assign value from NSDictionary to NSManagedObject - objective-c

My app requires to get data from a .Net WCF service when the device is connected to WiFi.If there's a new row added on the server,it should add it to its CoreData database. I am using a NSDictionary for comparing the local objects with the remote objects. The code is:
-(void)handleGetAllCategories:(id)value
{
if([value isKindOfClass:[NSError class]])
{
NSLog(#"This is an error %#",value);
return;
}
if([value isKindOfClass:[SoapFault class]])
{
NSLog(#"this is a soap fault %#",value);
return;
}
NSMutableArray *result = (NSMutableArray*)value;
NSMutableArray *remoteObj = [[NSMutableArray alloc]init];
for (int i = 0; i < [result count]; i++)
{
EDVCategory *catObj = [[EDVCategory alloc]init];
catObj = [result objectAtIndex:i];
[remoteObj addObject:catObj];
}
NSArray *remoteIDs = [remoteObj valueForKey:#"categoryId"];
NSFetchRequest *request = [[[NSFetchRequest alloc] init]autorelease];
request.predicate = [NSPredicate predicateWithFormat:#"categoryId IN %#", remoteIDs];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Categories" inManagedObjectContext:__managedObjectContext];
[request setEntity:entity];
NSMutableArray *results = [[NSMutableArray alloc]initWithArray:[__managedObjectContext executeFetchRequest:request error:nil]];
NSArray *existingIDs = [results valueForKey:#"categoryId"];
NSDictionary *existingObjects = [NSDictionary dictionaryWithObjects:results forKeys:existingIDs];
for (NSDictionary *remoteObjectDic in remoteObj)
{
Categories *existingObject = [existingObjects objectForKey:[remoteObjectDic valueForKey:#"categoryId"]];
if (existingObject)
{
NSLog(#"object exists");
}
else
{
NSLog(#"create new local object");
// Categories *newCategory;
// newCategory = [NSEntityDescription insertNewObjectForEntityForName:#"Categories" inManagedObjectContext:__managedObjectContext];
// [newCategory setCategoryId:[NSNumber numberWithInt:[[remoteObjectDic objectForKey:#"categoryId"]intValue]]];
// [newCategory setCategoryName:[remoteObjectDic objectForKey:#"categoryName"]];
// [newCategory setDocCount:[NSNumber numberWithInt:[[remoteObjectDic objectForKey:#"docCount"]intValue]]];
// [newCategory setCategoryType:[NSNumber numberWithInt:[[remoteObjectDic objectForKey:#"categoryType"]intValue]]];
// [newCategory setSubCategoryId:[NSNumber numberWithInt:[[remoteObjectDic objectForKey:#"subCategoryId"]intValue]]];
// [__managedObjectContext insertObject:newCategory];
}
}
[my_table reloadData];
}
The problem is,I am not able to extract values from the remote object and assign it to the NSManagedObject.I have commented the code which (according to me) should save the values in new object to the managed object. Can someone please help me achieve this?
Thanks

Here is an example of a save I did in a recent project. I have somethings in wrappers so fetching a managed object and saving look a little weird on my end. Really the only major difference I see is the act of saving. Are you saving the new NSManagedObject elsewhere in the code?
dict = (NSDictionary*)data;
#try {
if (dict) {
CaretakerInfo* info = [GenericDataService makeObjectWithEntityName:NSStringFromClass([CaretakerInfo class])];
[info setName:[dict valueForKey:#"name"]];
[info setImageURL:[dict valueForKey:#"photo"]];
[info setCaretakerID:[dict valueForKey:#"id"]];
[GenericDataService save];
}
else {
theError = [Error createErrorMessage:#"No Data" Code:-42];
}
}
#catch (NSException *exception) {
//return an error if an exception
theError = [Error createErrorMessage:#"Exception Thrown While Parsing" Code:-42];
}
If not it should looks something like this...
NSError *error = nil;
[context save:&error];
If you have anymore information about what's happening when you extract or assigning data that would be helpful (error/warning/log messages).

Related

Core Data update does not save and does not give any error, why?

I am using a very simple piece of code to update an NSManagedObject, but the save does not make it to the persistent store (SQLite). There are no error messages and the logs look ok so I am a little lost.
I have scaled down the code as much as possible to try and isolate the problem as shown below.
The logs tell me that the orderNumber and status are set correctly and also the debug output of the arrays are all correct, but my simple update still fails without any error at all.
+ (int) synchOrderWithStatusUpdate:(NSString *)orderNumber : (int)status {
if ([NWTillHelper isDebug] == 1) {
NSNumber *statusCheck = [NSNumber numberWithInt:status];
NSLog(#"WebServices:synchOrderWithStatusUpdate:ordernumber = %#, status = %d, status2 = %#", orderNumber, status, statusCheck);
}
synchOrderErrorCode = 0;
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = appDelegate.persistentContainer.viewContext;
// *** The query for all tables uses orderNumber as selection so we set that up first for re use
NSPredicate *predicateOrderNumber =[NSPredicate predicateWithFormat:#"orderNumber like[cd] %#", [NWTillHelper getCurrentOrderNumber]];
NSFetchRequest *fetchRequestOh = [[NSFetchRequest alloc] initWithEntityName:#"OrderHead"];
NSFetchRequest *fetchRequestOrp = [[NSFetchRequest alloc] initWithEntityName:#"OrderRow"];
NSFetchRequest *fetchRequestTender = [[NSFetchRequest alloc] initWithEntityName:#"Tender"];
fetchRequestOh.predicate = predicateOrderNumber;
fetchRequestOrp.predicate = predicateOrderNumber;
fetchRequestTender.predicate = predicateOrderNumber;
fetchRequestOh.resultType = NSDictionaryResultType;
fetchRequestOrp.resultType = NSDictionaryResultType;
fetchRequestTender.resultType = NSDictionaryResultType;
NSError *errorOh = nil;
NSMutableArray *orderHeads = [[context executeFetchRequest:fetchRequestOh error:&errorOh] mutableCopy];
NSError *errorOrp = nil;
NSArray *orderRows = [[context executeFetchRequest:fetchRequestOrp error:&errorOrp] mutableCopy];
NSError *errorTender = nil;
NSArray *tenderRows = [[context executeFetchRequest:fetchRequestTender error:&errorTender] mutableCopy];
if ([NWTillHelper isDebug] == 1) {
NSLog(#"WebServices:synchOrderWithStatusUpdate:orderHeadsArray: %#", [orderHeads objectAtIndex:0]);
NSLog(#"WebServices:synchOrderWithStatusUpdate:orderRowsArray: %#", orderRows);
NSLog(#"WebServices:synchOrderWithStatusUpdate:tenderRowsArray: %#", tenderRows);
}
// *** Set the status before upload since this dictates what will happen in backend
// *** regardless if synch is successful or not
NSManagedObject *orderHeadObject = nil;
orderHeadObject = [orderHeads objectAtIndex:0];
[orderHeadObject setValue:[NSNumber numberWithInt:status] forKey:#"status"];
// Save the objects to persistent store
NSError *error = Nil;
[context save:&error];
NSLog(#"Jongel Error = %#", error);
if(error !=nil) {
if([NWTillHelper isDebug] == 1) {
NSLog(#"Can't Save! %# %#", error, [error localizedDescription]);
}
synchOrderErrorCode = 99;
}
return 10101;
The orderHeads are fetched as dictionaries. The NSManagedObjectContext will not be aware of any changes made to a dictionary. Only NSManagedObjects will be managed by the NSManagedObjectContext, hence the name ;-)
Try to fetch the orderHeadObject as an NSManagedObject as this will allow you to save the changes back into the store. If you need the dictionary for JSON serialisation: Just fetch it again as a dictionary after you have made the changes. That second fetch will be very fast since all values of the object are already cached, so CoreData won't have to reload from the database.

Threads Using Managed Objects Between Contexts

I am at that point where I am losing hair on this so I figured I'd reach out to the great minds here who have had experience using Objective C with Threads and core data. I am having issues with managed objects inserted in on thread in a NSPrivateQueue Context being accessed from the main thread. So at a high level I am using AFNetworking to generate a thread to make requests to retrieve JSON data from a server and then insert the values into my persistent store core data. After this is done I have another thread for downloading some binary data using AFNetworking as well. I have set up 2 managed contexts for this as shown below:
(NSManagedObjectContext *)masterManagedContext {
if (_masterManagedContext != nil) {
return _masterManagedContext;
}
NSPersistentStoreCoordinator *coord = [self coordinator];
if (coord != nil) {
_masterManagedContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
_masterManagedContext.stalenessInterval = 0.0;
[_masterManagedContext performBlockAndWait:^{
[_masterManagedContext setPersistentStoreCoordinator:coord];
}];
}
return _masterManagedContext;
}
// Return the NSManagedObjectContext to be used in the background during sync
- (NSManagedObjectContext *)backgroundManagedContext {
if (_backgroundManagedContext != nil) {
return _backgroundManagedContext;
}
NSManagedObjectContext *masterContext = [self masterManagedContext];
if (masterContext != nil) {
_backgroundManagedContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
_backgroundManagedContext.stalenessInterval = 0.0;
[_backgroundManagedContext performBlockAndWait:^{
[_backgroundManagedContext setParentContext:masterContext];
}];
}
return _backgroundManagedContext;
}
As is shown above I am using a child context and the parent context. When I make I call to fetch the json data I have something like below:
AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
//Initially delete all records in table. This will change
[[Singleton sharedInstance]removeEntityObjects:className];
for (int x=0; x < [JSON count]; x++) {
NSMutableDictionary *curDict = [JSON objectAtIndex:x];
[[CoreDatam sharedinstance] insertEmployeesWithDictionary:curDict];
}else {
/* do nothing */
}
}
}
} failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error,id JSON) {
[delegate performSelector:#selector(didNotCompleteSync:) withObject:className];
}];
[operations addObject:operation];
}
[self.AFClient enqueueBatchOfHTTPRequestOperations:operations progressBlock:^(NSUInteger numberOfCompletedOperations, NSUInteger totalNumberOfOperations) {
NSLog(#"Currenlty downloaded table data %d of %d!",numberOfCompletedOperations,totalNumberOfOperations);
} completionBlock:^(NSArray *operations) {
if (_syncInProgress) {
[[CoreDatam sharedInstance]updateEmpForId];
[self downloadAllFiles];
}
}];
}`
for the insert function I have something like below:
insertEmployeesWithDictionary:curDict {
[[self backgroundManagedContext]performBlockAndWait:^{
Employee *emp = [NSEntityDescription insertNewObjectForEntityForName:#"Employee"
inManagedObjectContext:[self backgroundManagedContext]];
/* Issues saving null into core data based on type.*/
[emp setFirst:[dictCopy objectForKey:#"first"]];
[emp setLast:[dictCopy objectForKey:#"last"]];
NSError *error = nil;
BOOL saved;
saved = [[self backgroundManagedContext] save:&error];
if (!saved) {
NSLog(#"Whoops, couldn't save: %#", [error localizedDescription]);
}
[self saveMasterContext];
}];
}
The issue is below where I am trying to access the managed objects in the method that is in the completion block above:
updateEmpId {
[self.backgroundManagedContext performBlockAndWait:^{
NSError *error = nil;
NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:#"Employee"];
[request setSortDescriptors:[NSArray arrayWithObject:
[NSSortDescriptor sortDescriptorWithKey:#"last" ascending:YES]]];
myEmps = [self.backgroundManagedContext executeFetchRequest:request error:nil];
for (Employee *moEmp in myEmps) {
[[self backgroundManagedContext]refreshObject:moEmp mergeChanges:YES];
moEmp.photo = #'default.pic';
}
NSError *saveError = nil;
if (![self.backgroundManagedContext save:&saveError]) {
NSLog(#"Whoops, couldn't save: %#", [error localizedDescription]);
}
[self saveMasterContext];
}
The issue is that I am getting very inconsistent behavior when looking at the managed objects that are modified in the main thread. Is it still necessary to pass managed objectIds when using a parent child context relation? if so how can I do so for the above example? Any help greatly appreciated.
You should pass NSManagedObjectIDs or re-fetch in the main thread context, yeah. If you pass object IDs, get the IDs from the background context after saving the new Employee objects, and use existingObjectWithID:error: in the parent context to instantiate them there. Or just re-do the fetch request from your updateEmpId code block in the masterManagedContext.

NSDictionary won't fill up

I have the following piece of code.
-(NSDictionary *)getPlayers
{
NSManagedObjectContext *context = self.genkDatabase.managedObjectContext;
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Team"
inManagedObjectContext:context];
fetchRequest.predicate = [NSPredicate predicateWithFormat:#"position ==[c] %#", #"Doelman"];
[fetchRequest setEntity:entity];
NSError *error;
NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:&error];
if (fetchedObjects == nil) {
// Handle the error.
}else
for (Team *info in fetchedObjects) {
[_photos setObject:info.image forKey:#"player_imgUrl"];
[_photos setObject:info.name forKey:#"player_name"];
}
NSLog(#"%#",_photos);
return _photos;
But for some reason or another my NSLog always gives (null) back. But when I do this
[_photos setObject:info.image forKey:#"player_imgUrl"];
[_photos setObject:info.name forKey:#"player_name"];
NSLog(#"name: %#",info.name );
NSLog(#"url: %#",info.image );
It gives the right data back.
Can somebody help?
Kind regards.
Make sure you have instantiated your _photos dictionary somewhere with the following line of code:
_photos = [[NSMutableDictionary alloc] init];
Just defining it as an instance variable or a property is not enough.
You have a mistake which may not be directly connected to the issue. In for loop you always reset name and image for the same key. so at the end of the loop your dictionary must have one name and one image, not all the ones from the array. You should change it
UPDATE:probably something like this:
int count = fetchedObjects.count;
for (int i = 0; i < count; i++)
{
NSString *image_key = [NSString stringWithFormat:#"player_imgUrl%d",i];
NSString *name_key = [NSString stringWithFormat:#"player_name%d",i];
[_photos setObject:[[fetchedObjects objectAtIndex:i] image] forKey:image_key];
[_photos setObject:[[fetchedObjects objectAtIndex:i] name] forKey:name_key];
}

save records from WCF service in CoreData

I am new to iOS development and CoreData too. I am calling a .Net WCF service for displaying data in a UITableViewcontroller in my app.I am saving this data in CoreData. When I add a new record on the server,I want it to get displayed in the UITableViewController as well as saved in CoreData.But this doesnt happen.I have to do a "Reset Contents and Settings" on the Simulator and then run the application again. When I do this,the app displays the latest records from the service.It also saves the new record in CoreData.I am using SUDZC for interacting with the wcf service.The code for calling the service,displaying data in UITableViewController and saving it to CoreData looks like this:
- (void)viewDidLoad
{
[super viewDidLoad];
self.detailViewController = (DetailViewController *)[[self.splitViewController.viewControllers lastObject] topViewController];
[my_table setDataSource:self];
[my_table setDelegate:self];
EDViPadDocSyncService *service = [[EDViPadDocSyncService alloc]init];
[service getAllCategories:self action:#selector(handleGetAllCategories:)];
}
-(void)handleGetAllCategories:(id)value
{
if([value isKindOfClass:[NSError class]])
{
NSLog(#"This is an error %#",value);
return;
}
if([value isKindOfClass:[SoapFault class]])
{
NSLog(#"this is a soap fault %#",value);
return;
}
NSMutableArray *result = (NSMutableArray*)value;
self.myData = [[NSMutableArray array] init];//array for storing 'category name'
self.catId = [[NSMutableArray array]init];//array for storing 'category ID'
self.myData=[self getCategories];
/*store data in Core Data - START*/
NSMutableArray *coreDataCategoryarray = [[NSMutableArray alloc]init];
NSManagedObjectContext *context = [self managedObjectContext];
Categories *newCategory;//this is the CoreData 'Category' object
for(int j=0;j<[result count];j++)
{
EDVCategory *edvCat = [[EDVCategory alloc]init];//this is the SUDZC 'Category' object
edvCat = [result objectAtIndex:j];
if ([self.catId count]>0) {
for (int i=0; i<[self.catId count]; i++) {
if ([edvCat categoryId] == [[self.catId objectAtIndex:i] integerValue]) {
checkFlag=TRUE;
}
}
}
if (checkFlag == FALSE) {
newCategory = [NSEntityDescription insertNewObjectForEntityForName:#"Categories" inManagedObjectContext:context];
[newCategory setCategoryId:[NSNumber numberWithInt:[edvCat categoryId]]];
[newCategory setCategoryName:edvCat.categoryName];
[newCategory setDocCount:[NSNumber numberWithInt:[edvCat docCount]]];
[newCategory setCategoryType:[NSNumber numberWithShort:[edvCat categoryType]]];
[newCategory setSubCategoryId:[NSNumber numberWithInt:[edvCat subCategoryId]]];
[coreDataCategoryarray addObject:newCategory];
}
}
/*store data in Core Data - END*/
NSError *error = nil;
if (![context save:&error])
{
[coreDataCategoryarray release];
}
else
{
//return [coreDataCategoryarray autorelease];
[coreDataCategoryarray autorelease];
}
self.myData=[self getCategories];
[my_table reloadData];
}
-(NSMutableArray *)getCategories
{
NSFetchRequest *request = [[[NSFetchRequest alloc] init]autorelease];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Categories" inManagedObjectContext:__managedObjectContext];
NSSortDescriptor *sortByName = [[[NSSortDescriptor alloc] initWithKey:#"categoryId" ascending:YES] autorelease];
[request setSortDescriptors:[NSArray arrayWithObject:sortByName]];
[request setEntity:entity];
entity = nil;
NSError *error = nil;
NSMutableArray *fetchResults = [[__managedObjectContext executeFetchRequest:request error:&error] mutableCopy];
[request setReturnsObjectsAsFaults:NO];
NSManagedObject *aTabrss;
NSMutableArray *arForGetCategory=[[NSMutableArray alloc]init];
for (aTabrss in fetchResults){
[arForGetCategory addObject:[aTabrss valueForKey:#"categoryName"]];
[self.catId addObject:[aTabrss valueForKey:#"categoryId"]];
}
return (arForGetCategory);
}
What changes should I make in my code so that it reflects the latest data from the service and saves it to CoreData(sqlite) at the same time?
It seems like the class that you really need is NSUserDefaults:
http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/nsuserdefaults_Class/Reference/Reference.html

NSManagedObject fail to save it's attributes, but able to save when adding related objects

I'm developing an iOS app using Core Data. And I have a Log entity with one-to-many relationships with Audio, Photo entities, and one-to-one relationship with Status entity. The log also has text, longitude, latitude properties. I can create the log, change its properties, add status entity, these changes would display right, until I quit the App. All the changes would disappear, and I was looking at the sqlite database, all these changes were never persisted in the database. In the database, the status object will just be created, but not linked to the log object.
But if I add an audio or photo object into the log.audioSet or log.photoSet, the changes I made to log, including the changes to text or status, will suddenly be saved into the database.
So it seems the changes are only maintained in the NSManagedObjectContext, until a related one_to_many entity is added and the [[LTLogStore sharedStore] saveChanges] will suddenly start to work.
I am using a singleton to manage the NSManagedObjectContext. Any ideas?
I would post some code if it's relevant. Thanks.
UPDATE: I'm not sure these code is enough. But basically everything works, and displays, it just doesn't save to the database. I'm using the mogenerator to set the text and latitude, but since everything is in the context. I am not sure this is the code you might need.
CODE:
#interface LTLogStore : NSObject{
}
+ (LTLogStore *)sharedStore;
- (void)removeItem:(Log *)p;
- (Log *)createItem;
- (BOOL)saveChanges;
#property(nonatomic, strong) NSFetchedResultsController *resultsController;
#property(nonatomic, strong) NSManagedObjectModel *model;
#property(nonatomic, strong) NSManagedObjectContext *context;
#end
#implementation LTLogStore
#synthesize resultsController;
#synthesize context, model;
+ (LTLogStore *)sharedStore
{
static LTLogStore *sharedStore = nil;
if(!sharedStore){
sharedStore = [[super allocWithZone:nil] init];
}
return sharedStore;
}
+ (id)allocWithZone:(NSZone *)zone
{
return [self sharedStore];
}
- (id)init
{
self = [super init];
if(self) {
model = [NSManagedObjectModel mergedModelFromBundles:nil];
NSPersistentStoreCoordinator *psc =
[[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:model];
// Where does the SQLite file go?
NSString *path = [self itemArchivePath];
NSURL *storeURL = [NSURL fileURLWithPath:path];
NSError *error = nil;
if (![psc addPersistentStoreWithType:NSSQLiteStoreType
configuration:nil
URL:storeURL
options:nil
error:&error]) {
[NSException raise:#"Open failed"
format:#"Reason: %#", [error localizedDescription]];
}
// Create the managed object context
context = [[NSManagedObjectContext alloc] init];
[context setPersistentStoreCoordinator:psc];
// The managed object context can manage undo, but we don't need it
[context setUndoManager:nil];
}
return self;
}
- (NSFetchedResultsController *)resultsController {
if (resultsController !=nil) {
return resultsController;
}
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *e = [[model entitiesByName] objectForKey:#"Log"];
[request setEntity:e];
NSSortDescriptor *sd = [NSSortDescriptor
sortDescriptorWithKey:#"created_at"
ascending:NO];
[request setSortDescriptors:[NSArray arrayWithObject:sd]];
[request setReturnsObjectsAsFaults:NO];
NSFetchedResultsController *fetchedResultsController = [[NSFetchedResultsController alloc]
initWithFetchRequest:request
managedObjectContext:context
sectionNameKeyPath:nil cacheName:#"Root"];
NSError *error;
BOOL success = [fetchedResultsController performFetch:&error];
if (!success) {
//handle the error
}
return fetchedResultsController;
}
- (NSString *)itemArchivePath
{
NSArray *documentDirectories =
NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
// Get one and only document directory from that list
NSString *documentDirectory = [documentDirectories objectAtIndex:0];
NSString *storePath = [documentDirectory stringByAppendingPathComponent:#"store.data"];
return storePath;
}
- (BOOL)saveChanges
{
NSError *err = nil;
BOOL successful = [context save:&err];
NSLog(#"Saving changes to the database");
if (!successful) {
NSLog(#"Error saving: %#", [err localizedDescription]);
}
return successful;
}
- (void)removeItem:(Log *)l
{
[context deleteObject:l];
[self saveChanges];
}
- (Log *)createItem
{
Log *p = [NSEntityDescription insertNewObjectForEntityForName:#"Log"
inManagedObjectContext:context];
[self saveChanges];
return p;
}
#end
#interface Log : _Log {
}
//these two are some custom convenience methods for location attributes, but it does the work of setting the longitude and latitude value in the log object, but calling the [[LTLogStore sharedStore] saveChanges] still won't save it into the database.
-(CLLocation*)location;
-(void)setLocation:(CLLocation*)location;
//this all works
-(Audio*)newAudio;
-(Audio*)newAudioWithPath:(NSString*)audioPath;
//after calling this method, even the log.text changes will be saved to the database.
-(void)addAudioWithPath:(NSString*)audioPath;
-(void)removeAudio:(Audio*)audio;
#end
#import "Log.h"
#import "Audio.h"
#import "LTLogStore.h"
#implementation Log
-(CLLocation*)location{
if (!self.longitude || !self.latitude) {
return nil;
}
CLLocation *l = [[CLLocation alloc] initWithLatitude:[self.latitude doubleValue] longitude:[self.longitude doubleValue]];
return l;
}
-(void)setLocation:(CLLocation*)location{
if (location==nil) {
self.latitude = nil;
self.longitude = nil;
}
self.latitude = [NSNumber numberWithDouble: location.coordinate.latitude];
self.longitude = [NSNumber numberWithDouble:location.coordinate.longitude];
[[LTLogStore sharedStore] saveChanges];
}
-(Audio*)newAudio{
Audio *a = [Audio new];
a.log = self;
return a;
}
-(Audio*)newAudioWithPath:(NSString*)audioPath{
Audio *new = [self newAudio];
[new setKey:audioPath];
return new;
}
-(void)addAudioWithPath:(NSString*)audioPath{
Audio *new = [self newAudio];
[new setKey:audioPath];
[[LTLogStore sharedStore] saveChanges];
}
-(void)removeAudio:(Audio*)audio{
[self.audiosSet removeObject:audio];
[[[LTLogStore sharedStore] context] deleteObject:audio];
[[LTLogStore sharedStore] saveChanges];
}
#end
UPDATE:
Problem solved, see answer.
UPDATE QUESTION: Why is my overriding causing the problem? Can someone explain the cause behind the magic of Core Data or maybe KVO behind scene?
Problem solved, I overrode the willChangeValueForKey method in the Log class, which caused the problem, I thought the code is irrelevant. But it IS:
- (void)willChangeValueForKey:(NSString *)key{
//I added the following line to fix my problem
[super willChangeValueForKey:key];
//this is the original line, I want to have this
//because I want to have a isBlank property
//so I can see if the user modified the log
_isBlank = false;
//I tried to also add the following line to be safe.
//turns out this line is not needed, and it will make the problem occur again
//[super didChangeValueForKey:key];
}