I have been working on this problem for close to 4 days now.
I am at the point where I think its not so much a problem with my code, but the structure of my application that is causing the issue.
I am trying to implement protocols and delegates to get an array from one NSObject(class) to a ViewController.
my code is pretty much line by line copied from this tutorial the only differences are in the face I have ARC turned on so have had to replace (nonatomic, retain) to (strong) and have not used dealloc :)
so with that being said its still not passing the data back to the viewcontroller. (highly annoying) I have tried dozens of different combinations of solutions that I have had help with and nothing has worked. This has lead me to believe that maybe there is an error in the structure of my application or the way things have been initialized etc, which I will attempt to explain now.
When my viewcontroller with tableview loads the viewdidload method called the delegate of my parser class, then once the first cell of the tableview has loaded it called my connection class and tells it to download some data from the server.
Inside my connection class I use NSURLConnection delegates from the apple library, in the delegate method connectionDidFinishLoading the data that has been downloaded is passed over to my parser class (however this is where i think its going wrong because i declare the object again.. which i think is where things are going amiss)
this is how I call my parser class from my connection class.
parserClass *myparser = [[EngineResponses alloc] init];
[myparser ReciveResponse:receivedData];
then once the data is in my parser class it gets parsed and then I try to pass the data across to my viewcontroller.. but its never accessing that delegate method that I set up.
Hopefully this is where the problem is because I just dont know where else I am going wrong.
what do you think?
UPDATE: heres my code -
ViewController.h
#import "EngineResponses.h" //delegates & protocols
interface SearchViewController : UITableViewController <PassParsedData> {
//delegates to parser class
EngineResponses *engineResponses;
//..
ViewController.m
#import "EngineResponses.h"
//this is where I set up the delegate/protocol for the parser class
- (void)viewDidLoad
{
[super viewDidLoad];
//..
engineResponses = [[EngineResponses alloc] init];
[engineResponses setMydelegate:self];
//..
}
//this is where i set up and call the connection class
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
//..
if(indexPath.section == 0){
//..
if (indexPath.row == 0){
EngineRequests *engineRequests = [[EngineRequests alloc] init];
[engineRequests initalizePacketVariables:0 startCode:#"myReg" activationCode:#"myAct" methodName:#"GetStuff"];
//..
}
#pragma - Reciver methods
- (void)sendArray:(NSArray *)array
{
ICMfgFilterArray = array;
[self.tableView reloadData];
}
EngineRequests.m
//connection delegates etc..
//then I pass the data from the connection delegates over to the parser class
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
EngineResponses *engineResponses = [[EngineResponses alloc] init];
[engineResponses ReciveResponse:receivedData];
}
EngineResponses.h
#protocol PassParsedData
- (void)sendArray:(NSArray *)array;
#end
//..
id <PassParsedData> mydelegate;
//..
#property (strong) id <PassParsedData> mydelegate;
EngineResponses.m
- (void)parserDidEndDocument:(NSXMLParser *)parser
{
//..
[[self mydelegate]sendArray:filteredArray];
}
1
Allright. I will re-do it based on your updated code. To make it easy I copy your code and do the amendments.
ViewController.h
#import "EngineResponses.h" //delegates & protocols
interface SearchViewController : UITableViewController <PassParsedData> {
//delegates to parser class
EngineResponses *engineResponses;
EngineRequests *engineRequests;
//..
Explanation:
You are using ARC. If you define the pointer locally, as you did before, and to not
retain it - which you can't because of ARC - then it will be released directly after its
creation. You will have to keep at least one reference to the object.
Bare in mind that ARC means Automatic Reference Counting. As soon as there is no
reference to an object it will be released.
This proposal with the engineRequests object defined here only works while you
submit only one request at a time. If you have several requests, i.e. for more than one cell or
whatver, then you may go for a mutable array or mutable dictionary where you keep the requests while you use them.
ViewController.m
#import "EngineResponses.h"
//this is where I set up the delegate/protocol for the parser class
- (void)viewDidLoad
{
[super viewDidLoad];
//..
engineResponses = [[EngineResponses alloc] init];
[engineResponses setMydelegate:self];
engineRequests = [[EngineRequests alloc] init]; // Use instance variable instead of local variable
[engineRequests setEnineResponses:engineResponses];
//..
}
//this is where i set up and call the connection class
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
//..
if(indexPath.section == 0){
//..
if (indexPath.row == 0){
[engineRequests initalizePacketVariables:0 startCode:#"myReg" activationCode:#"myAct" methodName:#"GetStuff"];
//..
}
#pragma - Reciver methods
- (void)sendArray:(NSArray *)array
{
ICMfgFilterArray = array;
[self.tableView reloadData];
}
Explanation: The engineRequets is now an instance varaible and should not be re-defined locally.
You could define a variable of the same name locally which would hide the instance variable. I think
in that case you get a compiler warning but that will work and will most probably confuse you.
Again, if you use more than one request at a time then this solution will not work!
EngineRequests.h
EngineResponses *engineResponses;
EngineRequests.m
#synthesize engineResponses;
//connection delegates etc..
//then I pass the data from the connection delegates over to the parser class
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
//EngineResponses *engineResponses = [[EngineResponses alloc] init]; //This Object has already been created!
[engineResponses ReciveResponse:receivedData];
}
Explanation: Here, too, the reference to EngineResponses is now an instance variable, not a locally defined one. The object will not be newly created but it references to that very object that was created in the view controller. That is the one EngineResponses that 'knows' its view controller object and can therefore pass back the parsed data.
EngineResponses.h
#protocol PassParsedData
- (void)sendArray:(NSArray *)array;
#end
//..
id <PassParsedData> mydelegate;
//..
#property (strong) id <PassParsedData> mydelegate;
EngineResponses.m
- (void)parserDidEndDocument:(NSXMLParser *)parser
{
//..
[[self mydelegate]sendArray:filteredArray];
}
... give it a try :)
Always check for nil objects. Sending a message to a nil object will do nothing and your app will continue. I bet this is the problem since you are locally allocing all over the place. Why dont you make the receivedata method a static method instead since it looks like you dont need these classes for more than a few moments for some calculations and parsing. Then nil objects wont be a factor.
Related
I am working on a splitView application for my iPad. I have implemented a UIButton called as Upload. On clicking on it, a UITableView appears inside a UIPoverController. On clicking on any of the contents, I want to display some respective site in my UIwebView in UIDetailView. For this I have implemented a delegate method protocol. I have used the following lines of code in UploadTableViewController.h file::
#protocol UploadTableViewDelegate <NSObject>
#required
- (void)selected:(NSString *)his;
#end
#interface UploadSpaceTableViewController : UITableViewController{
id<UploadSpaceTableViewDelegate> delegate;
}
#property (retain) id delegate;
#end
In the corresponding .m file I have used the following lines of code ::
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if (delegate != nil) {
NSString *hisSelected = [keys objectAtIndex:indexPath.row];
NSLog(#"%# lolwa", hisSelected);
[delegate selected:hisSelected];
}
}
in the .m file of class where I have implemented the function Selected, the code is ::
- (void)selected:(NSString *)Key {
NSLog(#"hello");
[self.UploadSpaceTableViewPopover dismissPopoverAnimated:YES];
}
-(IBAction)uploadpressed:(id)sender{
Upload.delegate = self;
self.Upload = [[UploadSpaceTableViewController alloc]
initWithStyle:UITableViewStylePlain];
self.UploadTableViewPopover = [[UIPopoverController alloc]
initWithContentViewController:UploadSpace];
[self.UploadTableViewPopover presentPopoverFromBarButtonItem:sender
permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
}
However, I am unable to get hello (written in the function Selected) NSLogged in gdb. This is the first time that I am using this delegate method protocol. I am unable to sort this out. Can someone help me out ? Thanks and regards.
[delegate keySelected:hisKeySelected]; is your first problem. You don't declare a delegate method named -keySelected:, you declare a delegate method named -Selected:.
Your second problem is the fact that you are most definitely not the delegate of your table view. In order for a delegate method like -didSelectRowAtIndexPath: to be called, you must be the table's delegate.
PS, don't begin instances, or method names, with an uppercase letter. In ObjC, uppercase letters indicate a class.
EDIT: this is what your UploadSpaceTableViewController header should look like:
#protocol UploadTableViewDelegate <NSObject>
#required
- (void)selected:(NSString *)his;
#end
#interface UploadSpaceTableViewController : UITableViewController<UITableViewDataSource, UITableViewDelegate>
#property (nonatomic, assign) id <UploadSpaceTableViewDelegate>delegate; //delegates are weak!!!
#end
And the .m, I will skip a lot of the unnecessary stuff:
-(void)viewDidLoad {
[self.tableView setDelegate:self];
[self.tableView setDataSource:self];
}
//other code
Furthermore, your delegate is declared retain, which is an absolutel No-No in ObjC. Declare is weak if using ARC, or assign if not.
You are also producing a nil delegate in in your -uploadPressed: method by setting it before you explicitly own or initialize the object. Here's how it should look:
self.Upload = [[UploadSpaceTableViewController alloc]initWithStyle:UITableViewStylePlain];
Upload.delegate = self;
Delegation works like this
declare a protocol - you have done this
declare a delegate property - you have done this
In the class which you want to be the delegate say it conforms to the protocoll
#interface MyClass : MySuperClass <UploadTableViewDelegate>
set the delegate property so the delegate class can get the delegate messages
uploadSpaceTVC.delegate = self;
call the delegate methods in your non delegate class (UploadSpaceTableViewController)
[self.delegate selected:#"test"];
this is probably simple but I'm stuck!
Basically I have a parent and child view controller, and I'm trying to pass data from the child to the parent.
//Child VC interface
#protocol ANSearchGetawayFilterDelegate
-(void)selectedCell:(NSString *)cellTitle;
#end
#interface ANSearchGetawayFilterViewController : UIViewController <UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate>
{
NSString* cellTitle;
}
#property (nonatomic, assign) id<ANSearchGetawayFilterDelegate> delegate;
#end
//Child VC implementation
#implementation ANSearchGetawayFilterViewController
#synthesize delegate = _delegate;
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *selectedCell = [tableView cellForRowAtIndexPath:indexPath];
cellTitle = selectedCell.textLabel.text;
[[self delegate] selectedCell:cellTitle];
[self dismissModalViewControllerAnimated:YES];
}
//Parent VC interface
#import "ANSearchGetawayFilterViewController.h"
#interface ANGetawayFilterViewController : UIViewController <ANSearchGetawayFilterDelegate>
{
NSString* _cellText;
}
//Parent VC Implementation
- (id)initWithNibName:(NSString*)nibNameOrNil bundle:(NSBundle*)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self)
{
// Custom initialization
ANSearchGetawayFilterViewController *search = [[ANSearchGetawayFilterViewController alloc] init];
search.delegate = self;
}
return self;
}
//delegate method
-(void)selectedCell:(NSString *)cellTitle
{
_cellText = cellTitle;
NSLog(#"cell text %#", _cellText);
}
the delegate method is never called and when is NSLog the _cellText else where it comes up as null...what am I doing wrong? Thanks!
You are most likely creating a new instance of ANSearchGetawayFilterViewController when you present it and not configuring the delegate on it.
When you called
ANSearchGetawayFilterViewController *search = [[ANSearchGetawayFilterViewController alloc] init];
search.delegate = self;
you created an instance of ANSearchGetawayFilterViewController and then set the delegate up correctly, but you never stored this instance of ANSearchGetawayFilterViewController anywhere. So later on when you come to present it you call again
ANSearchGetawayFilterViewController *search = [[ANSearchGetawayFilterViewController alloc] init];
which gives you a completely different instance, which you then need to configure again. For example
ANSearchGetawayFilterViewController *search = [[ANSearchGetawayFilterViewController alloc] init];
ANSearchGetawayFilterViewController *search1 = [[ANSearchGetawayFilterViewController alloc] init];
NSLog(#"%d", search1 == search);
#=> 0
To fix update your code to be
- (BOOL)textFieldShouldBeginEditing:(UITextField*)textField;
{
BOOL shouldBeginEditing = YES;
NSLog(#"text field should begin editing");
ANSearchGetawayFilterViewController *myANSearchGetawayFilterViewController = [[[ANSearchGetawayFilterViewController alloc] init] autorelease];
myANSearchGetawayFilterViewController.delegate = self; // <--- configure the delegate
[self presentModalViewController:myANSearchGetawayFilterViewController animated:YES];
[self closeAllPickers];
return shouldBeginEditing;
}
I wouldn't make it an ivar as the likelihood is you will present this viewController momentarily just to select some data and then get rid of it, so it is probably safe to discard it and make a new one each time.
Au contraire, the delegate method is being called (hence the NSLog()). However, _cellText is (null) because the value being passed in is nil, ergo selectedCell.textLabel.text.
Firstly, are you sure that the -selectedCell method is being called?
You can do this by putting an NSLog() before or after -tableViewDidSelectRow...
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
...
NSLog(#"TABLEVIEW DID SELECT ROW BEFORE -> %# <-", cellTitle);
[[self delegate] selectedCell:cellTitle];
NSLog(#"TABLEVIEW DID SELECT ROW DELEGATE CALLED");
...
}
Also, you might want to do some cleanup (optional)
Firstly, you are leaking in your initialisation method. Either set the ANGetawayFilterViewController as a property of the parent class using the delegate, or release it after you set the delegate.
Secondly, in the -tableViewDidSelectRow, your code assumes that the delegate has the -selectedCell method coded. If you don't have the method implemented, then the application will result in a crash. You can prevent this by checking to see if the delegate -respondsToSelector...:
if ([self.delegate respondsToSelector:#selector(selectedCell:)]) {
[self.delegate selectedCell:cellTitle];
}
Thirdly, the method of which is being called by the delegate to notify the parentViewController doesn't follow the general schema that delegate methods use, with the exception of -numberOfRowsInSection (UITableViewDelegate). Your method should contain the actual ANFilterGetawayViewController instance too:
- (void) filterGetawayViewController:(ANSearchGetawayFilterViewController *) controller didSelectCellWithTitle:(NSString *) title {
...
}
It can be called as such:
[self.delegate filterGetawayViewController:self didSelectCellWithTitle:cellTitle];
Are you using ARC? Because when the init function ends, your object (and it's reference to the delegate) are cleaned up. What happens if you make the search variable a global one (defining it in your header and initializing it in your code)?
Assuming you are using ARC:
You need to make a retained #property for your ANSearchGetawayFilterViewController instance. It will have been released by ARC by the time the delegate method is called. Do something like this.
#property (strong, nonatomic) ANSearchGetawayFilterViewController *search;
...
#synthesize search = _search;
- (id)initWithNibName:(NSString*)nibNameOrNil bundle:(NSBundle*)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self)
{
// Custom initialization
self.search = [[ANSearchGetawayFilterViewController alloc] init];
self.search.delegate = self;
}
return self;
}
Not related to your problem, but best practice is to check if the delegate actually implements the method you expect it to before calling it, like so:
if ([self.delegate respondsToSelector:#selector(selectedCell:)]) {
[self.delegate selectedCell:cellTitle];
}
I am trying to call a method thats in my ViewController from a NSObject Class thats doing some parsing.
I initally call a connection class I have made wich downloads some data from my server, I then pass this data over to a parser class I have made, now what I am trying to do is pass this data back to the viewcontroller and reload the tableview thats in this view (thats on a navigation stack)
anyway this is causing some errors and I think it might be the way I am trying to call this method thats doing it. here is how I call it.
MyViewController *myViewController = [[MyViewController alloc] init];
[myViewController initFilterArray:filteredArray];
Now I think this is causing an issue because I am allocating a new viewcontroller object? is that right.. not to sure of the terminoligy.. but yea..
the result of which is that reloaddata is only calling
numberOfSectionsInTableView
tableView:numberOfRowsInSection
then thats it.
any help would be appreciated.
UPDATE:
so I am trying to set up a protocol/delegate to see if that fixes my problem.
so in my class.h this is what I am doing
#protocol PassParsedData <NSObject>
#required
- (void) sendMyArray:(NSArray *)modelArray;
#end
//..
id <PassParsedData> delegate;
//..
#property (strong) id delegate;
then in class.m
//..method
[[self delegate]sendMyArray:filteredArray];
//..
so thats my class, then over in my view controller where I want to call this sendMyArray I do this
viewcontroller.h
#import "class.h" //delegates & protocols
//..
interface VehicleSearchViewController : UITableViewController <PassParsedData> {
//..
then i call it like this
viewcontroller.m
//..
- (void)sendArray:(NSArray *)array
{
ICMfgFilterArray = array;
[self.tableView reloadData];
}
One way of doing this would be the recommended approach of delegates and protocols.
Your NSObject declares a protocol. The ViewController actually implements the protocol and sets itself as the delegate. Then the NSObject calls the method (not knowing who implements it). It is a loosely-coupled way to communicate between objects.
I actually recently wrote a blog post on a basic introduction to protocols and delegates if you're interested...
UPDATE
Based on your update above in question.
Don't forget to set your ViewController to be the delegate.
- (void)viewDidLoad {
// State that you will take care of messages from graphView (provided you have the protocol implementation!)
self.yourClass.delegate = self;
}
And the method in your ViewController should match the protocol signature. So in ViewController.m
- (void) sendMyArray:(NSArray *)modelArray {
ICMfgFilterArray = array;
[self.tableView reloadData];
}
I am trying to pass some data back to my view controller from an object class.
This is a basic over view of what classes and views are doing, and then I will show you my code.
So ViewController, loads its tableviewcells. Then inside this delegate method it calles a connection class I have created, inside that conection class is NSURLConnection methods connecting and downloading data from the database, in the connectionDidFinishLoading method of this connection class I set up a parsing class and pass all of the downloaded data over to that.
Then I parse that data, and at the end of that parser inside parserDidEndDocument, I am trying to send the data that is now in an array variable back to my view controller to display. However.. for some reason my protocols and delegates are not working.
I have set up protocols inside m parser class and set the delegates in my view controller but it never makes it to my protocol method.
I will show you my code below.
parserclass.h
#protocol PassParsedData <NSObject>
#required
- (void)sendManufactureArray:(NSArray *)array;
#end
//..
id <PassParsedData> delegate;
//..
#property (strong) id delegate;
//
parserclass.m
#import "VehicleSearchViewController.h"
//..
#synthesize delegate;
//..
- (void)parserDidEndDocument:(NSXMLParser *)parser
{
//.. array stuff is set up and i can log it so i know its working.. i just want to show you the protocol and delegate stuff to be clear
[[self delegate]sendManufactureArray:filteredArray];
}
Then moving onto my view controller where I am hoping to call the protocol and get the filteredArray data back.
ViewController.h
#import "EngineResponses.h" //delegates & protocols
//..
#interface SearchViewController : UITableViewController <PassParsedData> {
//..
Viewcontroller.h
#import "EngineResponses.h"
//..
- (void)viewDidLoad
{
[super viewDidLoad];
//..
parserClass *pc = [[parserClass alloc] init];
[pc setDelegate:self];
//..
}
- (void)sendManufactureArray:(NSArray *)array //Breakpoint here is never accessed
{
FilterArray = array;
[self.tableView reloadData];
}
As you can see in that last method which is the protocol I am calling, its never accessed by the thread. I have checked, This call
[[self delegate]sendManufactureArray:filteredArray];
gets accessed fine.. but it just never makes it back to the View Controller.. any ideas... am I missing anything? .. im at a complete loss, been working on this all day.
any help would be HUGELY appreciated! :)
UPDATE:
I have added this to my ViewController.h
//..
ParserClass *parserclass;
//..
#property (strong, nonatomic) ParserClass *parserclass;
//..
viewcontroller.m
#synthesize parserclass;
//..
//then I call this in viewdidload
[engineResponses setDelegate:self];
As others have said in the comments, your pc variable is being deallocated at the end of the viewDidLoad block, since the only reference it has goes out of scope there. If you want it to live on, you must enlarge its scope (i.e. make it an instance variable).
i've been dancing with a tambourine for a while, but still don't know what's the reason for that error.
I've got a tableView with history of user queries data from sqlite base. I'm new to iPhone developing, so my code may be a bit excessive. The hierarchy is:
HistoryModel
model-object with some init methods
HistoryDataController
gets data from database and presents an array of HistoryModel objects
HistoryViewController
subclass of UITableView, displays data
AppDelegate
there i initially store an array of HistoryModel objects (by getting it from HistoryDataController) for HistoryViewController to access it.
The problem is, when i scroll the table or open the tab with it for the second time - it crashes with -[CFString retain]: message sent to deallocated instance
Code:
HistoryModel.h
pretty unnecessary class for that case, but i want that worked to repeat in several identical cases, but a bit more complicated
#interface HistoryModel : NSObject {
int entry_id;
NSString *word;
}
- (id)initWithWord:(NSString *)word;
- (id)initWithWord:(NSString *)word andId:(int)entry_id;
#property int entry_id;
#property (retain) NSString *word;
#end
HistoryModel.m
#implementation HistoryModel
#synthesize entry_id, word;
- (id)initWithWord:(NSString *)_word {
[super init];
word = _word;
return self;
}
- (id)initWithWord:(NSString *)_word andId:(int)_entry_id {
entry_id = _entry_id;
return [self initWithWord:_word];
#end
HistoryDataController.h
i use the entity of that class as getter of data and a storage for HistoryModel objects (in historyEntries property)
#interface HistoryDataController : NSObject {
NSMutableArray *historyEntries;
int limit;
}
#property (nonatomic, retain) NSMutableArray *historyEntries;
#property int limit;
- (id)initWithHistoryData;
- (id)initWithHistoryDataLimitedBy:(int)limit;
HistoryDataController.m
#implementation HistoryDataController
#synthesize historyEntries, limit;
- (id)initWithHistoryDataLimitedBy:(int)_limit {
[super init];
// Getting data from database
{some DB stuff}
NSMutableArray *tmp_historyEntries = [[NSMutableArray alloc] init];
while(result == SQLITE_ROW)
{
HistoryModel *currentHistoryEntry = [[HistoryModel alloc] initWithWord:[NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, 1)] ];
[tmp_historyEntries addObject:currentHistoryEntry];
result = sqlite3_step(statement);
}
historyEntries = tmp_historyEntries;
{some DB stuff}
return self;
}
#end
HistoryViewController.h
subclass of UITableViewController, gets data stored in AppDelegate's property and displays in the table
#interface HistoryViewController : UITableViewController {
IBOutlet UITableView *historyTable;
SynonymsAppDelegate *appDelegate;
}
#property (retain) UITableView *historyTable;
#end
HistoryViewController.m
#implementation HistoryViewController
#synthesize historyTable, historyEntriesToShow;
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
appDelegate = (SynonymsAppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate initHistoryList];
[self.tableView reloadData];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
{standart cell stuff}
HistoryModel *historyEntry = [appDelegate.historyList objectAtIndex:indexPath.row];
cell.textLabel.text = historyEntry.word;
return cell;
}
#end
SynonymsAppDelegate.h
when history tab opens, it gets data of historyList property, that was formed by HistoryDataController :)
#interface SynonymsAppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate> {
...
NSMutableArray *historyList;
}
...
#property (retain) NSMutableArray *historyList;
- (void)initHistoryList;
#end
SynonymsAppDelegate.m
#implementation SynonymsAppDelegate
#synthesize window, tabBarController, historyList;
- (void)initHistoryList {
HistoryDataController *historyDataController = [[HistoryDataController alloc] initWithHistoryData];
historyList = historyDataController.historyEntries;
}
#end
Fuf. Sorry for so much code, but i believe that's all necessary.
As a result of half the day spent on this question, i may guess, that problem is somehow connected with HistoryModel entity, because when i delete "retain" for word #property, the error switches for -[CFString isEqualToString:]: message sent to deallocated instance
I'm not really experienced in memory management, but i guess this HistoryModel objects inside historyEntry in HistoryViewController or in historyList in AppDelegate releases somehow, when scrolling the table or opening the tab for the second time.
But this's just my guessing.
Really appreciate the help.
You definitely have an issue in your -[HistoryModel initWithWord] You should retain (or better yet copy) the string that is being passed.
I would write it like this:
- (id)initWithWord:(NSString *)_word {
[super init];
self.word = _word; // this is same as [self setWord:_word]
return self;
}
There are some who would say using the setter in your init is not a good practice. I'm not of that camp. But in any case, you need to be retaining or copying that string.
Then you have a similar issue in your app delegate where you are leaking each HistoryDataController as you create a new one. (and that happens every time that tableview appears). And you really should be retaining that array as well (although that hasn't caused a problem yet because you're leaking the HistoryDataControllers and therefore masking that issue so far.)
My general advice to you would be don't put off memory management. To come back later and try to get it right is complicated and error-prone even for an experienced developer. It is much, much easier to build the correct memory management techniques into the code as you write it. This means it's well worth your time to read the memory management guide first before you start coding something like this. You'll save yourself a lot of time and frustration.