Can't figure out about saving files - objective-c

I am trying to save my object to the file system on an iPad, but I seem to be doing something wrong. Here is how I have archived the object:
NSString *localizedPath = [self getPlistFilePath];
NSString *fileName = [NSString stringWithFormat:#"%#.plist", character.infoName];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:character];
fileName = [fileName stringByReplacingOccurrencesOfString:#" " withString:#"_"];
localizedPath = [localizedPath stringByAppendingPathComponent:fileName];
NSLog(#"File Path: %#", localizedPath);
if(data) {
NSError *writingError;
BOOL wasWritten = [data writeToFile:localizedPath options:NSDataWritingAtomic error:&writingError];
if(!wasWritten) {
NSLog(#"%#", [writingError localizedDescription]);
}
}
Now, this creates a plist file that I can see and read on the file system. When I try to use the following to unarchive it though:
NSError *error;
NSString *directory = [self getPlistFilePath];
NSArray *files = [[NSFileManager defaultManager]contentsOfDirectoryAtPath:directory error:&error];
NSMutableArray *characters = [[NSMutableArray alloc]init];
for(NSString *path in files) {
if(![path hasSuffix:#"plist"]) {
continue;
}
NSString *fullPath = [directory stringByAppendingPathComponent:path];
NSData *data = [NSData dataWithContentsOfFile:fullPath];
IRSkillsObject *object = [NSKeyedUnarchiver unarchiveObjectWithData:data]; // get EXEC_BAD_ACCESS here...
[data release];
[characters addObject:object];
}
I get an EXEC_BAD_ACCESS error.
The IRSkillsObject conforms to the NSCoding protocol. You can see, I commented the line that I get the error on.
I am sure it's something I am doing wrong, but I just can't see it. I have tried to step through with the debugger (placing a break point in the initWithCoder: method of the object) but I don't get any errors then. In fact, it places the data in the object properly as I watch. But once it's done loading the data, it gives the error. I have tried using the retain method, but that doesn't help.
Any help that you can provide would be greatly appreciated!

You are releasing data without allocating it.
NSData *data = [NSData dataWithContentsOfFile:fullPath];
IRSkillsObject *object = [NSKeyedUnarchiver unarchiveObjectWithData:data];
[data release];
So try this:
NSData *data = [[NSData alloc] initWithContentsOfFile:fullPath];
IRSkillsObject *object = [NSKeyedUnarchiver unarchiveObjectWithData:data];
[data release];

When an EXEC_BAD_ACCESS error is found. Usually is because some data has been released but it is still needed in the code.
Maybe there is a property inside your IRSkillsObject not retained in -initWithCoder:

Related

Creating a plist with multiple strings

I have a multiple strings I would like to write to one plist using objective c. Can anyone please tell me exactly how to do this? I appreciate it
As H2CO3 hinted, you could use NSArray's writeToFile:atomically: method.
For example:
NSArray *arr = #[
#"my first string",
#"my second string",
#"and the last one"
];
[arr writeToFile:#"./out.plist" atomically:NO]; // Or YES depending on your needs
Here's one possibility:
// Create the path that you want to write your plist to.
NSError *error = nil;
NSURL *documentsURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:YES error:&error];
if (documentsURL == nil) {
NSLog(#"Error finding user documents in directory: %#", [error localizedDescription]);
return nil;
}
NSString *path = [[documentsURL path] stringByAppendingPathComponent:#"YourFile.plist"];
// Populate your strings and save to the plist specified in the above path.
NSString *kRoot = #"kRoot";
NSMutableDictionary *tempDict = [NSMutableDictionary dictionary];
tempDict[kRoot] = [NSMutableArray array];
[tempDict[kRoot] addObject:#"String 1"];
[tempDict[kRoot] addObject:#"String 2"];
[tempDict[kRoot] addObject:#"String 3"];
// Etc, add all your strings
if (![tempDict writeToFile:path atomically:YES])
{
NSLog(#"Error writing data to path %#", path);
}

How to save data locally in app? [duplicate]

This question already has answers here:
Working with data in iOS Apps (What to choose? NSData, CoreData, sqlite, PList, NSUserDefaults)
(2 answers)
Closed 9 years ago.
I've been struggling with this for ages now and I really need some good help here. :)
I have an app where I'm parsing a quite big JSON into appdelegate's didFinishLaunchingWithOptions.
My Model Objects are:
Tab:
NSString *title
NSMutableArray *categories
Category:
NSString *title
NSMutableArray *items
Item
NSString *title
NSString *description
UIImage *image
I need to save the data locally, cause the parsing takes about 15 seconds every time my app starts. I'm using the SBJSON framework.
Here's my code for parsing:
NSString *filePath = [[NSBundle mainBundle] pathForResource:#"json_template" ofType:#"json"];
NSString *contents = [NSString stringWithContentsOfFile: filePath encoding: NSUTF8StringEncoding error: nil];
SBJsonParser *jsonParser = [[SBJsonParser alloc] init];
NSMutableDictionary *json = [jsonParser objectWithString: contents];
tabs = [[NSMutableArray alloc] init];
jsonParser = nil;
for (NSString *tab in json)
{
Tab *tabObj = [[Tab alloc] init];
tabObj.title = tab;
NSDictionary *categoryDict = [[json valueForKey: tabObj.title] objectAtIndex: 0];
for (NSString *key in categoryDict)
{
Category *catObj = [[Category alloc] init];
catObj.name = key;
NSArray *items = [categoryDict objectForKey:key];
for (NSDictionary *dict in items)
{
Item *item = [[Item alloc] init];
item.title = [dict objectForKey: #"title"];
item.desc = [dict objectForKey: #"description"];
item.url = [dict objectForKey: #"url"];
if([dict objectForKey: #"image"] != [NSNull null])
{
NSURL *imgUrl = [NSURL URLWithString: [dict objectForKey: #"image"]];
NSData *imageData = [NSData dataWithContentsOfURL: imgUrl];
item.image = [UIImage imageWithData: imageData];
}
else
{
UIImage *image = [UIImage imageNamed: #"standard.png"];
item.image = image;
}
[catObj.items addObject: item];
}
[tabObj.categories addObject: catObj];
}
[tabs addObject: tabObj];
}
What is the best way of doing this? Using Core Data or NSFileManager?
If you have som code example too it will make me very happy.
This is the last thing i need to fix before the app is ready for app store and it just kills me! I can't solve this problem.
If you are working on iOS then you save a file to the Documents folder. On Mac OS X it would be in the Application Support folder. Since you are on iOS, read this answer for how to access the Documents folder.
All of the objects that you want to store should implement NSCoding. The above variables already do. Should you want to store the tabs, categories and items directly they would need to implement NSCoding. Then all you need is to serialize them to a file. When opening you app you can look for this file and get your objects back without parsing.
The code should look something like this (untested and error checking is ommited for brevity):
- (void) saveStateToDocumentNamed:(NSString*)docName
{
NSError *error;
NSFileManager *fileMan = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docPath = [paths[0] stringByAppendingPathComponent:docName];
if ([fileMan fileExistsAtPath:docPath])
[fileMan removeItemAtPath:docPath error:&error];
// Create the dictionary with all the stuff you want to store locally
NSDictionary *state = #{ ... };
// There are many ways to write the state to a file. This is the simplest
// but lacks error checking and recovery options.
[NSKeyedArchiver archiveRootObject:state toFile:docPath];
}
- (NSDictionary*) stateFromDocumentNamed:(NSString*)docName
{
NSError *error;
NSFileManager *fileMan = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docPath = [paths[0] stringByAppendingPathComponent:docName];
if ([fileMan fileExistsAtPath:docPath])
return [NSKeyedUnarchiver unarchiveObjectWithFile:docPath];
return nil;
}

parse JSON in objectiveC (SBJSON) objects and arrays

So far I've discovered in JSON that everything enclosed in { } are objects (objC : NSDictionary) and anything enclosed in [ ] is an array (objC : NSArray).
I've read and re-read this article about the subject>
How to parse JSON into Objective C - SBJSON
I have a .json file with the data modeled like this:
http://elbee101.com/dummySchedule.json
...and now for the code:
SBJSON *parser = [[SBJSON alloc] init];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:#"http://elbee101.com/dummySchedule.json"]];
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *json_string = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];
NSDictionary *schedule = [parser objectWithString:json_string error:nil];
NSDictionary *day = [schedule objectForKey:#"day"];
NSArray *myList = [day objectForKey:#"name"];
NSLog(#"myList %#", myList);
NSArray *numLaps = [myList objectAtIndex:0];
NSLog(#"numlaps%# ", numLaps);
I'm getting "myList (null)" and "numlaps (null)" from the above code?!#
The question: Can somebody please set me straight on the ordering of objects and arrays with respect to my json data? I want to drill down the tree so that I can access the 'day name', 'session starttime/endtime/sessionname', 'numlaps' & 'class' but I can't seem to get past the 'day' object/array(?)
What you're referring to as schedule is the object enclosed in the outermost {}. Try this:
NSDictionary *json = [parser objectWithString:json_string error:nil];
NSDictionary *schedule = [json objectForKey:#"schedule"];
Then continue as before.
Also, if you're on iOS 5 you can use the NSJSONSerialization class -- using it is pretty much the same, you might get better performance, and you don't have to worry about the hassles of using a third-party library.
call this where ever u need to parse
NSMutableArray *arr=[[NSMutableArray alloc] init];
arr=[[Headparse getArrayFromUrl:#"http://elbee101.com/dummySchedule.json"] retain];
NSLog(#"%#",[arr description]);
[arr release];
write this method as custom class use when ever you need
+(NSMutableArray *) getArrayFromUrl: (NSString *)actionType
{
NSMutableData *responseData1= [NSMutableData data] ;
responseData1 = [NSMutableData dataWithContentsOfURL:[NSURL URLWithString:actionType]];
// NSLog(#"%#",responseData1);
NSString *responseString1 = [[NSString alloc] initWithData:responseData1 encoding:NSUTF8StringEncoding];
//NSLog(#"REs:-->%#",responseString1);
//[responseData1 release];
responseData1 = nil;
NSMutableArray *responseArray = [[NSMutableArray alloc]init];
responseArray = (NSMutableArray *)[responseString1 JSONValue];
// NSLog(#"ghfchfvghv%#",responseArray);
[responseString1 release];
return responseArray;
}
This is how i use NSJsonSerialization for parsing the json object.
NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:#"http://elbee101.com/dummySchedule.json"]];
NSError *err;
NSDictionary* json = [NSJSONSerialization
JSONObjectWithData:data
options:kNilOptions
error:&err]; //
NSDictionary *schedule_dict = [json objectForKey:#"schedule"];
NSArray *days = [schedule_dict objectForKey:#"day"];//Days Array from day Object
NSDictionary *dayOne = [days objectAtIndex:0];
NSDictionary *dayTwo = [days objectAtIndex:1];
NSLog(#"THE DAY ONE : %#",dayOne);
NSLog(#"THE DAY TWO : %#",dayTwo);
Hope this may help you ....Note : If you don't want to go with NSJsonSerailization(consider reading of this) ,but still the parsing of json data like above will applicable in your case too.

Memory leak in NSMutableArray, can't autorelease

I am having trouble releasing tempArray below... tempArray is a leak and I have tried return [tempArray autorelease] and it causes a crash. Does anyone know how to get rid of the memory leak in tempArray?
+(NSMutableArray*) returnTheArray:(NSString*)thePath forTheKey:(NSString*)theKey {
NSString *errorDesc = nil;
NSPropertyListFormat format;
NSString *plistPath;
NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES) objectAtIndex:0];
NSString *testString = [thePath stringByAppendingString:#".plist"];
plistPath = [rootPath stringByAppendingPathComponent:testString];
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath]) {
plistPath = [[NSBundle mainBundle] pathForResource:thePath ofType:#"plist"];
}
NSData *plistXML = [[NSFileManager defaultManager] contentsAtPath:plistPath];
NSDictionary *temp = (NSDictionary *)[NSPropertyListSerialization
propertyListFromData:plistXML
mutabilityOption:NSPropertyListMutableContainersAndLeaves
format:&format
errorDescription:&errorDesc];
if (!temp) {
CCLOG(#"Error reading plist: %#, format: %d", errorDesc, format);
}
NSMutableArray *tempArray = [[NSMutableArray alloc] initWithArray:[temp objectForKey:theKey]];
return tempArray;
}
Well, the problem is that returnTheArray is not a name that the Analyzer will recognize as returning a retained value -- this is why it complains. So either you rename the method or return an autoreleased value. But if the latter you need to make sure that the "consumer" of the returned value appropriately deals with it -- retaining it if the value must persist beyond the next autorelease pool drain operation.
try:
NSMutableArray *tempArray = [NSMutableArray arrayWithArray:[temp objectForKey:theKey]];

Objective-C Memory Management Alchemistry: Code causes a leak after being put in a class

I came to Objective-C from C++ so I still sometimes has problems understanding memory management of Objective-C. I have a following problem now - XCode Analyzer tells me that object *data causes leaks further in code.
- (void)loadSettings
{
NSString *filePath = [self dataFilePath];
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath])
{
NSData *data = [[NSMutableData alloc]
initWithContentsOfFile:[self dataFilePath]];
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc]
initForReadingWithData:data];
// object *data is no longer referenced at this point and has a retain count of +1 (object leaked)
AppData *settingsData = [unarchiver decodeObjectForKey:kDataKey];
if (nil != settingsData)
{
customerVoiceActive = settingsData.customerVoice;
}
[unarchiver finishDecoding];
[unarchiver release];
[settingsData release];
}
}
What drives me crazy is that exactly the same code (except naming) perfectly works and causes no leaks, being placed in applicationDidFinishLaunching:
//load app data
NSString *filePath = [self dataFilePath];
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
NSData *data = [[NSMutableData alloc]
initWithContentsOfFile:[self dataFilePath]];
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc]
initForReadingWithData:data];
AppData *appData = [unarchiver decodeObjectForKey:kDataKey];
bCustomerVoice=appData.customerVoice;
[unarchiver finishDecoding];
[unarchiver release];
[data release];
}
What's the difference?
In code sample 1) you release settingsData, while in codesample 2) you are releasing data . Changing that line should solve your issue.
You forgot to release NSData *data.
Add the following line after [settingsData release];:
[data release];
The "exact same" code contains an extra line:
[data release];
settingsData should NOT be released, because it was not obtained through a method that implies that you own the returned object. However, you MUST release data, because you allocated it yourself, and this implies ownership.