefault = [NSUserDefaults standardUserDefaults];
[titleDefault setObject:titleString forKey:#"stringkey"];
[titleDefault synchronize];
authorString = [[NSString alloc] initWithFormat:[author text]];
[author setText:authorString];
NSUserDefaults *authorDefault = [NSUserDefaults standardUserDefaults];
[authorDefault setObject:authorString forKey:#"stringkey2"];
[authorDefault synchronize];
I also changed the [title setText:authorString]; line to [author setText:authorString];. I do, however, think it is a bit redundant the way you are allocating the NSStrings to the value of the text fields and then setting the text back to the value of the string you created. I don't get the need. Anyway, hope this helps.
I'm trying to create an application, and in that I'm receiving some contents from net and loading into and array, if I quit and run the app again i'm losing the data. How can I store the data in the app itself. Should I use some kind of database? If so which one and how can I implement that? I need to store only some string variables.
EDIT:
My app is tabbar based app, and have two tabs. Loading the arrays in one tab and loading that array in a table in the other VC. once I load the array and move to the second tab, the table is loaded with the array. If i go back and add few more values and then if i check, the added datas is not displayed in the table. And also, when I quit the app the table lose all the values, I need to keep the values in the table, even after i quit the app. How can I do that?
here is my code:
in viewdidload:
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
[simplePlistDb setBool:YES forKey:#"isItWorking"];
[simplePlistDb setObject:alertList forKey:#"myArray"];
[simplePlistDb synchronize];
in cellforrowatindexpath:-
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
BOOL flag = [simplePlistDb boolForKey:#"isItWorking"];
if (flag)
{
NSArray *myArray = [simplePlistDb objectForKey:#"myArray"];
for (NSString *str in myArray){
NSLog(#"Str:%#", str);
[loadArray addObject:str];
}
cell.textLabel.text = [loadArray objectAtIndex:indexPath.row];
}
Thank you.
You will want to look into Core Data if you want to save a decent amount of data to the iPhone. However, if not, you can just load the items in the array into a plist and load them from there at launch.
Plist Writing: How to create a new custom property list in iPhone Applications
CoreData: http://www.raywenderlich.com/934/core-data-tutorial-getting-started
Edit--->
As Nekto said, you can also use NSUserDefaults, but I advise mainly using NSUserDefaults for simple NSStrings and integers.
I think for your purposes NSUserDefaults will be enough : NSUserDefaults Class Reference.
Examples:
// save
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
[simplePlistDb setBool:YES forKey:#"isItWorking"];
[simplePlistDb setObject:[NSArray arrayWithObjects:#"very", #"cool", nil]];
[simplePlistDb synchronize];
// restore
NSUserDefaults *simplePlistDb = [NSUserDefaults standardUserDefaults];
BOOL flag = [simplePlistDb boolForKey:#"isItWorking"];
if (flag)
{
NSArray *myArray = [simplePlistDb objectForKey:#"myArray"];
for (NSString *str in myArray)
NSLog(#"%#", str);
}
You can use NSUserDefaults in order to store your data till the time your app is installed in your device.
How to write in NSuserDefaults:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:#"yourObject1" forKey:#"correspopndingKey1"];
[defaults setObject:#"yourObject2" forKey:#"correspopndingKey2"];
[defaults synchronize];
How to read from NSuserDefaults:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *temp1 = [defaults objectForKey:#"correspopndingKey1"];
NSString *temp2 = [defaults objectForKey:#"correspopndingKey2"];
You can store NSArray in a similar way.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:objArray forKey:#"correspopndingKey"];
[defaults synchronize];
I have some data that's been stored using NSUserDefaults in one view and then being displayed in another view. The issue I'm having is that when the user changes the data and then returns to the view where the data is displayed (in a UILabel), the data that was first saved is displayed instead of the newer saved text.
I think I need to do something with viewDidAppear perhaps, so that every time the view appears the newest saved data is displayed.
here's the code that Im displaying the NSUserDefaults stored info on a UILabel:
NSString *aValue = [[NSUserDefaults standardUserDefaults] objectForKey:#"myTextFieldKey"];
NSLog(#"Value from standardUserDefaults: %#", aValue);
NSLog(#"Label: %#", myLabel);
myLabel.text = aValue;
if someone could point me in the right direction that would be great,
thanks
Put this text in
- (void) viewWillAppear:(BOOL)animated
{
[super viewWillAppear: animated];
NSString *aValue = [[NSUserDefaults standardUserDefaults] objectForKey:#"myTextFieldKey"];
NSLog(#"Value from standardUserDefaults: %#", aValue);
NSLog(#"Label: %#", myLabel);
myLabel.text = aValue;
}
And in your "edit" view in - viewWillDisappear: save changes in NSUserDefaults
When saving data to NSUserDefaults, it doesnt immediately write to the Persistent Storage. When you save data in NSUserDefaults, make sure you call:
[[NSUserDefaults standardUserDefaults] synchronize];
This way, the value(s) saved will immediately be written to Storage and each subsequent read from the UserDefaults will yield the updated value.
Do not forget the use synchronize when you set some value
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:YOUR_VALUE forKey:#"KEY_NAME"];
[defaults synchronize];
Now you can place your code in viewWillAppear method to retrieve the value from defaults, this will help you fetch the currentsaved value for your desired key.
NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
NSString* strValue = [defaults objectForKey:#"KEY_NAME"];
myLabel.text = strValue != nil ? strValue : #"No Value";
Hope it helps
In Swift we can do it following way:
To save value:
let defaults = UserDefaults.standard
defaults.set(YOUR_VALUE, forKey: "YOUR_KEY_NAME")
To get value:
let defaults = UserDefaults.standard
let data = defaults.objectForKey("YOUR_KEY_NAME")
For more details visit:
https://www.hackingwithswift.com/example-code/system/how-to-save-user-settings-using-userdefaults