Ok, I spent the last 8 hours fighting with it - it just seems beyond me. Here's my complete (relevant) code:
- (void)updateUserDefaults
{
NSMutableDictionary *viewControllerDetails = [[NSMutableDictionary alloc] initWithCapacity:4];
[viewControllerDetails setObject:[NSNumber numberWithInt:OOVenueClassControllerType] forKey:#"classType"];
[viewControllerDetails setObject:self.searchTerm forKey:#"searchTerm"];
[viewControllerDetails setObject:self.searchLocation forKey:#"searchLocation"];
//----- the next two lines cause the problem
NSString *res = [[NSString stringWithFormat:#"%#",[searchResults xmlString]] retain];
[viewControllerDetails setObject:res forKey:#"searchresults"];
//-----
NSMutableArray *viewControllersList = [NSMutableArray array] ;
[viewControllersList addObject:viewControllerDetails];
NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];
//the following line causes the error
[defs setObject:viewControllersList forKey:kViewControllersKey];
[defs synchronize];
[res release];
}
Note the block with the next two lines cause the problem. At first I didn't create another string, but added it later while trying to solve the problem.
If I comment out those two lines, everything works fine. If I put them back in, I get
- [CFString class]: message sent to deallocated instance 0xa1a9000
Is something is wrong with the string that I'm trying to put into the userdefaults? That string is rather large (about 200,000 characters), but I had stored even longer strings in user defaults in the past.
It's also worth noting that if I uninstall the app, then everything works fine. But on subsequent runs the problem exhibits itself.
So, how and why and where is the string getting deallocated? I have explicitly added retain - but that still doesn't help. What am I missing?
Edit: just realised I forgot to say that the error is thrown on line
[defs setObject:viewControllersList forKey:kViewControllersKey];
Also, for general information, method - (NSString *)xmlString on searchResults does exactly what the name means: creates an XML string with the information from that object.
Edit 2: I tried doing something else with that string - convert it to NSData, compress using zlib - but regardless of data type, that particular object gets deallocated. Does it have to do something with the size of the string?
NSString *res = [[NSString stringWithFormat:#"%#",[searchResults xmlString]] retain];
Is auto released. You don't need to release it at the end of your method. You are over-releasing it.
Further, you don't need to retain the [searchResults xmlString]. The stringWithFormat method already does it for you.
Good Luck!
Ok, not sure what exactly the problem was, but it was somewhere in the searchResults and/or xmlString method. searchResults object is originally created from XML received from the server (XML is parsed into the object structure). When xmlString was called, for some reason the string I was getting back was different from the original XML (I'm not talking about formatting, of course) - of 200,000 char-long string, within the first 500 chars or so there were some differences. I haven't been able to figure out why. So, instead of recreating the xml from object structure, I instead stored the original XML in a field in that object and, when xmlString was called, simply returned the original string. Now everything worked fine.
Thank you all for your support through this painful process.
Related
I´m having a great deal of trouble with a bugg that in some cases gives the "initWithObjects:forKeys:count:]: attempt to insert nil object from objects[6]'" error message. It´s only occurring around every third trial and in the other cases it works fine. I haven´t debugged buggs that happeds at certain situations so that´s whyI´m asking for help. It might be difficult to find a solution but I would be glad to receive some advice atleast where to start look for the issue and how to debug it?
Basically my app have a method that sends a NSDictonary list with objects to a server. In some cases I want to remove an object if the user have´t chosen anything for that list. Problem is that the server died´t like sending an object with an empty space. So I made a kind of not nice looking work around. Basically The IBaction checks if the Object contains nil. If it contains nil it redirects to a very similar NSDictonary without the Object containing Nil. It woks in some cases but it seems like it sometimes don´t recognize the object containing nil.
Here´s the code in Inaction that redirects the code. I haven´t created a method for inserting anything to the object:#"DefaultCreateImageID" yet so as far as I know it should always be nil.
NSString *Imagestuff= [[NSUserDefaults standardUserDefaults] objectForKey:#"DefaultcreateImageID"];
if ( [[NSUserDefaults standardUserDefaults] objectForKey:#"DefaultcreateImageID"] != ( NSString *) [NSNull null] ){
DataHandler *handler = [DataHandler sharedDatahandler];
handler.authenticateUserDelegate = self;
[handler createActivityNoImage];
NSLog(Imagestuff);
}
else
{
DataHandler *handler = [DataHandler sharedDatahandler];
handler.authenticateUserDelegate = self;
[handler createActivity];
}
Thanks!
If you get an error "Trying to insert nil" then one of the objects you are trying to add to the dictionary is nil. Solution: Don't do that.
Figure out why some item you are trying to add to the dictionary is nil. Then figure out what you want to do in the situation.
To follow up on gnashers729 answer. The problem for me isn't nil but the fact my Inaction fails to reqognize what the object contains.
Here for example I tried to replace nil with a string to reqognize. I get the same problem that my method in some cases recognize the string and in some cases don´t.
NSString *Imagestuff= [[NSUserDefaults standardUserDefaults] objectForKey:#"DefaultcreateImageID"];
if ( [[NSUserDefaults standardUserDefaults] objectForKey:#"DefaultcreateImageID"] != ( NSString *) #"noImage" ){
I see this issue has been asked a bit but all the answers seem to point to the cause being trying to update an object when the context has been deleted. I don't think I'm doing that but I'm getting the error so I'm confused (admittedly, I'm shaky on managing retention and references to begin with).
I have an Entity that holds user preferences as essentially key-value records. One of them is an email address.
UserPreference *prefEmailAddress;
#property (nonatomic, retain) UserPreference *prefEmailAddress;
In my class, in my ViewWillAppear method, I build a fetch request and get a reference to the email address value and set a UI text box to the value. This works fine.
NSArray *prefs = [context executeFetchRequest:request error: &error];
if ([prefs count] > 0) {
prefEmailAddress = [prefs objectAtIndex:0];
[prefEmailAddress setValue:emailAddress.text forKey:#"prefValue"];
}
However, in another method when I try to save the potentially modified text box text back to the object, I get the above crash.
I'm just doing this;
NSLog(#"Addr: %#",emailAddress.text);
// [prefEmailAddress setValue:emailAddress.text forKey:#"prefValue"];
The last line causes the exception. Seems like the prefEmailAddress object should still exist but it apparently doesn't.
Thanks for any hints on this.
I solved mine by removing
[fetchRequest setFetchBatchSize:<INT_VALUE>];
if this is in your code when fetching request.
What I'm doing:
I am reading some data off a file several times while my app runs. I use the following code to do so:
NSString *dataPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"data.txt"];
NSString *data = [NSString stringWithContentsOfFile:dataPath encoding:NSStringEncodingConversionExternalRepresentation error:NULL];
NSArray *components = [data componentsSeparatedByString:#"|||||"];
The first time this is called, it works as expected - I get an array of length 5, each section containing a relevant string.
What goes wrong:
This file is never modified. Yet, when I call the same procedure a second time (or third, fourth etc) I don't get the same result. Instead, an array of length 1 is returned, containing only part of the necessary data.
Why? I can't see any reason for this to go wrong... any help is much appreciated!
Since the file is in you AppBundle this means that you can't modify this file at all.
Are you sure that, where ever this code is called, the autorelease object are retained correctly?
If you call this block of code every time you want this data, it might be an idea to save the results of the first time and use that every time. This will speed things up a bit.
Turns out that the code works fine. The problem was elsewhere in my code, where I was (accidentally) accessing protected directories. As a result, iOS blocked my app from accessing any files at all :o
Okay, I'm trying to write a high score function for my app.
My problem is that when no high score has been saved yet, my program crashes.
If I save it with:
[[NSUserDefaults standardUserDefaults] setObject:#"[given string]" forKey:#"firstName"];
first, it works fine. However, if I start up the program for the first time and try to view the high scores with the following code:
first = [[NSString alloc] initWithString:[[NSUserDefaults standardUserDefaults] objectForKey:#"firstName"]];
bad things happen.
Basically, is there away to see if nothing yet exist under firstName? Is there a way to initialize without erasing any name that might already be present?
Thanks.
The NSString documentation for initWithString: says
Parameters
aString
The string from which to copy characters. This value must not be nil.
The documentation for objectForKey: says
Return Value
The object associated with the
specified key, or nil if the key was
not found.
The problem seems to be that there is a nil returned when you try to retrieve firstName that doesn't exist yet and try to create a NSString with it as input.
The NSUserDefaults instance method registerDefaults: is meant for exactly this purpose: You can set default values for your preferences that will be overridden by any other value set for the same preference key. Just make sure to call it early enough that it will run before any code that needs to access your preferences.
You could load "first" like this:
first = [[[NSUserDefaults standardUserDefaults] objectForKey:#"firstName"] retain];
if (!first) {
// set default or do something else if there wasn't a value saved
first = #"N/A";
}
I'm converting data (from a web page) to a string). The basic code works (but there's been some subtle change somewhere - maybe on server).
NSLog shows the expected string (maybe 1000 chars long). However, when I float over responseString, it shows "Invalid". Worse, parsing with componentsSeparatedByCharactersInSet does not work.
Ideas?
NSString *responseString;
responseString = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];
NSLog([NSString stringWithFormat:#"responsestring ='%#'",responseString]);
if ([responseString compare:#""] != NSOrderedSame) {
lines = [responseString componentsSeparatedByCharactersInSet: [NSCharacterSet characterSetWithCharactersInString:#";"]];
This may happen when the configuration is set to "Release" rather than "Debug" I think.
Do not trust what the debugger says, it is not accurate, this has happened to me and took me a while to realise that the xcode debugger is not always right and should not be trusted, so i no longer trust the debugger and i use nslog statements whenever it tries to tell me something is invalid. So dont worry about it it happens, and when it happened to me I was also parsing responses from some webservice.
Just to be clear -- my experience with seeing "Invalid" in the debugger means that the reference is to an already-released object.
Your question and the comments below seem to suggest that you are thinking "Invalid" is an actual string value -- but are you sure you don't just have a memory management probably?