I am trying to save lessons in a day (from text-fields) into an array so that I can save them, and later display them on a new view.
My current code:
//monLessons = Monday's lessons
NSMutableArray *monLessons;
monLessons = [NSMutableArray arrayWithObjects: self.mon1.text, self.mon2.text, self.mon3.text, self.mon4.text, self.mon5.text, self.mon6.text, nil];
Cheers!
If it is just this one NSMutableArray that you want to access from multiple classes - NSUserDefaults would be the easiest and cleanest solution.
Example
So save the NSMutableArray:
[[NSUserDefaults standardUserDefaults]setObject:YOUR ARRAY forKey:#"MondayLessons"];
Now NSUserDefaults returns a immutable copy of the a array when you ask for it - you will need to return it like this:
NSMutableArray *yourArray = [[[NSUserDefaults standardUserDefaults]objectForKey:#"MondayLessons"] mutableCopy];
This way you get an NSMutableArray back and not an NSArray
Edit 2
I forgot to add:
Before you close your application or move to a new ViewController - you need to save the data to NSUserDefaults So please call - [[NSUserDefaults standardUserDefaults]synchronize];
Anytime you want to save. If you don't call this line of code - when you ask NSUserDefaults for your Array - it will be nil. You need to do this every time you make a change to the array you're saving.
Related
I am making a game using cocos2d-iphone and would like to make a screen with best previous scores. I have two scenes. In the MainScene I made a global variable for storing a score, that is obviously changing during the game; one mutable array and one simple array that will be a duplicate for the mutable one:
NSInteger _scoreValue;
NSMutableArray *_scoresMutable;
NSArray *_scores;
In the same class, when game ends, I add new score to the mutable array, make a static duplicate and save it in NSUserDefaults:
[_scoresMutable addObject:#(_scoreValue)];
_scores=[NSArray arrayWithArray:_scoresMutable];
[[NSUserDefaults standardUserDefaults] setObject:_scores forKey:#"gameScores"];
Then, in other class of scene with scores called bestscores(I don't know how is better, but it was easier for me to make just a new scene, because I am using SpriteBuilder) I import MainScene.h just in case and make a label.
At the moment I am trying to get all scores from NSUserDefaults, to sort it and to show second biggest value. But it always shows 0 (label is empty by default). So, how to make that's all right?
- (void)didLoadFromCCB {
NSSet *numberSet = [NSSet setWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:#"gameScores"]];
NSArray *sortedNumbers = [[numberSet allObjects] sortedArrayUsingDescriptors:#[[NSSortDescriptor sortDescriptorWithKey:#"self" ascending:NO] ]];
NSNumber *secondHighest;
if ([sortedNumbers count] > 1){
secondHighest = sortedNumbers[1];
}
[_secondBiggestLabel setString:[NSString stringWithFormat:#"%ld",(long)secondHighest]];
}
`
EDIT : synchronize didn't help. Maybe I need to write something else to get access to NSUserDefaults from another one class?
When you set the object you have to follow it with a call to synchronize. That will actually save it.
[[NSUserDefaults standardUserDefaults] synchronize];
Are you sure you've initialized that '_scoresMutable' array?
Also, if the code from the below section is ran on a separate launch than when the first section of code is ran, it's possible you're terminating the app before the defaults can write to disk. Call 'synchronize' on the NSUserDefaults instance to fix that.
I'v run into such problem. I need to update the values in my NSArray. And don't know a way to do it. Here's my array
NSArray *arrayWithInfo = [[NSArray alloc] initWithObjects:AMLocalizedString(#"Status", nil),AMLocalizedString(#"Call", nil),AMLocalizedString(#"Location", nil),AMLocalizedString(#"Control", nil),AMLocalizedString(#"Sim", nil),AMLocalizedString(#"Object", nil),AMLocalizedString(#"Info", nil),nil];
self.dataArray = arrayWithInfo;
[arrayWithInfo release];
To be more specific I have tableview initialized with this array. There is a possibility for user to use different localized strings, so I have to update it. By using [tableview reloadData]; i'v got the table to update, but the values in NSArray stay the same as they were initialized in first place.
So how to make array look up at the strings once again and get their new values?
Use NSMutableArray instead of NSArray
NSMutableArray (and all other classes with Mutable in the name) can be modified.
You should be using an NSMutableArray. Doing so will allow you to change its values after instantiation.
Your array doesn't need to be mutable here as the array seems to be all or nothing. You dont mention the requirement to delete some objects and not others. NSMutableArray isn't needed. You want to write a lazy loading getter method for the array which reinstantiates it if the array doesnt exist.
-(NSArray *)dataArray{
if (_dataArray){
return _dataArray;
}
_dataArray = NSArray *arrayWithInfo = [[NSArray alloc] initWithObjects:AMLocalizedString(#"Status", nil),AMLocalizedString(#"Call", nil),AMLocalizedString(#"Location", nil),AMLocalizedString(#"Control", nil),AMLocalizedString(#"Sim", nil),AMLocalizedString(#"Object", nil),AMLocalizedString(#"Info", nil),nil];
return _dataArray;
}
Then when you want to reload the tableView
self.dataArray = nil;
[tableView reloadData];
this destroys the old array, forcing it to be remade but with the new localisation.
EDIT:
The issue is the array isn't storing the statement AMLocalizedString(#"Status", nil) its storing the result of that statement, which is the localised string itself. There is no way to make the array re-evaluate that statement without either re-creating the whole array again or using an NSMutableArray and changing all the objects. The lazy loading getter method is more in the objective-c style.
You need to use the NSMutableArray. The NSArray is immutable.
Hello :)
How can i save objects, but not overwrite in Objective C,
i tried NSUserDefaults but when i add object, it will overwrite !
how can i prevent this, because i am trying to create a favorites in my app or bookmarks,
but i don't know how to save those objects i am trying to save.
This is when i am trying to save.
NSUserDefaults *favorite = [NSUserDefaults standardUserDefaults];
[favorite setObject:saveTip forKey:#"saveTipFavorite"];
[favorite synchronize];
But i overwrite every time i push add to favorite button in my app !
And i don't want it to overwrite, but make a new object and append it.
I hope you understand me :)
It is overwriting because there can only be one object per key, and you are changing it each time. What you want to do, is store an array instead of a single object, and set that as a key in your user defaults.
Initialization:
NSMutableArray *objectArray;
NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];
NSArray *oldSavedArray = [currentDefaults objectForKey:#"savedArray"];
if (oldSavedArray != nil)
objectArray = [[NSMutableArray alloc] initWithArray:oldSavedArray];
else
objectArray = [[NSMutableArray alloc] init];
Notice we are converting from NSArray to NSMutableArray because the user defaults can only store the immutable (NSArray) version.
Then to add an item:
[objectArray addObject:whatever];
[currentDefaults setObject:objectArray forKey:#"savedArray"];
If this is something you will be doing a lot (tons of data), you may consider using Core Data instead, it will be faster. NSUserDefaults is not really meant for storing heavy data.
The object you save can be an array. Create an array to save the tips and make that the object given to NSUserDefaults.
NSUserDefaults is fine for simple stuff, but if you want your App to handle significant amount of data, you will want to start using CoreData.
http://developer.apple.com/library/mac/#documentation/cocoa/Conceptual/CoreData/cdProgrammingGuide.html
Not only will this solve your saving problem, it will also make it easier to manipulate your data.
I am trying to store user input text (in this case a book title) into an array so that I can output it in a table view in another xib.
I'm getting stuck trying to store the "bookTitle.text" info into my "userinfoArray". I know it probably has a simple solution and I know how to do it in C++ but not in Objective-C. Any tips, links etc. would be great.
NSMutableArray *userinfoArray = [[NSMutableArray alloc]init];
NSString *tempString = [[NSString alloc]initWithString:[bookTitle text]];
[userinfoArray addObject:tempString];
you can then access it later with:
[userinfoArray objectAtIndex:0];
NSMutableArray is very flexible. with addObject:object you can add as many things as you want, remove them with removeObjectAtIndex:index.
more here: NSMutableArray Class Reference
alternatively if you know what size your array will have you can use a normal NSArray: NSArray Class Reference which will work similar
sebastian
Try
userinfoArray = [NSArray arrayWithObject:[bookTitle text]];
Or if you want to create a longer array with more objetcs then
userinfoArray = [NSArray arrayWithObjects:[bookTitle text], secondObject, thirdObject, nil];
If you want to add or remove objects later then you may want to use NSMutableArray instead.
If this does not answer your question, then please try to be a bit more specific about your problem.
I'm working with the MKMapView and I'm using some arrays to handle the title of points on the map
NSString *mapTitles = #"title1^^title2^^title3^^title4";//this data changes between views
NSArray * titlesArray = [mapTitles componentsSeparatedByString: #"^^"];
NSMutableArray * maptitle = [NSMutableArray arrayWithCapacity:[titlesArray count]];
[maptitle addObjectsFromArray:titlesArray];
When a user navigates to another page I want to clear the NSMutableArray so that when they come back to the map I can refresh it with new data. However as the NSMutableArray is getting populated by an NSArray which I can't clear, how do I ensure that the NSMutableArray only gets populated by new data as opposed to something that the NSArray may have kept from the previous view?.
Is it simply a case of releasing the NSArray, for example in viewWillDisappear?
Thanks
You can still clear the mutable array itself:
[mapTitle removeAllObjects];
You shouldn't release the titlesArray because it's autoreleased.