I am new to iPhone programming. How do I add an NSString to an NSArray. I have thumbnail images. If I click on any one of the images I want to store imagepath in the NSArray. Same if I click on the same image I want to remove the imagepath from NSArray. (like select and deselect) Can anybody tell me how I can do this, what is the logic for that? Till now I have been doing
- (void)click
{
NSLog(#"%#",_fullsizeUrl);
array =[[NSMutableArray alloc]init];
[array addObject:_fullsizeUrl];
NSLog(#"%#",array);
}
In above code _fullsizeUrl is imagepath I am storing this in an NSMutableArray. The problem is if select any one image means Ii getting image path that is storing in NSArray. But if I select any other images it's storing the latest one previous one is removing. Can any body tell me how to do this
Thanks
Your "previous one is removing" because you are reallocating your NSMutableArray everytime you tap the thumbnail. Allocate the array outside the click method.
-(void)click
{
if ([yourAry containsObject:yourObject])
{
[yourAry removeObject:yourObject];
}
else{
[yourAry addObject:yourObject];
}
}
array =[[NSMutableArray alloc]init];
[array addObject:_fullsizeUrl];
You are creating a new array every time click is called. At the end of the method, the array has no strong references (assuming ARC, otherwise you are leaking memory) and gets deallocated.
Make your NSMutableArray a property on your class and then click should look like this:
- (void)click
{
if ([self.myArray containsObject:self.fullSizeUrl]) {
[self.myArray removeObject:self.fullSizeUrl];
} else {
[self.myArray addObject:self.fullSizeUrl];
}
}
If you are only storing unique strings in your array you could consider using NSMutableSet instead.
You can use this method and use one int variable i and increase ever time +1.
- (void)insertObject:(id)anObject atIndex:(NSUInteger)index;
Related
I want to add 'email' data to my NSMutableArray so every time the button is pushed it adds another email to the array, so I end up with an array of email addresses but can't seem to get it working.
I think my problem is I am reinitialising the array so clearing it out and maybe need to put the initialisation somewhere else..which I have tried.
The below code lets me add an address but each time the IBAction is called I think I am clearing the array, any pointers or help would be great
#property (strong, nonatomic) NSMutableArray *mutable;
#synthesize mutable;
- (IBAction)array:(id)sender {
mutable = [[NSMutableArray alloc]initWithObjects:self.person.email, nil];
[mutable addObject:self.person.email];
NSLog(#"ARRAY OF EMAILS %#",mutable);
}
You are right - you are initializing the array each time the array: method is called. You can change the code to initialize it only once:
- (IBAction)array:(id)sender {
if(!self.mutable) {
self.mutable = [[NSMutableArray alloc]initWithObjects:self.person.email, nil];
}
[self.mutable addObject:self.person.email];
}
As a side note - you don't have to use #synthesize for this property. Read "Adopting Modern Objective-C" for more details.
Did you use UIViewController? If yes then reset the array in viewDidAppear method.
If you are using the UIView, then create the custom method to reset the array and call from the parent viewController.
I don't know if what I see with a popup button populated by bindings with a value transformer is the way it's supposed to be or not -- the unusual thing I'm seeing (at least with respect to what I've seen with value transformers and table views) is that the "value" parameter in the transformedValue: method is the whole array bound to the array controller, not the individual strings in the array. When I've done this with table views, the transformer is called once for each displayed row in the table, and the "value" parameter is whatever object is bound to that row and column, not the whole array that serves as the content array for the array controller.
I have a very simple app to test this. In the app delegate there is this:
+(void)initialize {
RDTransformer *transformer = [[RDTransformer alloc] init];
[NSValueTransformer setValueTransformer:transformer forName:#"testTransformer"];
}
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
self.theData = #[#{#"name":#"William", #"age":#"24"},#{#"name":#"Thomas", #"age":#"23"},#{#"name":#"Alexander", #"age":#"64"},#{#"name":#"James", #"age":#"47"}];
}
In the RDTransformer class is this:
+ (Class)transformedValueClass {
return [NSString class];
}
+(BOOL)allowsReverseTransformation {
return NO;
}
-(id)transformedValue:(id)value {
NSLog(#"%#",value);
return value;
}
In IB, I added an NSPopupButton to the window and an array controller to the objects list. The content array of the controller is bound to App Delegate.theData, and the Content Values of the popup button is bound to Array Controller.arrangedObjects.name with the value transformer, testTransformer.
When I run the program, the log from the transformedValue: method is this:
2012-09-19 20:31:39.975 PopupBindingWithTransformer[793:303] (
)
2012-09-19 20:31:40.019 PopupBindingWithTransformer[793:303] (
William,
Thomas,
Alexander,
James
)
This doesn't seem to be other people's experience from what I can see on SO. Is there something I'm doing wrong with either the bindings or the value transformer?
Unfortunately, this is how NSPopUpButton works. The problem is not limited to that control. If you try binding an NSArrayController.contentArray to another NSArrayControllers.arrangedObject.someProperty you will get the same problem. Here is a simple workaround that I use in all my value transformers, which makes them work with both tables and popups:
You can modify your value transformer in the following way:
-(id)transformedArrayValue:(NSArray*)array
{
NSMutableArray *result = [NSMutableArray array];
for (id value in array)
[result addObject:[self transformedValue:value]];
return result;
}
-(id)transformedValue:(id)value
{
if ([value isKindOfClass:[NSArray class]])
return [self transformedArrayValue:value];
// Do your normal-case transform...
return [value lowercaseString];
}
It's not perfect but it's easy to replicate. I actually put the transformedArrayValue: in a class category so that I don't need to copy it everywhere.
I have an API provided NSArray with a bunch of content objects – we'll call this acquiredFruit – and an empty NSMutableArray called likedFruit.
I've created NSArrayControllers for both arrays and bound my TableView to acquiredFruit.arrangedObjects. The first column of the tableView is bound to arrangedObjects.name and correctly shows all the delicious fruit.
I've created a second column with a checkbox – when the user fills the box I'd like to add the fruit to my likedFruit array. Unchecking the box should remove the fruit object from the likedFruit array.
Essentially I'd like my NSTableView to join between two array controllers. I have a feeling I should be making a single separate controller for this, but I'm unsure how to approach the problem.
I should also mention that I'm aware I could iterate through my array and construct another object with the fields I need, but my goal is to do this by using bindings, if possible.
Thoughts?
I think you should use one array controller.
You can have an attribute on Fruit called liked. Now your "liked" checkbox column is connected to arrangedObjects.liked. Later, when you want to determine the set of all liked fruits, you can query your fruits array:
NSArray * likedFruits = [ allFruitsArray filteredArrayUsingPredicate:[ NSPredicate predicateWithFormat:#"liked = YES"] ] ;
If in another part of your UI you are displaying only liked fruit, you can set your array controller's filterPredicate to the predicate above to get just those fruits.
EDIT: Let's say NSFruit is provided via someone else's API. Let's use the "General Technique for Adding Properties to Someone Else's Class":
#interface NSFruit (Liking)
#property ( nonatomic ) BOOL liked ;
#end
#implementation NSFruit (Liking)
-(BOOL)liked
{
return [ objc_getAssociatedObject( self, "_abliked" ) boolValue ] ;
}
-(void)setLiked:(BOOL)b
{
objc_setAssociatedObject( self, "_abliked", [ NSNumber numberWithBool:b ], OBJC_ASSOCIATION_RETAIN_NONATOMIC ) ;
}
#end
(I've written this same code for like 100 posts recently!)
I'm not at my Xcode computer right now, so i can't test this, but it seems like you don't really need another array controller, but just another array to hold the likedFruits. I think you need to create an array of dictionaries from your acquiredFruits array that would have one key for the fruit name and another key with a bool value for whether the check box is checked --this bool would be bound to your second column. I'm not sure about the next step on how to tell the likedFruit array that it need to add a new fruit -- I think the check box could have an action method that you could use to have the likedFruit array add the object in the row where the check box was clicked.
After Edit:
Here is an example of how to do what I suggested. I take an array of fruits and turn it into an array of dictionaries (called theData) that include a key for the value of your check box (In IB the content array of the array controller is bound to theData, and the columns are bound to Array Controller.arrangedObjects.fruitName and Array Controller.arrangedObjects.isLiked). checkChanged is an IBAction connected to the check box (but note the sender is actually the table view), and I use the value of the check box to determine whether to add a fruit to likedFruits or delete one. I put one more method, connected to a button just to check the values in likedFruits.
#implementation AppDelegate
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
self.theData = [NSMutableArray array];
self.likedFruit =[NSMutableArray array];
NSArray *acquiredFruits = #[#"Apple",#"Orange",#"Pear",#"Peach"];
for (NSString *aFruit in acquiredFruits) {
NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:aFruit,#"fruitName",[NSNumber numberWithBool:NO],#"isLiked", nil];
[self.theData addObject:[dict mutableCopy]];
}
self.theData = _theData;
// NSLog(#"%#",self.theData);
}
-(IBAction)checkChanged:(NSTableView *)sender { //connected to the button cell in the table view (but sender is the table view)
NSString *theFruit = [[self.controller.arrangedObjects objectAtIndex:sender.clickedRow ] valueForKey:#"fruitName"];
BOOL doWeLikeIt = [[[self.controller.arrangedObjects objectAtIndex:sender.clickedRow] valueForKey:#"isLiked"] boolValue];
if (doWeLikeIt) {
[self.likedFruit addObject:theFruit];
}else{
[self.likedFruit removeObject:theFruit];
}
}
-(IBAction)logLikedFruits:(id)sender {
NSLog(#"%#",self.likedFruit);
}
I would like to make a history list in my app. I have surfed and looked at many questions here, but so far I haven´t found the answer to my question.
My codes:
-(void)searchBarTextDidEndEditing:(UISearchBar *)searchBar
{
NSLog (#"search bar text did end editing!");
NSString *bookmarked = mySearchBar.text;
NSMutableArray *bookmarkl = [[NSMutableArray alloc] init];
int i;
for (i = 0; i < [bookmarkl count]; i ++)
{
[bookmarkl addObject:bookmarked];
}
for (NSString *sa in bookmarkl);
NSLog (#"whole array: %#", bookmarkl);
}
But all I get is one string at a time. What is wrong?
I want to add a new string to the mutable array, how should I do this?
You are creating a new list every time the function is called. You should add bookmarkl to your class as a property and only create it once during initialization. If you want the history to persist when your app is closed you will also want to write the data to a file. You can use [NSMutableArray arrayWithContentsOfFile] to load the history and writeToFile to save it.
I have just started to jump into the realm of Objective-C and am slowly getting it all. I have been working on unarchiving a file that was a NSMutableArray and then initializing in my model with that array. The array is filled with various NSMutableDicationary's. From what I have seen it will add those dictionaries as non-mutable, so I went ahead and copied the regular and put them in a mutable and remove the old one. This solution seems to work for every instance except the very first.
I am at a loss as to why it would work for all but the first.
Here is how I am initializing it all
-(id) initWithList:(NSMutableArray *)savedList
{
self = [super init];
if (self)
{
int size=0;
serverList=[[NSMutableArray alloc] initWithArray:savedList copyItems:YES];
size=[serverList count];
for(int i=0;i<size;i++)
{
loginList=[NSMutableDictionary dictionaryWithDictionary:[serverList objectAtIndex:i]];
[serverList addObject:loginList];
[serverList removeObjectAtIndex:i];
}
}
return self;
}
Here is the code that is throwing the error, The value is being read off of a checkbox in a tableview and passed here to change the value.
-(void)setMount:(int)row value:(NSNumber*)boolAsNumber
{
[[serverList objectAtIndex:row] setObject:boolAsNumber forKey:#"mountshare"];
}
Here is the error that it shows when I try and change the first element
2010-12-01 13:38:54.445 Network Share[35992:a0f] *** -[NSCFDictionary setObject:forKey:]: mutating method sent to immutable object
Thanks for your help. If there is a better way please let me know.
This loop code is wrong:
size=[serverList count];
for(int i=0;i<size;i++)
{
loginList=[NSMutableDictionary dictionaryWithDictionary:[serverList objectAtIndex:i]];
[serverList addObject:loginList];
[serverList removeObjectAtIndex:i];
}
When you remove an object, the array is renumbered. After you've processed the 1st object at index 0, the original 2nd object is becoming the 1st object at index 0, but i is now set to index 1, which is where the original 3rd object is! This means you're only processing alternate items from the original array, and the 2nd, 4th, etc items never get swapped, and that's why you get the errors you're seeing.
One way to solve this would be to replace the "i" in the objectAtIndex: and removeObjectAtIndex: calls with "0", so you're always taking items off the front of the array.
The alternate solution would be to create a separate newServerList array and insert your new objects into that. At the end of the loop, release the old serverList and set the variable to point to newServerList.
Your indexes are messed up. As soon as you remove the object at index 0, the next one will take it's place and you will never replace that, because you then carry on with index 1.
{immutable0, immutable1}
i = 0:
addObject:
{immutable0, immutable1, mutable0}
removeObjectAtIndex:
{immutable1, mutable0}
i = 1:
addObject:
{immutable0, mutable0, mutable02}
removeObjectAtIndex:
{immutable0, mutable02}
--> still got the immutable there. Remember to never remove objects from a mutable array you are looping through at the same time.
You could condense the code a bit:
NSMutableArray *serverList = [NSMutableArray arrayWithCapacity:[savedList count]];
for (NSDictionary *dictionary in savedList)
{
mutable = [dictionary mutableCopy];
[serverList addObject:mutable];
[mutable release];
}
Unrelated to your problem: the argument is obviously wrong (NSMutableArray), if you expect an immutable array there; and if you create your serverList that way, there is no need for a deep copy (copyItems:YES).