Below I have some code which should return an array, the response from the server happens in a block:
- (NSMutableArray *)getArray
{
NSMutableDictionary* params =[NSMutableDictionary dictionaryWithObjectsAndKeys:
#"pending", #"command",
#"2" , #"userID",
nil];
[[API sharedInstance] commandWithParams:params
onCompletion:^(NSDictionary *json) {
//result returned
if ([json objectForKey:#"error"]==nil) {
NSMutableArray *res = [[NSMutableArray alloc] init];
[res addObject:#"1234"];
RETURN HERE
} else {
//error
[UIAlertView title:#"Error" withMessage:[json objectForKey:#"error"]];
}
}];
}
After parsing the data and creating an array I want to return the array I have created for the getArray method call. So far, after hours of trying I have not had any luck, even with trying some suggestions from previous questions on stackoverflow. Any help would be appreciated.
pass the block as a param to the function
- (NSMutableArray *)getArray:(void (^)(NSArray *))block {}
And then replace the RETURN HERE with block(res);
I'd create a method in somewhere in the class let's say - (void)arrayFetched:(NSArray *)fetchedArray.
Then you modify your code like this:
//...
if ([json objectForKey:#"error"]==nil) {
__weak NSMutableArray *res = [[NSMutableArray alloc] init];
[res addObject:#"1234"];
dispatch_async(dispatch_get_main_queue(), ^{
[self arrayFetched:[res copy]];
});
//...
and then do want you want with the array in the arrayFetched: method.
Related
As I have a requirement to add similar objects into the array, I have created new dictionary in such a way.
NSMutableDictionary* existingStepDict = [[[arrayForSteps objectAtIndex:0] mutableCopy] autorelease];
[arrayForSteps addObject:existingStepDict];
[existingStepDict release];
Now, what happens here is that later when I change something in any one of the dictionary, the other one also gets updated. I require both these dictionaries to behave independently.
For that I went through Deep-copy of dictionaries whose code is like this.
NSMutableDictionary* existingStepDict = [[[arrayForSteps objectAtIndex:0] mutableCopy] autorelease];
NSMutableDictionary* destination = [NSMutableDictionary dictionaryWithCapacity:0];
NSDictionary *deepCopy = [[NSDictionary alloc] initWithDictionary:existingStepDict copyItems: YES];
if (deepCopy) {
[destination addEntriesFromDictionary: deepCopy];
[deepCopy release];
}
//add Properties array to Steps Dictionary
[arrayForSteps addObject:destination];
But this too didn't reflect the difference. I know I am making some minor mistake here.
But could some one help me getting my result?
Thanks a lot!
There's an easy way to get a full deepcopy of an NSDictionary o NSArray using the NSCoding (serialization) protocol.
- (id) deepCopy:(id)mutableObject
{
NSData *buffer = [NSKeyedArchiver archivedDataWithRootObject:mutableObject];
return [NSKeyedUnarchiver unarchiveObjectWithData: buffer];
}
In this way you can duplicate any object plus all the obects it contains in a single step.
when I need a mutable deep copy of a NSDictionary I create a Category with this method:
- (NSMutableDictionary *)mutableDeepCopy
{
NSMutableDictionary *returnDict = [[NSMutableDictionary alloc] initWithCapacity:[self count]];
NSArray *keys = [self allKeys];
for (id key in keys) {
id oneValue = [self valueForKey:key];
id oneCopy = nil;
if ([oneValue respondsToSelector:#selector(mutableDeepCopy)]) {
oneCopy = [oneValue mutableDeepCopy];
} else if ([oneValue respondsToSelector:#selector(mutableCopy)]) {
oneCopy = [oneValue mutableCopy];
}
if (oneCopy == nil) {
oneCopy = [oneValue copy];
}
[returnDict setValue:oneCopy forKey:key];
}
return returnDict;
}
EDIT
and searching the web I found this, I haven't tested
NSMutableDictionary *mutableCopy = (NSMutableDictionary *)CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (CFDictionaryRef)originalDictionary, kCFPropertyListMutableContainers);
I'm trying to create an NSDictionary full of arrays in the implementation file of my model but my code hasn't worked yet. I want to create arrays that are lists of types of dogs and cats and then add those arrays to a dictionary with keys called DOG and CAT. Here is my code:
#implementation wordDictionary
#synthesize catList = _catList;
#synthesize dogList = _dogList;
#synthesize standardDictionary =_standardDictionary;
- (void)setCatList:(NSMutableArray *)catList
{
self.catList = [NSMutableArray arrayWithObjects:#"lion", #"puma", #"snow leopard", nil];
}
- (void)setDogList:(NSMutableArray *)dogList
{
self.dogList = [NSMutableArray arrayWithObjects:#"pit bull", #"pug", #"chihuahua", nil];
}
-(void)setStandardDictionary:(NSMutableDictionary *)standardDictionary
{
[self.standardDictionary setObject: _catList forKey:#"CAT"];
[self.standardDictionary setObject: _dogList forKey:#"DOG"];
}
- (NSString*)selectKey
{
NSInteger keyCount = [[self.standardDictionary allKeys] count];
NSInteger randomKeyIndex = arc4random() % keyCount;
NSString *randomKey = [[self.standardDictionary allKeys] objectAtIndex:randomKeyIndex];
return randomKey;
}
#end
This code is the model. The model is hooked up to my view controller such that when a user taps a button, the NSString returned from randomKey is displayed in a label on the screen. So the text will read either CAT or DOG. Here's the code for that:
- (IBAction)changeGreeting:(UIButton*)sender {
NSString *chosenKey = [self.dictionary selectKey];
NSString *labelText = [[NSString alloc] initWithFormat:#"%#", chosenKey];
self.label.text = labelText;
}
Unfortunately when I tap the button on the simulator I get an error message saying: Thread 1:EXC_ARITHMETIC (code=EXC_1386_DIV, subcode=0x0) at NSInteger randomKeyIndex = arc4random() % keyCount; and it appears that I'm getting it because neither my NSArray nor my NSDictionary have any objects inside of them.
Does anyone have any idea why my NSArray and NSDictionary haven't been populated?
Thanks very much.
The simple answer is that there isn't any code here that calls the methods to set the arrays or dictionary.
But the real underlying issue is that there are a couple of bad 'patterns' going on here that you should fix:
In your setter methods (setCatList:, setDogList:, setStandardDictionary:) you're not setting the properties in question to the values that are passed in. For example, you should be setting catList to the passed in "catList" variable.
- (void)setCatList:(NSMutableArray *)catList
{
if (_catList != catList) {
[_catList release];
_catList = [catList retain];
}
}
Then you should have some kind of "setup" happening, usually in a method in the view controller like viewDidLoad:
[wordDictionary setCatList:[NSMutableArray arrayWithObjects:#"lion", #"puma", #"snow leopard", nil]];
// and more for the other two setters
Alternately, you can set these default values in the init for the wordDictionary class:
- (id)init {
self = [super init];
if (self) {
[self setCatList:[NSMutableArray arrayWithObjects:#"lion", #"puma", #"snow leopard", nil]];
}
return self;
}
The former is better in most cases, but you may have a good reason to pre-populate your model for all instances of the class.
Assuming you called setCatList:, setDogList: and setStandardDictionary: before. Probably that causing is this :
NSString *chosenKey = [self.dictionary selectKey];
change into this :
NSString *chosenKey = [self selectKey];
UPDATE
I'm trying to make your life easier. no need to create your object if you don't need the most.
- (NSMutableArray*)getCatList
{
return [NSMutableArray arrayWithObjects:#"lion", #"puma", #"snow leopard", nil];
}
- (NSMutableArray*)getDogList
{
return [NSMutableArray arrayWithObjects:#"pit bull", #"pug", #"chihuahua", nil];
}
-(NSMutableDictionary*)getStandardDictionary
{
NSMutableDictionary *standardDictionary = [NSMutableDictionary new];
[standardDictionary setObject:[self getCatList] forKey:#"CAT"];
[standardDictionary setObject:[self getDogList] forKey:#"DOG"];
return [standardDictionary autorelease];
}
- (NSString*)selectKey
{
NSMutableDictionary *standardDictionary = [self getStandardDictionary];
NSInteger keyCount = [[standardDictionary allKeys] count];
NSInteger randomKeyIndex = arc4random() % keyCount;
NSString *randomKey = [[standardDictionary allKeys] objectAtIndex:randomKeyIndex];
return randomKey;
}
- (IBAction)changeGreeting:(UIButton*)sender {
// NSString *chosenKey = [self selectKey];
//NSString *labelText = [[NSString alloc] initWithFormat:#"%#", chosenKey];
self.label.text = [self selectKey]; //no need to convert it to NSString again
}
Two things to consider:
I don't see you calling these:
setCatList:(NSMutableArray*)catList;
setDogList:(NSMutableArray*)dogList;
You use self.catList and self.dogList, but neither of those are synthesized, instead you have beatList and meList synthesized
Change the synthesizes to the catList and dogList, and make sure you call the set list methods, and then you should make some progress.
-(id) initWithData:(NSString *)lastName: (NSString *)firstName{
self->firstname = firstName;
self->lastname = lastName;
return self;
}
-(void) printData {
NSLog(#"firstname: %#", firstname);
NSLog(#"lastname: %#", lastname);
}
so whenever I create a new object using the above init function. And Add objects to a NSMutableArray, using the addObject function.
NSMutableArray *objectArray = [[NSMutableArray alloc] init];
CustomObject *tempObject = [[CustomObject alloc] initWithData: #"smith": #"john"];
CustomObject *tempObjectb = [[CustomObject alloc] initWithData: #"brown": #"william"];
[objectArray addObject:tempObject];
[objectArray addObject:tempObjectb];
[[objectArray objectAtIndex:0] printData];
[[objectArray objectAtIndex:1] printData];
objects at index 1, and 0 always equal the whichever object was added to the array last.
This also happens if I use a for loop, or have more than 2 objects, all values when printed, turn to the values of the last added object to the objectArray. Let me know if there is any information that I am missing.
Is there something that I am missing?
Fix your initWithData:lastName: implementation as following:
-(id) initWithData:(NSString *)lastName: (NSString *)firstName
{
self = [super init];
if ( nil != self ) {
self->firstname = [firstName retain];
self->lastname = [lastName retain];
}
return self;
}
I have a SOAP service and I generated classes and functions on SudzC.com.
So I'm using the soap functions they generated, it returns an NSMutableArray with objects that are inherited by my custom class(which is generated by them, too).
So far everything's good. My values are getting into the array and I could see any property of any object with one condition: Only inside of the function that's handling the service.
Just to make it clear, here is the code:
- (void)viewDidLoad
{
SDZGeneratedWebService* service = [SDZGeneratedWebService service];
service.logging = YES;
[service callMyData:self action:#selector(callMyDataHandler:) dataId: 1];
[super viewDidLoad];
}
- (void) callMyDataHandler: (id) value {
// Handle errors
if([value isKindOfClass:[NSError class]]) {
NSLog(#"%#", value);
return;
}
// Handle faults
if([value isKindOfClass:[SoapFault class]]) {
NSLog(#"%#", value);
return;
}
// Do something with the NSMutableArray* result
NSMutableArray *result = (NSMutableArray *)value;
MyCustomClass *myObject = [result objectAtIndex:0];
NSLog(#"%#", myObject.myProperty); //Works Great
}
Like I said, so far everything's perfect. But I need to use the data outside of this function.
So in my .h file, I created an array like NSMutableArray *myDataArray;
When I intend to copy the result array to myDataArray, it copies the objects(I can see that the myDataArray.count value is equal to result array's) but all the objects are "out of scope". So I cannot use them.
I also tried to copy all objects by indexes in a for loop, nope, the objects are getting their values, but when I "addObject" to myDataArray, same, out of scope.
What is wrong here? Can't I generate an array of a custom class this way?
Edit: The code I'm generating myDataArray:
myDataArray = [[NSMutableArray alloc] init];
[myDataArray removeAllObjects];
for (int i=0; i<((NSMutableArray *)result).count; i++) {
MyCustomClass *myObject = [result objectAtIndex:i];
[myDataArray addObject:myObject];
[myObject release];
}
[self.tableView reloadData];
} //(End of callMyDataHandler function)
I before tried this way, too:
[myDataArray removeAllObjects];
duyurular = [result mutableCopy];
} //(End of callMyDataHandler function)
You can copy objects from one array to another using this method:
NSArray *source;
NSArray *dst = [[NSArray alloc] initWithArray:source];
In your code you should remove line: [myObject release]; and I would better call [((NSMutableArray *)result) count] rather then using dot notation.
I want a table of state-names for debug/trace messages as I develop my custom gesture. What is wrong with this declaration and its usage?
static NSDictionary *dictStateNames = nil;
#implementation MyCustomGesture
#synthesize state;
+(void)initStateNames {
if (dictStateNames == nil) {
dictStateNames = [NSDictionary dictionaryWithObjectsAndKeys:
#"StateBegan", [NSNumber numberWithInt:UIGestureRecognizerStateBegan],
#"StateCancelled", [NSNumber numberWithInt:UIGestureRecognizerStateCancelled],
#"StateChanged", [NSNumber numberWithInt:UIGestureRecognizerStateChanged],
#"StateEnded", [NSNumber numberWithInt:UIGestureRecognizerStateEnded],
#"StateFailed", [NSNumber numberWithInt:UIGestureRecognizerStateFailed],
#"StatePossible", [NSNumber numberWithInt:UIGestureRecognizerStatePossible],
#"StateRecognized", [NSNumber numberWithInt:UIGestureRecognizerStateRecognized],
nil];
}
}
-(id) init {
self = [super init];
if (self) {
[MyCustomGesture initStateNames];
state = UIGestureRecognizerStatePossible;
}
return self;
}
-(id) initWithTarget:(id)target action:(SEL)action {
self = [super initWithTarget:target action:action];
if (self) {
[MyCustomGesture initStateNames];
state = UIGestureRecognizerStatePossible;
}
return self;
}
+(NSString*) stateName: (UIGestureRecognizerState) state {
NSString *retName = [dictStateNames objectForKey:[NSNumber numberWithInt:state]];
if (retName == nil) {
return [NSString stringWithFormat:#"Unknown state (%#)", state];
} else {
return retName;
}
}
-(NSString*) currentStateName {
return [MyCustomGesture stateName:state];
}
-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"%s (%#): %#", __FUNCTION__, [self currentStateName], event);
}
When you store a reference to an object in a static variable, you need to ensure that it doesn't get deallocated. So you can either send it a retain message, or create with alloc instead of a convenience creation method. For example:
dictStateNames = [[NSDictionary dictionaryWithObjectsAndKeys:
// List of objects and keys...
nil] retain];
or this...
dictStateNames = [NSDictionary alloc] initWithObjectsAndKeys:
// List of objects and keys...
nil];
Also, you can coalesce your stateNames getter and the initialization code into a single method, so you'll typically see Objective-C developers write a method like this:
+ (NSDictionary *)stateNames
{
static NSDictionary *stateNames;
if (stateNames == nil) {
stateNames = [NSDictionary alloc] initWithObjectsAndKeys:
// List of objects and keys...
nil];
}
return stateNames;
}
That way, there's no need to call it in an instance method (which would be wrong anyway, since a new dictionary would be created each time an instance is initialized, and unless you handled it differently, the previous one would be leaked).
On another (unrelated) note, consider rewriting your init method as follows:
- (id)init
{
return [self initWithTarget:nil action:NULL];
}
[NSDictionary dictionaryWithObjectsAndKeys] takes an object first followed by its key (as the method name suggests), which seems a bit backward but there it is.