Crashing in -dealloc with message sent to deallocated instance - objective-c

Whenever I build and run I get no errors or warnings. Then I tried setting NSZombieEnabled. I get the following crash:
2011-12-06 16:08:46.869 APITextProject[4194:207] * -[APITextProjectViewController dealloc]: message sent to deallocated instance 0x5a31480
Here is my code:
#pragma ASI Delegate methods
- (void)requestFinished:(ASIHTTPRequest *)request
{
NSLog(#"Request finished successfully");
NSLog(#"%#",[request responseString]);
NSDictionary *responseDictionary = [[request responseString]JSONValue];
NSDictionary *arrayElement = [responseDictionary objectForKey:#"user"];
NSString *ID = [arrayElement valueForKeyPath:#"id"];
NSLog(#"id: %d",ID);
NSString *usr = [arrayElement valueForKeyPath:#"usr"];
NSLog(#"usr: %#",usr);
NSString *gd = [arrayElement valueForKeyPath:#"gd"];
NSLog(#"gd: %#",gd);
NSString *age = [arrayElement valueForKeyPath:#"ag"];
NSLog(#"ag: %#",age);
NSString *st = [arrayElement valueForKeyPath:#"st"];
NSLog(#"st: %#",st);
NSString *lf = [arrayElement valueForKeyPath:#"lf"];
NSLog(#"lf: %#",lf);
NSString *da = [arrayElement valueForKeyPath:#"da"];
NSLog(#"da: %d",da);
for(NSString *value in [arrayElement allValues]){
NSLog(#"Found Value %#",value);
label.text = value;
[super release];
}
}

Please delete this line.
[super release];
It should NEVER make sense to call release on super.

I have a feeling your problem lies in the line [super release] inside the for loop.

Why are you calling [super release] in your request delegate method? Why would you ever call super release?

Related

Why would a property essentially disappear? Obj-C, Cocoa

I am quite stumped. I have an app with a class for storing item details. Called LEItem. Those items are stored in a store with a class labeled LEItemStore. I have a view with a table of all items. This works fine. If you tap on a row, it sends this message to LogbookFirstViewController.
LogbookFirstViewController *logController = [[LogbookFirstViewController alloc] initForNewItem:NO];
NSArray *items = [[LEItemStore sharedStore] allItems];
LEItem *selectedItem = [items objectAtIndex:[indexPath row]];
NSString *description = [selectedItem description];
NSLog(#"%#", description);
[logController setItem:selectedItem];
[self dismissViewControllerAnimated:YES completion:nil];
That is in a TableView class. In the LogbookFirstViewController.m I have
-(void)setItem:(LEItem *)i{
item = i;
NSString *t = [item description];
NSLog(#"In LogbookFirstViewController, returning %#", t);
}
This is where it gets odd. That works. It outputs the correct item, therefore I would think everything would be okay. But it's not. item is a class-level property, so it should stay, but it doesn't. In the same class, I have overrode this method.
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
//NSString *string = [item description];
//NSLog(#"Item = %#", string);
NSLog(#"View did Appear:animated");
int glucoseValue = [item glucose];
NSString *glucoseString = [NSString stringWithFormat:#"%d", glucoseValue];
[glucoseField setText:glucoseString];
int proteinValue = [item protein];
NSString *proteinString = [NSString stringWithFormat:#"%d", proteinValue];
[proteinField setText:proteinString];
int carbsValuue = [item carbs];
NSString *carbsString = [NSString stringWithFormat:#"%d", carbsValuue];
[carbsField setText:carbsString];
int insulinValue1 = [item insulin];
NSString *insulin1String = [NSString stringWithFormat:#"%d", insulinValue1];
[insulinField1 setText:insulin1String];
int insulinValue2 = [item insulin2];
NSString *insulinString2 = [NSString stringWithFormat:#"%d", insulinValue2];
[insulinField2 setText:insulinString2];
//NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
//[dateFormatter setDateStyle:NSDateFormatterShortStyle];
//[dateFormatter setTimeStyle:NSDateFormatterShortStyle];
//NSLog(#" The item was created on %#", [dateFormatter stringFromDate:[item dateCreated]]);
//[dateButton setTitle:[dateFormatter stringFromDate:[item dateCreated]] forState:UIControlStateNormal];
NSString *t = [item description];
NSLog(#"Loading view... Returns: %#", t);
}
I know that it isn't the cleanest code, but the idea is the same. It uses exactly the same code as the setItem: method. However, this always returns (null). Why? The property appears to go missing at viewWillAppear.
Thanks.
EDIT
I solved the problem. As you can see, the checked answer below did give the right idea, here is what I did to solve it. The problem was that when I sent setItem: I used this code to get LogbookFirstViewController
LogbookFirstViewController *logController = [[LogbookFirstViewController alloc] initForNewItem:NO];
As I know see, that created a new instance of LogbookFirstViewController, so therefore, the existing one did not change it's Item property, as properties are assigned to one instance. Therefore, I was only changing the value of Item for this "invisible" property.
To solve this, one must get the existing instance of the viewController. To do this I did the following:
In LogbookFirstViewController.h I added this property
#property (assign) LogbookFirstViewController *instance;
Then, synthesize instance in your .m and in the same placed I added this to viewDidLoad
- (void)viewDidLoad
{
instance = self;
...
Then, in the other viewController, entriesViewController, I added this too the .h
#property (nonatomic, strong) LogbookFirstViewController *logController;
Synthesize it. Then, I just used my didSelectRowAtIndexPath the same way, just using the existing logController
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSArray *items = [[LEItemStore sharedStore] allItems];
LEItem *selectedItem = [items objectAtIndex:[indexPath row]];
NSString *description = [selectedItem description];
NSLog(#"%#", description);
NSLog(#"Setting controller: %#", logController);
[logController setItem:selectedItem];
[self dismissViewControllerAnimated:YES completion:nil];
}
Then it works!
You have a line where you create the LogbookFirstViewController but you don't actually cause it to display anything (push or present). Since it's a local variable, it would appear that whatever instance of that controller is loading its view is not the same one that you initialize in the code you've shown.
You can verify this by adding a couple of NSLog lines, such as:
NSLog(#"Setting controller: %#", logController); // Insert before existing line
[logController setItem:selectedItem];
...and...
[super viewWillAppear:animated];
NSLog(#"Viewing controller: %#", self); // Insert after existing line
For things to work the way you want, those have to print the same address.
You should retain when assigning object to property without ARC:
-(void)setItem:(LEItem *)i{
_item = [i retain];
...
}
If you use property with ARC, then write _item = i;:
-(void)setItem:(LEItem *)i{
_item = i;
...
}

Message wont connect to method

I'm kind of new to this, so it might be a beginners mistake. The problem is that when i send a message to a method it doesn't connect.
Here's the calling method:
-(BOOL) login:(LoginInfo *) info{
NSString *url = [NSString stringWithFormat:#"%#/%#?name=%#&password=%#", FAMORABLE_API_URL,FAMORABLE_API_ACTION_LOGIN, info.username, info.password];
NSDictionary* json = [self getJson:url];
NSString *token = [json objectForKey:#"Token"];
NSLog(#"results: %#", token);
LoginInfo *loginResult = [LoginInfo alloc];
loginResult.token = token;
//TODO
NSLog(#"test 1 %#", loginResult.token);
[clientService saveLoginInfo:loginResult];
return YES;
}
On the line above the last you can see I'm sending to saveLoginInfo in clientService which is declared in ClientService.h which is imported in this file.
-(void) saveLoginInfo:(LoginInfo *)info{
NSLog(#"test 2 %#", info);
NSLog(#"test 3%#", info.token);
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:info.token forKey:KEY_TOKEN];
NSString *string = [defaults stringForKey:KEY_TOKEN];
NSLog(#"test 4%#", string);
// save it
[defaults synchronize];
if (!(info.token)){
self.currentUser = nil;
self.isLoggedOn=false;
}else{
self.currentUser = info;
self.isLoggedOn=true;
}
}
This is the method being called. I've put out a bunch of logs, mostly as a safe if i did one wrong, but none of them are being executed...
Do you have any ideas of what might be wrong?
Thanks in advance
Tom
Is clientService in the line [clientService saveLoginInfo:loginResult]; an instance variable in your class?
If so, make sure that you have instantiated the object somewhere before you call it. (Either in your class's init method, or possibly viewDidLoad if it's a UIViewController.)
E.g.
- (void)viewDidLoad {
[super viewDidLoad];
clientService = [[MyClientService alloc] init];
}
- (id)init {
self = [super init];
if (self) {
clientService = [[MyClientService alloc] init];
}
return self;
}
(Make sure you also release the instance in the dealloc method.

How to convert NSUrl to NSString?

After AVAssetExportSession has complete export video.
I have plan to garb Video Path to upload via Youtube.
but [GDataUtilities MIMETypeForFileAtPath:path defaultMIMEType:#"video/mp4"];
it only accept NSString.
Is it possible to convert NSUrl in to NSString for video file path.
i have try to use NSString *path = [ExportoutputURL absoluteString];
but it crash.
Here is the Code
- (void)exportDidFinish:(AVAssetExportSession*)session {
ExportoutputURL = session.outputURL;
_exporting = NO;
NSIndexPath *exportCellIndexPath = [NSIndexPath indexPathForRow:2 inSection:kProjectSection];
ExportCell *cell = (ExportCell*)[self.tableView cellForRowAtIndexPath:exportCellIndexPath];
cell.progressView.progress = 1.0;
[cell setProgressViewHidden:YES animated:YES];
[self updateCell:cell forRowAtIndexPath:exportCellIndexPath];
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
if ([library videoAtPathIsCompatibleWithSavedPhotosAlbum:ExportoutputURL]) {
[library writeVideoAtPathToSavedPhotosAlbum:ExportoutputURL
completionBlock:^(NSURL *assetURL, NSError *error){
dispatch_async(dispatch_get_main_queue(), ^{
if (error) {
NSLog(#"writeVideoToAssestsLibrary failed: %#", error);
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:[error localizedDescription]
message:[error localizedRecoverySuggestion]
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alertView show];
[alertView release];
}
else {
_showSavedVideoToAssestsLibrary = YES;
ExportCell *cell = (ExportCell*)[self.tableView cellForRowAtIndexPath:exportCellIndexPath];
[cell setDetailTextLabelHidden:NO animated:YES];
[self updateCell:cell forRowAtIndexPath:exportCellIndexPath];
NSArray *modes = [[[NSArray alloc] initWithObjects:NSDefaultRunLoopMode, UITrackingRunLoopMode, nil] autorelease];
[self performSelector:#selector(hideCameraRollText) withObject:nil afterDelay:5.0 inModes:modes];
}
});
}];
}
[library release];
}
- (void)uploadVideoFile {
NSString *devKey = DEVELOPER_KEY;
GDataServiceGoogleYouTube *service = [self youTubeService];
[service setYouTubeDeveloperKey:devKey];
NSURL *url = [GDataServiceGoogleYouTube youTubeUploadURLForUserID:kGDataServiceDefaultUser];
// load the file data
NSString *path = [ExportoutputURL absoluteString];//[[NSBundle mainBundle] pathForResource:#"video_2451" ofType:#"mp4"];//[mFilePathField stringValue];
NSFileHandle *fileHandle = [NSFileHandle fileHandleForReadingAtPath:path];
NSString *filename = [path lastPathComponent];
// gather all the metadata needed for the mediaGroup
NSString *titleStr = #"Upload Test";//[mTitleField stringValue];
GDataMediaTitle *title = [GDataMediaTitle textConstructWithString:titleStr];
NSString *categoryStr = #"Entertainment";//[[mCategoryPopup selectedItem] representedObject];
GDataMediaCategory *category = [GDataMediaCategory mediaCategoryWithString:categoryStr];
[category setScheme:kGDataSchemeYouTubeCategory];
NSString *descStr = #"GData Description";//[mDescriptionField stringValue];
GDataMediaDescription *desc = [GDataMediaDescription textConstructWithString:descStr];
NSString *keywordsStr = #"RAGOpoR Demo";//[mKeywordsField stringValue];
GDataMediaKeywords *keywords = [GDataMediaKeywords keywordsWithString:keywordsStr];
BOOL isPrivate = NO;//([mPrivateCheckbox state] == NSOnState);
GDataYouTubeMediaGroup *mediaGroup = [GDataYouTubeMediaGroup mediaGroup];
[mediaGroup setMediaTitle:title];
[mediaGroup setMediaDescription:desc];
[mediaGroup addMediaCategory:category];
[mediaGroup setMediaKeywords:keywords];
[mediaGroup setIsPrivate:isPrivate];
NSString *mimeType = [GDataUtilities MIMETypeForFileAtPath:path
defaultMIMEType:#"video/mp4"];
// create the upload entry with the mediaGroup and the file
GDataEntryYouTubeUpload *entry;
entry = [GDataEntryYouTubeUpload uploadEntryWithMediaGroup:mediaGroup
fileHandle:fileHandle
MIMEType:mimeType
slug:filename];
SEL progressSel = #selector(ticket:hasDeliveredByteCount:ofTotalByteCount:);
[service setServiceUploadProgressSelector:progressSel];
GDataServiceTicket *ticket;
ticket = [service fetchEntryByInsertingEntry:entry
forFeedURL:url
delegate:self
didFinishSelector:#selector(uploadTicket:finishedWithEntry:error:)];
[self setUploadTicket:ticket];
GTMHTTPUploadFetcher *uploadFetcher = (GTMHTTPUploadFetcher *)[ticket objectFetcher];
}
Error EXC_BAD_ACCESS at
NSString *path = [ExportoutputURL absoluteString];
Is it possible to convert NSUrl in to NSString for video file path.
Yes. Send it an absoluteString message.
i have try to use NSString *path = [ExportoutputURL absoluteString]; but it crash.
If you want a path, send the URL a path message. A string representing a URL is generally not a valid path; if you want a path, ask it for one.
As for the crash, it does not mean absoluteString is wrong. Sending absoluteString to an NSURL object is the correct way to get an NSString object that represents the URL. The problem is somewhere else.
Error EXC_BAD_ACCESS at
NSString *path = [ExportoutputURL absoluteString];
This probably means that ExportoutputURL points to something that is not nil but is also not a valid object. It might have pointed to an NSURL object at some point, but it doesn't now.
My guess would be that the problem is this:
ExportoutputURL = session.outputURL;
You assign the URL to the ExportoutputURL instance variable, but you don't retain the object or make your own copy. Therefore, you don't own this object, which means you are not keeping it alive. It may die at any time, most probably after this method (exportDidFinish:) returns.
The crash is because you call uploadVideoFile later, after the URL object has already died. You still have a pointer to it, but that object no longer exists, so sending a message to it—any message—causes a crash.
There are three simple solutions:
Retain the URL object when you assign it to your instance variable.
Make your own copy of the URL object and assign that to the instance variable.
Declare ExportoutputURL as a property, with either the strong keyword or the copy keyword, and assign the object to the property, not the instance variable. That will call the property's setter, which, if you synthesize it or implement it correctly, will retain or copy the URL for you.
Either way, you will own the object, and that will keep it alive until you release it. Accordingly, you will need to release it when you are done with it (in dealloc, if not earlier), so that you don't leak it.
This all assumes that you are not using ARC. If you are using Xcode 4.2 or later, and can require iOS 4 or later, you should migrate your project to ARC, as it makes so many things much simpler. You would not need to retain or copy this object if you were using ARC, which means that migrating to ARC now is a fourth solution (but certainly a larger-scale one).
Use either absolutePath or path as mentioned by Miek and Nepster. Expanding on their answers, the difference between lies in the prefix.
NSString* string1 = [url absoluteString]; // #"file:///Users/jackbrown/Music/song name.mp3"
NSString* string2 = [url path]; // #"/Users/jackbrown/Music/song name.mp3"`
NSString *path = [[NSString alloc] initWithString:[url path]]; ?
Use this. I think it will help you.
In Objective c
NSString *testString = testUrl.absoluteString;
In Swift
var testString : String = testUrl.absoluteString
Simply you can do it like this.
NSString *myString = [myURL absoluteString];

EXC_BAD_ACCESS error help

I am new to objective-c and i cannot figure out how memory handling works exactly in this language. Here is some code i wrote from a turorial and i am confused why when i uncomment the [filePath release] i get an error even though the method is finished. I read some articles on how memory handling works but i cant see what i am doing wrong here.
#import "saaving_dddaaattaViewController.h"
#implementation saaving_dddaaattaViewController
#synthesize field;
-(NSString *)pathOfFile {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsFolder = [paths objectAtIndex:0];// paths[0] = documents directory
return [documentsFolder stringByAppendingFormat:#"myfile.plist"];
}
-(void)applicationWillTerminate:(NSNotification *)notification {
NSLog(#"Saving data...");
NSMutableArray *array = [[NSMutableArray alloc]init];
[array addObject:field.text];
[array writeToFile:[self pathOfFile] atomically:YES];
[array release];
}
- (void)dealloc {
[field release];
[super dealloc];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
#pragma mark - View lifecycle
- (void)viewDidLoad {
NSString *filePath = [self pathOfFile];
if ([[NSFileManager defaultManager]fileExistsAtPath:filePath]) {
NSLog(#"File[%#] does exist.", filePath);
NSArray *array = [[NSArray alloc]initWithContentsOfFile:filePath];
field.text = [array objectAtIndex:0];
[array release];
}
UIApplication *app = [UIApplication sharedApplication];
[[NSNotificationCenter defaultCenter]addObserver:self selector:#selector(applicationWillTerminate:) name:UIApplicationWillTerminateNotification object:app];
//[filePath release];// <--- commented out release
[super viewDidLoad];
}
- (void)viewDidUnload {
[super viewDidUnload];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#end
Memory Management can be confusing at first. Only release objects that you have created. This is almost only if you use the words alloc, init, retain.
The problem in your case is that you do not actually own the object, it is autoreleased, because you did not alloc, init or retain it. This is fine, but it is not your job to release it, so don't worry about it.
If you get "EXC_BAD_ACCESS" errors later, it might be helpful to use NSZombies to help find where you are releasing incorrectly. They work by placing a "zombie" in memory wherever you release an object so it is easier to tell what the problem is.
EDIT: For example, say you have:
NSString *foo = [[NSString alloc] initWithString:#"foo"];
NSString *bar = [NSString stringWithString:#"bar"];
You would have to release foo, by calling: [foo release]; at some point, but you would not have to release bar because it you did not use alloc to allocate memory for it. This goes for any type of object, not just NSString. A great website explaining this can be found here.

Objective C - UITableView after calling reloadData my object properties are null/nil

I have a ViewController defined as follows:
#interface SectionController : UITableViewController {
NSMutableArray *sections;
}
- (void) LoadSections;
When LoadSection is call it makes a call to NSURLConnection to load a url which in turn calls
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
[connection release];
[responseData release];
NSDictionary *results = [responseString JSONValue];
NSMutableArray *jSections = [results objectForKey:#"Items"];
sections = [NSMutableArray array];
for (NSArray* jSection in jSections)
{
Section* section = [Section alloc];
section.Id = [jSection objectForKey:#"Id"];
section.Description = [jSection objectForKey:#"Description"];
section.Image = [jSection objectForKey:#"Image"];
section.Parent = [jSection objectForKey:#"Parent"];
section.ProductCount = [jSection objectForKey:#"ProductCount"];
[sections addObject:section];
[section release];
}
[jSections release];
[results release];
[delegate sectionsLoaded];
[self.view reloadData];
}
The data parses correctly and I now have sections filled with many items.
Calling [self.view reloadData] forces a callback to the delegate method cellForRowAtIndexPath which should then present the data into the cell however its at this point that sections is now nil again.
Can someone please point out my mistake? I must admit I am a newbie to objective c and it probably a pointer issue. What is need to do is retain the value of sections after calling reloadData.
Many thanks.
Seeing the new code the problem is obvious:
sections = [NSMutableArray array];
should become
[sections release];
sections = [[NSMutableArray alloc] init];
note that the array does not become again "nil", is instead deallocated and you get an invalid reference, which might (should) generate a crash on dereferencing.
I suggest you to read some articles on reference counted memory management as it might be not obvious if you are new to Objective-C, and often leads to mistake (i.e: autorelease is not magic at all)
best way to avoid all memory leaks here is just simply use #property (nonatomic, retain) NSMutableArray *sections; by using property you can be sure that all men management works will be correctly managed by system. Just don't forget that property retains value when you doing setSections:, so that you need to pass autoreleased object here.
self.sections = [NSMutableArray array];
...
[self.sections addObject:section];
Also to avoid all problem try to make all objects which should live only in this method autorelease. Like this:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *responseString = [[[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding] autorelease];
NSDictionary *results = [responseString JSONValue];
NSMutableArray *jSections = [results objectForKey:#"Items"];
self.sections = [NSMutableArray array];
for (NSArray* jSection in jSections) {
Section* section = [[[Section alloc] init] autorelease];
section.Id = [jSection objectForKey:#"Id"];
section.Description = [jSection objectForKey:#"Description"];
section.Image = [jSection objectForKey:#"Image"];
section.Parent = [jSection objectForKey:#"Parent"];
section.ProductCount = [jSection objectForKey:#"ProductCount"];
[self.sections addObject:section];
}
[delegate sectionsLoaded];
[self.view reloadData];
}
And also most of object you trying to release already autoreleased:
all params passed into your method shouldn't be released manually, check I think JSONValue also should returns autoreleased object and anything you getting by enumerating or by call objectForKey: