I'm very new to objective-c so be easy :-) I have a container object, "Data", who has a number of NSMutableArrays.
Data.h
#interface Data : NSObject{
NSMutableArray *one;
NSMutableArray *two;
}
#property (nonatomic, retain) NSMutableArray *one;
#end
and would like to pass it to a load method in which case it will update each corresponding array in the Data class.
Parser.h
+ (Parser *)load:(Data*) store;
Parser.m
+ (Parser *)load:(Data *) store {
...
[store.one addObject:name.stringValue];
}
But no matter what I do the string in "name.stringValue" doesn't get appended to the array. Is there something I'm missing when passing in the "Store" data object to the parse method? Let me know if I should provide more details but I feel this covers the issue.
Check in your implementation of Data that you are properly initializing the mutable arrays - here is a simple example below given your Data interface:
#import "Data.h"
#implementation Data
{
#pragma mark - Properties
- (NSMutableArray *)one
{
if (!_one) {
_one = [[NSMutableArray alloc] init];
}
return _one;
}
- (NSMutableArray *)two
{
if (!_two) {
_two = [[NSMutableArray alloc] init];
}
return _two;
}
}
Use one = [NSMutableArray array]; before you start using it. This will create an empty mutable array.
Related
I have this class with an NSMutableArray of custom Cocos2d objects implementing the NSCoding protocol.
#interface PlayerData : NSObject <NSCoding> {
}
#property (readwrite, nonatomic) NSMutableArray *levelsStars; //Where levelsStars is filled with objects conforming to the NSCoding protocol.
The objects are of type LevelData, which inherits from CCNode (a Cocos2d class) and conforms to the NSCoding protocol.
#interface LevelData : CCNode <NSCoding>
Here is the implementation of the protocol in PlayerData. In order to encode and decode the NSMutableArray of custom Cocos2d objects, which conform to NSCoding objects:
-(void) encodeWithCoder:(NSCoder *)aCoder
{
[aCoder encodeObject:[NSKeyedArchiver archivedDataWithRootObject:levelsStars] forKey:kLevelsStars];
}
-(id) initWithCoder:(NSCoder *)aDecoder
{
self = [super init];
if (self) {
//Reading arrays:
NSData * dataRepresentingLevelStars = [aDecoder decodeObjectForKey:kLevelsStars];
if (dataRepresentingLevelStars!=nil) {
NSArray * oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:dataRepresentingLevelStars];
if (dataRepresentingLevelStars!=nil) {
levelsStars = [NSMutableArray arrayWithArray:oldSavedArray];
}
else
{
levelsStars = [[NSMutableArray array] initWithCapacity:10];
}
}
}
return self;
}
Is this approach correct? I based it on this question / answer.
EDIT: I thought I will add some more details on my use case
My users can choose among different characters, each characters corresponds to a PlayerData object which I plan to store in a different file appending the user's game center id (id-character1.archive, id-character2.archive etc..).
I do save progress of the characters in the object (e.g. score, life) including the NSMutableArray custom array of Cocos2d-objects (in my real case I do have 5 different arrays containing 20/30 objects each).
In your main init method for the PlayerData object you want to do the unarchive:
- (id)init {
self = [super init];
if (self) {
self.levelsStars = [NSKeyedUnarchiver unarchiveObjectWithFile:pathToArchive];
if (self.levelsStars == nil) self.levelsStars = [NSMutableArray array];
}
}
This will then call initWithCoder: on each of your objects that was in the array. And pull them back into a mutable array.
You will want to have some method for saving your data though, again on your PlayerData object:
- (void)applicationDidEnterBackground:(NSNotification *)notification {
[NSKeyedArchiver archiveRootObject:self.levelsStars toFile:pathToArchive];
}
This will call encodeWithCoder: on each of the objects in the array and write them out to a file.
I am making a NSObjectClass that has a method in it that returns self.
This is what it looks like roughtly
storageclass.h
// storageclass vars go here
- (storageclass)assignData:(NSDictionary *)dictionary;
storageclass.m
//#synthesise everything
- (storageclass)assignData:(NSDictionary *)dictionary {
//assign values from dictionary to correct var types (i.e. NSString, Int, BOOL)
//example
Side = [dictionary valueForKey:#"Side"];
return self;
}
Then what I want to do is use this class by passing a NSDictionary var through its method to return a object of type storageclass that I can then use to access the vars using dot notation.
this is how I am trying to access this class at the moment
accessorViewController.h
storageclass *store;
#property (strong, nonatomic) storageclass *store;
accessorViewController.m
#synthesize store;
- (void)getstoreready {
[store assignData:someDictionary];
nslog(#"%#", store);
}
this NSLog returns nothing and in the debugger all of stores class vars are empty showing nothing has been assigned. I am 100% positive the dictionary vars being used in the assignData method have the correct valueForKey values.
I think it has something to do with how I am using it here [store assignData:someDictionary]; how do i catch the turned data so I can use it?
any help would be appreciated.
The store object is never initialized so it will be nil thats obvious isn't it. Initialize the store object first, then call its instance methods onto it. And by doing that, you'll have a storageclass object which is properly assigned with some dictionary already.
And if you want to have a storageclass object like your code shows, you should make your (storageclass)assignData:(NSDictionary *)dictionary method a class method instead of an instance method by putting a + sign
+(storageclass*)assignData:(NSDictionary *)dictionary;
Then properly initialize it and assign the data (dictionary to variables) accordingly and return it to the caller. For example :-
in .m file
+(storageclass*)assignData:(NSDictionary *)dictionary{
storageclass *test = [[storageclass alloc] init];
if (test) {
test.someDict = dictionary;
}
return test;
}
Then use this class method in your view controller as
- (void)getstoreready {
store = [storageClass assignData:someDictionary];
nslog(#"%#", store);
}
Also Do follow the naming convention for classes and instances. A class's name must start with a capital letter only and the opposite for any class instances.
In User.h
#interface User : NSObject
#property (nonatomic, copy) NSString *name;
- (id)initWithDictionary:(NSDictionary *)dictionary;
+ (NSArray *)usersFromArray:(NSArray *)array;
#end
In User.m
- (id)initWithDictionary:(NSDictionary *)dictionary
{
self = [super init];
if (self) {
if (dictionary)
{
self.name = dictionary[#"kUserName"];
}
}
return self;
}
+ (NSArray *)usersFromArray:(NSArray *)array
{
NSMutableArray *users = [NSMutableArray array];
for (NSDictionary *dict in array) {
User *user = [[User alloc]initWithDictionary:dict];
[users addObject:user];
}
NSSortDescriptor *descriptor = [NSSortDescriptor sortDescriptorWithKey:#"name"
ascending:YES];
return [users sortedArrayUsingDescriptors:#[descriptor]];
}
In ViewController.m
import "User.h"
self.currentArray = [User usersFromArray:array];
I'm new to iphone app development and I'm stuck on this problem I'm having with the app I'm trying to develop.
I have a datacontroller for populating a tableview. I created it using this tutorial:
About Creating Your Second iOS App
I'm trying to pass an array from one of my viewcontrollers that was created from a JSON response.
Here is some code from my viewcontroller.h that needs to pass the array:
#interface ViewController : UIViewController
#property (nonatomic, retain) DataController *Data;
#property (nonatomic, retain) NSMutableArray *array;
#end
viewcontroller.m:
#import "DataController.h"
[Data setMasterList: self.array];
DataController.h:
#interface DataController : NSObject
#property (nonatomic, strong) NSMutableArray *masterList;
- (void)setMasterList:(NSMutableArray *)newList;
#end
DataController.m
#import "LoginViewController.h"
- (void)setMasterList:(NSMutableArray *)newList {
if (_masterList != newList) {
_masterList = [newList mutableCopy];
NSLog("List: %#", newList);
}
}
The NSLog message never shows up in the console and the array is nil.
Any help is appreciated.
Thanks.
EDIT:
Here's the updated viewcontroller.m:
Data = [[DataController alloc] init];
[Data setMasterList: self.array];
The datacontroller.m:
- (void)setMasterList:(NSMutableArray *)newList {
if (_masterList != newList) {
_masterList = [newList mutableCopy];
NSLog("List: %#", self.masterList);
}
}
- (NSUInteger)countOfList {
NSLog("List: %#", self.masterList);
return [self.masterList count];
}
The first nslog inside setMasterList returns the correct array values, but the second nslog inside countOfList returns null. The list always returns null anywhere outside of setMasterList. Is it because I'm creating a new instance of the DataController? If so, how else could I pass the array to the datacontroller.
As in first comment Till have suggested, Data must be initialized before calling setMasterList. Such As:
Data = [[DataController alloc] init];
[Data setMasterList: self.array];
In my application i have an custom NSObject, which contains 2 mutable Arrays.
I need to save this custom NSOBject into a core data entity, but i have no real idea how i can accomplish that...
After some searching, i found out, that the best way would be to convert the nsobject to nsdata and save it in an transformable field of the entity... but i m not sure how to do that.
can someone help me?
heres to code for my custom object:
MeasureData.h
#interface MeasureData : NSObject{
}
#property (nonatomic, strong) NSMutableArray *questionsData;
#property (nonatomic, strong) NSMutableArray *answersData;
- (id) init;
#end
MeasureData.m
#import "MeasureData.h"
#implementation MeasureData
#synthesize questionsData;
#synthesize answersData;
#pragma mark -
#pragma mark int
- (id)init
{
self = [super init];
// Initalize questions array (width data from plist)
questionsData = self.makeQuestionsArray;
// NSLog(#"loaded questions array: %#",questionsData); // debug
// Initalize answers array
answersData = self.makeAnswersArray;
// NSLog(#"loaded answers array: %#",answersData); // debug
return self;
}
-(NSMutableArray *)makeQuestionsArray
{
// Initalize questions array (width data from plist)
NSString *path = [[NSBundle mainBundle] pathForResource:
#"questions.list" ofType:#"plist"];
NSMutableArray *questions = [NSMutableArray arrayWithContentsOfFile:path];
/*
[questionsData insertObject:(NSString *)string atIndex:0];
*/
return questions;
}
-(NSMutableArray *)makeAnswersArray
{
// Initalize answers array
NSMutableArray *answers = [NSMutableArray arrayWithCapacity:0];
return answers;
}
-(id)initWithCoder:(NSCoder *)decoder {
if ((self=[super init])) {
questionsData = [decoder decodeObjectForKey:#"questionsData"];
answersData = [decoder decodeObjectForKey:#"answersData"];
}
return self;
}
-(void)encodeWithCoder:(NSCoder *)encoder {
[encoder encodeObject:questionsData forKey:#"questionsData"];
[encoder encodeObject:questionsData forKey:#"questionsData"];
}
#end
According to the first comment, i implemented the encoder/coder functions for my custom class. And tried to archive and encode it (i m new to ios, so it could be completly wrong) - but it dont work... can someone tell me whats wrong?
heres the encoding (which dont work XD):
NSMutableData *dataToSave = (NSMutableData *)self.measureData;
NSKeyedArchiver *archiverForData = [[NSKeyedArchiver alloc] initForWritingWithMutableData:dataToSave];
[archiverForData encodeObject:dataToSave forKey:#"dataToSave"];
[archiverForData finishEncoding];
//
//theMeasure is the CoreData Entity
theMeasure.result = dataToSave;
In outline:
create a NSMutableData
create a NSKeyedArchiver with initForWritingWithMutableData over your data
serialize your arrays / objects / whatever you need (that implements NSCoding) with encode... methods of NSCoder
create a managed object with a BLOB (binary data) type field
write your encoded data from the mutable data to this field of the managed object.
In my answer to this question you can find some useful links: NSCoding VS Core data
I have an NSMutableArray object (retained, synthesized as all) that is initiated just fine and I can easily add objects to it using the addObject: method. But if I want to replace an object at a certain index with a new one in that NSMutableArray, it doesn't work.
For example:
ClassA.h:
#interface ClassA : NSObject {
NSMutableArray *list;
}
#property (nonatomic, copy, readwrite) NSMutableArray *list;
#end
ClassA.m:
#import "ClassA.h"
#implementation ClassA
#synthesize list;
- (id)init
{
[super init];
NSMutableArray *localList = [[NSMutableArray alloc] init];
self.list = localList;
[localList release];
//Add initial data
[list addObject:#"Hello "];
[list addObject:#"World"];
}
// Custom set accessor to ensure the new list is mutable
- (void)setList:(NSMutableArray *)newList
{
if (list != newList)
{
[list release];
list = [newList mutableCopy];
}
}
-(void)updateTitle:(NSString *)newTitle:(NSString *)theIndex
{
int i = [theIndex intValue]-1;
[self.list replaceObjectAtIndex:i withObject:newTitle];
NSLog((NSString *)[self.list objectAtIndex:i]); // gives the correct output
}
However, the change remains true only inside the method. from any other method, the
NSLog((NSString *)[self.list objectAtIndex:i]);
gives the same old value.
How can I actually get the old object replaced with the new one at a specific index so that the change can be noticed from within any other method as well.
I even modified the method like this, but the result is the same:
-(void)updateTitle:(NSString *)newTitle:(NSString *)theIndex
{
int i = [theIndex intValue]-1;
NSMutableArray *localList = [[NSMutableArray alloc] init];
localList = [localList mutableCopy];
for(int j = 0; j < [list count]; j++)
{
if(j == i)
{
[localList addObject:newTitle];
NSLog(#"j == 1");
NSLog([NSString stringWithFormat:#"%d", j]);
}
else
{
[localList addObject:(NSString *)[self.list objectAtIndex:j]];
}
}
[self.list release];
//self.list = [localList mutableCopy];
[self setList:localList];
[localList release];
}
Please help out guys :)
This does the trick:
[myMutableArray replaceObjectAtIndex:index withObject:newObject];
OK, there are a few bits of confusion here.
You don't need to take a mutableCopy of a newly created NSMutableArray to make it mutable. It's already mutable -- the clue is in the name. You only need to do that in the setter if you want the property to have copy semantics (which you've set, and may have good reason for, of course). But you certainly wouldn't need to do it as shown in your updated updateTitle code, and doing so leaks localList.
Also, you're mixing together property access via self.list and direct use of list in the same method. This is not invalid, but it's bad practice, because it means whatever other stuff the accessor methods do is being randomly bypassed. It's common for properties like this to do everything through self except in the accessors themselves, or in dealloc, and possibly in init (opinions seem to differ on this), where you would access the ivar directly.
Also, never call [self.list release] -- the property accessor doesn't give its caller ownership. Doing this will end in tears, mark my words.
None of this answers the real question, which is why is your change disappearing. The original updateTitle code does not explain this as far as I can see -- it should work. So I suspect that somewhere else you are calling self.list = theOriginalList and hence undoing your change.
Update:
Just for the sake of argument, I'm going to post what I think the code you posted is probably meant to look like. I've preserved your use of a string to pass the index to updateTitle, but I'd like to point out that doing it this way is wrong. It's a number, you should pass it as such. Even if the number comes from a text field or something, that's the caller's concern; the class interface should specify a number. Similarly the apparent change from 1-based to 0-based indexing. Please do not do this sort of thing implicitly, it is a recipe for weeping and gnashing of teeth.
ClassA.h:
#import <Cocoa/Cocoa.h>
#interface ClassA : NSObject
{
NSMutableArray* list;
}
- (void) setList:(NSMutableArray*)newList;
- (void) updateTitle:(NSString*)newTitle forIndex:(NSString*)theIndex;
#property (nonatomic, copy, readwrite) NSMutableArray* list;
#end
ClassA.m:
#import "ClassA.h"
#implementation ClassA
#synthesize list;
- (id) init
{
if ( self = [super init] )
{
list = [[NSMutableArray alloc] init];
[list addObject:#"Hello "];
[list addObject:#"World"];
}
return self;
}
- (void) setList:(NSMutableArray*) newList
{
if ( list != newList )
{
[list release];
list = [newList mutableCopy];
}
}
- (void) updateTitle:(NSString*)newTitle forIndex:(NSString*)theIndex
{
int i = [theIndex intValue] - 1;
[self.list replaceObjectAtIndex:i withObject:newTitle];
}
- (void) dealloc
{
[list release];
[super dealloc];
}
#end
This cleans up various issues, but note that updateTitle is mostly the same. If you drop all this in and the change still doesn't survive, you are definitely resetting list somewhere.
A more straight answer would be:
self.list[i] = newTitle;
This just works like
[self.list replaceObjectAtIndex:i withObject:newTitle];
Look at this line:
#property (nonatomic, copy, readwrite) NSMutableArray *list;
The copy means that whenever you access self.list, you don't get the "_list" instance variable of your object, but a copy of that list. If you write [self.list replaceObjectAtIndex... ] you replace an object in that copy of your list; the original _list is unchanged. Just use
#property (nonatomic, strong, readwrite) NSMutableArray *list;
And to avoid confusion, remove the "list" instance variable and the #synthesize statement, then use _list to access the instance variable.
For Swift you could try:
//if you have indexPath
self.readArray.removeAtIndex((indexPath?.row)!)
self.readArray.insert(tempDict, atIndex: (indexPath?.row)!)
//tempDict is NSDictionary object.
Finally Got Some Perfect Code,
let DuplicateArray: NSArray = array
let DuplicateMutableArray: NSMutableArray = []
DuplicateMutableArray.addObjectsFromArray(DuplicateArray as [AnyObject])
var dic = (DuplicateMutableArray[0] as! [NSObject : AnyObject])
dic["is_married"] = "false"
DuplicateMutableArray[self.SelectedIndexPath] = dic
array = []
array = (DuplicateMutableArray.copy() as? NSArray)!
//Output Will Be Like
array = [
{
"name": "Kavin",
"Age": 25,
"is_married": "false"
},
{
"name": "Kumar",
"Age": 25,
"is_married": "false"
}
]