I've been following this guide on saving data to a plist, using NSCoding. I've followed the guide step by step as far as i can tell, as well as looked at the sample code, but when it comes to actually saving the data, it doesn't seem to save it, nor does it seem to call the save function. I'm calling the save function via a button:
- (IBAction)saveAll:(id)sender {
NSLog(#"start saveall");
_conosirDoc.data.wineType = _wineType.text;
_conosirDoc.data.wineTitle = _wineTitle.text;
_conosirDoc.data.wineYear = _wineYear.text;
_conosirDoc.data.wineVolume = _wineVolume.text;
_conosirDoc.data.wineRating = _wineRating.text;
_conosirDoc.data.wineCountry = _wineCountry.text;
_conosirDoc.data.wineRegion = _wineRegion.text;
_conosirDoc.data.wineGrapes = _wineGrapes.text;
[_conosirDoc saveData];
NSLog(#"%#", _conosirDoc.data.wineType);
NSLog(#"end saveall");
}
so when the button is clicked the log reads :
start saveall
(null)
end saveall
so from there I set up the following NSLog's in the saveData function:
- (void)saveData {
NSLog(#"being called?");
if (_data == nil) return;
NSLog(#"START");
[self createDataPath];
NSLog(#"END");
NSString *dataPath = [_docPath stringByAppendingPathComponent:kDataFile];
NSLog(#"%#", dataPath);
NSMutableData *data = [[NSMutableData alloc] init];
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[archiver encodeObject:_data forKey:kDataKey];
[archiver finishEncoding];
[data writeToFile:dataPath atomically:YES];
}
and from this, none of these NSLogs appear in the output, and i can't work out why it's not being called properly. Let me know if you need anymore information.
Thanks.
The log lines that you see (and especially the ones that you do not see) indicate that _conosirDoc is nil - it has not been initialized: the only reason the saveData would not log the unconditional "being called?" is that saveData is invoked on a nil. In all other cases there would be at least that additional log line.
You need to add code that assigns an object to your _conosirDoc variable to make it work:
_conosirDoc = [[ConosirDocType alloc] init];
Replace ConosirDocType above with the actual type of _conosirDoc.
Related
Currently, I have a class that is parsing XML and sending the dictionary that the XML is parsed to to a view controller.
Here is a snippet of the code that sends the dictionary to the other class (where "response" is the dictionary):
if ([elementName isEqualToString:#"SessionData"])
{
// We reached the end of the XML document
// dumps dictionary into log
NSLog(#"Dump:%#", [response description]);
// sends dictionary to the VC
CardSetupViewController *setup = [[CardSetupViewController alloc]init];
setup.response = self.response;
//checks
NSLog(#"%# lololololol", [setup.response description]); //THIS WORKS FINE!!
return;
}
At that point, the code works fine. That NSLog marked with //THIS WORKS FINE!! works... obviously. Here is the method in the ViewController:
- (BOOL)authorize //this
{
AddCard *addCard = [[AddCard alloc]init];
ServerConnection *connection = [[ServerConnection alloc]init];
//XMLParser *xmlParser = [[XMLParser alloc]initXMLParser];
//serverReturn posts the data and is the ACTUAL server response in NSData form
NSData *serverReturn = [connection postData:[addCard textBoxToXml:
[self nameOnCardGet]:
[self ccNumGet]:
[self expMoGet]:
[self expYrGet]:
[self cvvGet]:
[self zipGet]:
[self nickNameGet]:
[self pinGet]]];
//This takes the information from the server and parses it to "response"
//Creates and inits NSXMLParser Object
NSXMLParser *nsXmlparser = [[NSXMLParser alloc] initWithData:serverReturn];
//Create and init our delegate
XMLParser *parser = [[XMLParser alloc] initXMLParser];
//set delegate
[nsXmlparser setDelegate:(id <NSXMLParserDelegate>) parser];
//initiates self.response THIS MAY NOT BE NEEDED
//response = [[NSMutableDictionary alloc]init];
//parsing
BOOL success = [nsXmlparser parse];
//error catch testing
if (success) {
NSLog(#"No errors");
}
else {
NSLog(#"Error parsing document!");
}
//dump
NSLog(#"ZOMG CHECK DIS OUT%#", [response description]);
return NO;
}
Basically, the NSLog that states "ZOMG CHECK DIS OUT" is returning (null) and I can't figure out why. No compilation errors, it is a property/synthesize as well. Any ideas?
Thanks in advance. Oh, and please excuse my NSLog comments. I had to differentiate from different parts of the code, and I was in a good mood.
Edit: I am using Automatic Reference Counting. Don't worry, nothing is leaking.
In your first code block, you generate a CardSetupViewController and then leak it. It is unrelated to whatever object is running the second code block. I assume that your second view controller is from your NIB?
Note that you're also leaking your NSXMLParser.
Your [response description], whatever that is, is probably an autoreleased object that gets released before ZOMG CHECK DIS OUT. Retain it and see if that works. Don't forget to release it when you're done with it.
I have a strange issue, when it comes to parsing XML with NSXMLParser on the iPhone. When starting the app, I want to preload 4 table-views, that are populated by RSS-Feeds in the background.
When I init the table-views one-by-one, than loading, parsing and displaying all works like a charm. But when I try to init all view at once (at the same time), than it seems, that the XML-parser-instances are disturbing each other. Somehow data from one XML-Feed are "broadcasted" into other xml-parser instances, where they do not belong. Example: there is a "teammember" item, with "This is my name". When this bug occurs, there is a string from another xml-feed added, i.e. resulting in: "This is my name58", where 58 is the chart-position of something from the other view. "58" seems to miss then on the other instance.
It looks to me, that this bug occurs because of the NSXMLParser-delegate method:
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {
if (!currentStringValue) {
currentStringValue = [[NSMutableString alloc] initWithCapacity:50];
}
[currentStringValue appendString:string];
}
In this case "by coincidence" bytes are appended to strings, where they do not belong to.
The strange thing is, that every instance of NSXMLParser is unique, got its own unique delegates, that are attached to their own ViewController. Every parsing-requests spawns it own background-task, with its own (also also unique named) Autorelease-pool.
I am calling the NSXMLParser like this in the ViewController:
// prepare XML saving and parsing
currentStringValue = [[[NSMutableString alloc] initWithCapacity:50] retain];
charts = [[NSMutableArray alloc] init];
NSURL *url = [[NSURL alloc] initWithString:#"http://(SOME XML URL)"];
xmlParser = [[[NSXMLParser alloc] initWithContentsOfURL:url] retain];
//Set delegate
[xmlParser setDelegate:self];
//loading indicator
progressWheel = [[[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(150.0,170.0,20.0,20.0)] autorelease];
progressWheel.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray;
[self.view addSubview:progressWheel];
[progressWheel startAnimating];
// start loading and parsing the xml-feed in the background
//[self performSelectorInBackground:#selector(parse:) withObject:xmlParser]; -> I also tried this
[NSThread detachNewThreadSelector:#selector(parse:) toTarget:self withObject:xmlParser];
And this is one of the background-tasks, parsing the feed:
-(void)parse:(NSXMLParser*)myParser {
NSAutoreleasePool *schedulePool = [[NSAutoreleasePool alloc] init];
BOOL success = [myParser parse];
if(success) {
NSLog(#"No Errors. xmlParser got: %#", myParser);
(POST-PROCESSING DETAILS OF THE DATA RETURNED)
[self.tableView reloadData];
} else {
NSLog(#"Couldn't initalize XMLparser");
}
[progressWheel stopAnimating];
[schedulePool drain];
[myParser release];
}
What could cause this issue? Am I calling the background-task in the right way? Why is this bug approaching, since every XML-Parser got its own, unique instance?
You should not be updating UI elements (like progressWheel) from inside a background thread. UI updates should be done on the main thread.
Use -performSelectorOnMainThread:withObject:waitUntilDone: to update UI elements from within a background thread.
I've released an open source RSS/Atom Parser for iPhone and it makes reading and parsing web feeds extremely easy.
You can set it to download the data asynchronously, or you could run it in a background thread synchronously to collect the feed data.
Hope this helps!
I'm working on a homework app that uses custom Assignment objects for each assignment. I am trying to store an NSMutableArray (casted to an NSArray via initWithArray:) in standardUserDefaults but I'm having trouble with saving and reloading the array.
I have a table view from which you can choose to add a new assignment (which loads NewAssignmentViewController). When you save the assignment, it is pushed back to an array in AssigmentsViewController. And then you call it every time you load the UITableView which shows the assignments.
Here is the relating code:
-(void)saveToUserDefaults:(NSArray*)myArray{
NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
if (standardUserDefaults) {
[standardUserDefaults setObject:[NSKeyedArchiver archivedDataWithRootObject:myArray] forKey:#"Assignments"];
[standardUserDefaults synchronize];
}
}
-(void)retrieveFromUserDefaults{
NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];
NSData *dataRepresentingSavedArray = [currentDefaults objectForKey:#"Assignments"];
if (dataRepresentingSavedArray != nil) {
NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:dataRepresentingSavedArray];
if ([oldSavedArray count] != 0) {
[assignments setArray:[[NSMutableArray alloc] initWithArray:oldSavedArray]];
}
else {
assignments = [[NSMutableArray alloc] initWithCapacity:100];
}
}
}
-(void)backButtonPressed {
[self saveToUserDefaults:[[NSArray alloc] initWithArray:assignments]];
[self.navigationController popViewControllerAnimated:YES];
}
Please help. It does not load the array but does not give any error. Any tips about UserDefault or KeyedArchiver in general would be greatly appreciated.
Couple of things here:
If I understand you correctly, you're trying store an array whose contents are the assignment objects.
If you want to serialize these objects for storage into NSUserDefaults, the Assignment objects themselves need to conform the NSCoding protocol by overriding these methods:
- (void)encodeWithCoder:(NSCoder *)encoder;
- (id)initWithCoder:(NSCoder *)decoder;
Since you didn't post the code for your Assignment objects, dunno if you did this properly or at all. If you have you should be able to encode the object. See the Archives and Serializations Programming Guide for more.
As for NSUserDefaults, by my read, you're basically trying to store your application's object model there. Not the best idea. NSUserDefaults is best suited for use with light-weight persistent data: basic preferences, strings, scraps of universal data.
What I would do is write out your archived data to a file and load it when your view loads.
Here's some code from Beginning iPhone Development on that subject:
Creating an archive from an object or objects that conforms to NSCoding is relatively easy. First, we create an instance of NSMutableData to hold the encoded data and then create an NSKeyedArchiver instance to archive objects into that NSMutableData instance:
NSMutableData *data = [[NSMutableData alloc] init];
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
After creating both of those, we then use key-value coding to archive any objects we wish to include in the archive, like this:
[archiver encodeObject:myObject forKey:#”keyValueString”];
Once we’ve encoded all the objects we want to include, we just tell the archiver we’re done, write the NSMutableData instance to the file system, and do memory cleanup on our objects.
[archiver finishEncoding]; BOOL success = [data writeToFile:#”/path/to/archive” atomically:YES];
[archiver release];
[data release];
To reconstitute objects from the archive, we go through a similar process. We create an NSData instance from the archive file and create an NSKeyedUnarchiver to decode the data:
NSData *data = [[NSData alloc] initWithContentsOfFile:path];
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
After that, we read our objects from the unarchiver using the same key that we used to archive the object:
self.object = [unarchiver decodeObjectForKey:#”keyValueString”];
You'd also need to get your application's documents directory to save and load the files.
It's a wildly useful book, full of drop in code snippets. The chapter on persistence might be helpful for you. You might be much happier using Core Data for this task, come to think of it.
I'm not sure if this will fix your problem, but you don't have to pull the array out of Defaults as NSData. Check the NSUserDefaults reference and you'll see that Arrays are valid default objects.
I need to save my own created class to file, I found on the internet, that good approach is to use NSKeyedArchiver and NSKeyedUnarchiver
My class definition looks like this:
#interface Game : NSObject <NSCoding> {
NSMutableString *strCompleteWord;
NSMutableString *strWordToGuess;
NSMutableArray *arGuessedLetters; //This array stores characters
NSMutableArray *arGuessedLettersPos; //This array stores CGRects
NSInteger iScore;
NSInteger iLives;
NSInteger iRocksFallen;
BOOL bGameCompleted;
BOOL bGameOver;
}
I've implemented methods initWithCoder: and encodeWithCoder: this way:
- (id)initWithCoder:(NSCoder *)coder
{
if([coder allowsKeyedCoding])
{
strCompleteWord = [[coder decodeObjectForKey:#"CompletedWord"] copy];
strWordToGuess = [[coder decodeObjectForKey:#"WordToGuess"] copy];
arGuessedLetters = [[coder decodeObjectForKey:#"GuessedLetters"] retain];
// arGuessedLettersPos = [[coder decodeObjectForKey:#"GuessedLettersPos"] retain];
iScore = [coder decodeIntegerForKey:#"Score"];
iLives = [coder decodeIntegerForKey:#"Lives"];
iRocksFallen = [coder decodeIntegerForKey:#"RocksFallen"];
bGameCompleted = [coder decodeBoolForKey:#"GameCompleted"];
bGameOver = [coder decodeBoolForKey:#"GameOver"];
}
else
{
strCompleteWord = [[coder decodeObject] retain];
strWordToGuess = [[coder decodeObject] retain];
arGuessedLetters = [[coder decodeObject] retain];
// arGuessedLettersPos = [[coder decodeObject] retain];
[coder decodeValueOfObjCType:#encode(NSInteger) at:&iScore];
[coder decodeValueOfObjCType:#encode(NSInteger) at:&iLives];
[coder decodeValueOfObjCType:#encode(NSInteger) at:&iRocksFallen];
[coder decodeValueOfObjCType:#encode(BOOL) at:&bGameCompleted];
[coder decodeValueOfObjCType:#encode(BOOL) at:&bGameOver];
}
return self;
}
- (void)encodeWithCoder:(NSCoder *)coder
{
if([coder allowsKeyedCoding])
{
[coder encodeObject:strCompleteWord forKey:#"CompleteWord"];
[coder encodeObject:strWordToGuess forKey:#"WordToGuess"];
[coder encodeObject:arGuessedLetters forKey:#"GuessedLetters"];
//[coder encodeObject:arGuessedLettersPos forKey:#"GuessedLettersPos"];
[coder encodeInteger:iScore forKey:#"Score"];
[coder encodeInteger:iLives forKey:#"Lives"];
[coder encodeInteger:iRocksFallen forKey:#"RocksFallen"];
[coder encodeBool:bGameCompleted forKey:#"GameCompleted"];
[coder encodeBool:bGameOver forKey:#"GameOver"];
}
else
{
[coder encodeObject:strCompleteWord];
[coder encodeObject:strWordToGuess];
[coder encodeObject:arGuessedLetters];
//[coder encodeObject:arGuessedLettersPos];
[coder encodeValueOfObjCType:#encode(NSInteger) at:&iScore];
[coder encodeValueOfObjCType:#encode(NSInteger) at:&iLives];
[coder encodeValueOfObjCType:#encode(NSInteger) at:&iRocksFallen];
[coder encodeValueOfObjCType:#encode(BOOL) at:&bGameCompleted];
[coder encodeValueOfObjCType:#encode(BOOL) at:&bGameOver];
}
}
And I use these methods to archive and unarchive data:
[NSKeyedArchiver archiveRootObject:currentGame toFile:strPath];
Game *currentGame = [NSKeyedUnarchiver unarchiveObjectWithFile:strPath];
I have two problems.
1) As you can see, lines with arGuessedLettersPos is commented, it's because every time I try to encode this array, error comes up(this archiver cannot encode structs), and this array is used for storing CGRect structs.
I've seen solution on the internet. The thing is, that every CGRect in the array is converted to an NSString (using NSStringFromCGRect()) and then saved. Is it a good approach?
2)This is bigger problem for me. Even if I comment this line and then run the code successfully, then save(archive) the data and then try to load (unarchive) them, no data is loaded. There aren't any error but currentGame object does not have data that should be loaded.
Could you please give me some advice? This is first time I'm using archivers and unarchivers.
Thanks a lot for every reply.
The problem with loading and saving solved another way...
Instead of implementing - (id)initWithCoder:(NSCoder )coder and - (void)encodeWithCoder:(NSCoder)coder I used this solution:
NSMutableData *data = [NSMutableData alloc];
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[archiver encodeObject:self.strCompleteWord forKey:#"CompleteWord"];
[archiver encodeObject:self.strWordToGuess forKey:#"WordToGuess"];
[archiver encodeObject:self.arGuessedLetters forKey:#"GuessedLetters"];
//[coder encodeObject:self.arGuessedLettersPos forKey:#"GuessedLettersPos"];
[archiver encodeInteger:self.iScore forKey:#"Score"];
[archiver encodeInteger:self.iLives forKey:#"Lives"];
[archiver encodeInteger:self.iRocksFallen forKey:#"RocksFallen"];
[archiver encodeBool:self.bGameCompleted forKey:#"GameCompleted"];
[archiver encodeBool:self.bGameOver forKey:#"GameOver"];
[archiver finishEncoding];
[data writeToFile:strPath atomically:YES];
[data release];
and
NSMutableData *data = [[NSMutableData alloc] initWithContentsOfFile:strPath];
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
self.strCompleteWord = [[unarchiver decodeObjectForKey:#"CompletedWord"] copy];
self.strWordToGuess = [[unarchiver decodeObjectForKey:#"WordToGuess"] copy];
self.arGuessedLetters = [[unarchiver decodeObjectForKey:#"GuessedLetters"] retain];
//self.arGuessedLettersPos = [[unarchiver decodeObjectForKey:#"GuessedLettersPos"] retain];
self.iScore = [unarchiver decodeIntegerForKey:#"Score"];
self.iLives = [unarchiver decodeIntegerForKey:#"Lives"];
self.iRocksFallen = [unarchiver decodeIntegerForKey:#"RocksFallen"];
self.bGameCompleted = [unarchiver decodeBoolForKey:#"GameCompleted"];
self.bGameOver = [unarchiver decodeBoolForKey:#"GameOver"];
[unarchiver finishDecoding];
[data release];
And this works totally fine :)
I might be missing it, but I don't see any obvious bugs in this code.
Here are some ideas that might help:
Add some NSLog statements, and watch the debug output (open with command-shift-R in xcode) to see if your encode/decode methods are actually being called.
Check that the archive file is saved: Running in the simulator, you can save to any local path you want, such as /tmp/my_archive_file. Try to save to that file, and see if (a) the file exists with the right timestamp, and (b) you print out the file, you can see some recognizable strings (like "RocksFallen") in amongst the binary gooblygoo.
I also don't think it's necessary to check for allowsKeyed(En)coding since you know that's always going to be true when you're explicitly using NSKeyed(Un)archiver to do your dirty work for you. So you can throw away the other half of your code.
About coding those arrays of CGRects: I don't think you can directly add structs to an NSMutableArray, right? So they must be some kind of object, which means you can add NSCoding support to that object. If it's not your own object, you can subclass it and add that protocol, or try adding it as a category.
Thanks for reply Tyler.
I looked in the saved file and there are recognizable strings like RocksFallen and so on, also there are some recognizable values that might be saved in string variables.. So this seems to be good.
I tried to put some NSLogs in the code and not everything seems to be good. So...
When I launch simulator for the first time, there's no archive file, yes it is obvious, because nothing is saved. Then I change something and exit the application. When the application is being terminated, data might be archived, everything's fine. NSLog statements are written in the console, file is on the disk. But what is strange is that when I launch the application then, decode method(initwithcoder) is not being called.. Don't know why. Then I exit the simulator and run the simulator again. When I run it again, decode method is being called at the launchtime. But only at the first launchtime after running simulator, when I then work with simulator like exit the app and run it again, initWithCoder method is not being called and that's very strange for me..
So there are problems unarchiving it i think.
The best way to archive structs (that are not holding any pointers) with would be to wrap the values in an NSData block.
here, i'm dumping a struct array to the archiver:
for (int i = 0; i < items; i++) {
NSString *keyValue = [NSString stringWithFormat:#"YourStruct%i", i ];
NSData *dataset = [NSData dataWithBytes:(void*)&activeprofile[i] length:(sizeof(profileset))];
[encoder encodeObject:dataset forKey:keyValue]; // makes a nice, solid data block
}
and reading the data back in:
for (int i = 0; i < items; i++) {
NSString *keyValue = [NSString stringWithFormat:#"YourStruct%i", i ];
NSData *dataset = [decoder decodeObjectForKey:keyValue];
[dataset getBytes:&activeprofile[i] length:sizeof(profileset)];
}
There you have it: easy as pie and extremely flexible with datatypes!
A similar method for non-keyed archiving can be found here: http://borkware.com/quickies/one?topic=NSCoder Though I suggest sticking with keyed archiving, as NSArchive is not supported on the iPhone and has been classified as legacy code.
Everything is working fine until I call the saveFile method (shown below) to write the file back to disk, where it crashes. What am I doing wrong?
This is part of my viewDidLoad method where I open the file, which works fine.
//Get The Path
[self initPath];
dictionary = [[NSMutableDictionary alloc] initWithContentsOfFile:accountsFilePath];
if (accountsArray == nil) {
accountsArray = [[[NSMutableArray alloc]init] autorelease];
}
if (countArray == nil) {
countArray = [[[NSMutableArray alloc]init] autorelease];
}
countArray = [dictionary objectForKey:#"count"];
accountsArray = [dictionary objectForKey:#"username"];
Then I load it into a tableview. I then add some new items to it, which works fine. Then I call this method to save it and it crashes:
-(void)saveFile {
[dictionary setObject:accountsArray forKey:#"username"];
[dictionary setObject:countArray forKey:#"count"];
[dictionary writeToFile:accountsFilePath atomically:YES];
}
You are autoreleasing countArray and accountsArray just after initializing them. Thet may well be already released when you try to save them. Try commenting the autorelease for both of them (and remember to release them somewhere, maybe in the dealloc method).
// what if the path is not found, file is not load and in turn dictionary is nil
dictionary = [[NSMutableDictionary alloc] initWithContentsOfFile:accountsFilePath];
// first time you create accountsArray, countArray
if (accountsArray == nil) {
accountsArray = [[[NSMutableArray alloc]init] autorelease]; }
if (countArray == nil) {
countArray = [[[NSMutableArray alloc]init] autorelease]; }
// hey why you assign accountsArray to a new one again, what about the old one you just init?
// if dictionary is nil, countarray will be nil too
countArray = [dictionary objectForKey:#"count"];
accountsArray = [dictionary objectForKey:#"username"];
////
////
////////////////////////////////////////////////////////////////
what is your crash message?
what is your accountsFilePath
can you read the dictionary file?
one thing you may want to know
writeToFile will not create a new folder for you
so all folder in accountsFilePath is a must to be exist.
otherwise you may want to create that folder using nsfilemanager
Are all your variables in scope? I assume accountsFilePath and dictionary are class variables? If not they might die at the end of viewDidLoad.
The other thing that might bite you is the capacity of your dictionary is too small, or that the iPhone doesn't like you using the setObject method to overwrite key/value pairs like that. Perhaps try calling removeObjectForKey: and then add it back as you have above?
You probably already did this, but I would inspect dictionary and accountsFilePath in gdb or by using NSLog right before the writeToFile:atomically: call.
You also might want to share more surrounding code to show what else is going on with respect to this dictionary.
I've been using NSZombie with much success for debugging random crashes as well.