On [context save:&error] method, i get this error, but not alwasy. It crashes randomly.
There is no error description.
XCode 9.2, ios 10.3.3
What should i do?
Code:
-(void)changeReadStatusOfConversationWithConvID:(int)convID isRead:(BOOL)isRead{
NSManagedObjectContext *context = [[AppDelegate sharedAppDelegate] managedObjectContext];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"conversation_id == %d", convID];
NSArray *conversations = [self getObjectsForMessageWithEntity:ENTITY_CONVERSATION withPredicate:predicate];
ConversationManagedObject *conversationManagedObj = [conversations firstObject];
if(conversationManagedObj){
conversationManagedObj.unread = !isRead;
__block NSError *error = nil;
if (![[NSThread currentThread] isMainThread]) {
dispatch_async(dispatch_get_main_queue(), ^{
if(![context save:&error]){
NSLog(#"Cant Update Conversation! %# %#", error, [error localizedDescription]);
}else{
NSLog(#"Conversation Updated!!!");
}
});
}else{
if(![context save:&error]){
NSLog(#"Cant Update Conversation! %# %#", error, [error localizedDescription]);
}else{
NSLog(#"Conversation Updated!!!");
}
}
}
}
enter image description here
Related
I'm using RestKit and RRNCollapsableTable. The problem is, when I load view for the first time, RestKit is downloading data from JSON. That delay causes menu to not load. What I'm trying to do is to make CollapsableTable wait for data.
[self requestData:^(BOOL success) {
if (success) {
_menu = [self buildMenu];
[self model];
}
}];
- (void)requestData:(void (^)(BOOL success))completionBlock {
NSFetchRequest *fetchRequest = [NSFetchRequest fetchRequestWithEntityName:#"Messages"];
NSSortDescriptor *byId = [NSSortDescriptor sortDescriptorWithKey:#"customNewsId" ascending:YES];
fetchRequest.sortDescriptors = #[byId];
NSError *error = nil;
// Setup fetched results
self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:[RKManagedObjectStore defaultStore].mainQueueManagedObjectContext
sectionNameKeyPath:#"customNewsId"
cacheName:nil];
//[self.fetchedResultsController setDelegate:self];
BOOL fetchSuccessful = [self.fetchedResultsController performFetch:&error];
if (!fetchSuccessful) {
abort();
}
[[RKObjectManager sharedManager] getObjectsAtPath:#"api/json/get/bZmroLaBCG" parameters:nil success:^(RKObjectRequestOperation *operation, RKMappingResult *mappingResult) {
RKLogInfo(#"Load complete: Table should refresh...");
//[[NSUserDefaults standardUserDefaults] setObject:[NSDate date] forKey:#"LastUpdatedAt"];
//[[NSUserDefaults standardUserDefaults] synchronize];
NSError *error = nil;
if ([[RKManagedObjectStore defaultStore].mainQueueManagedObjectContext hasChanges] && ![[RKManagedObjectStore defaultStore].mainQueueManagedObjectContext saveToPersistentStore:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
completionBlock(YES);
} failure:^(RKObjectRequestOperation *operation, NSError *error) {
RKLogError(#"Load failed with error: %#", error);
completionBlock(NO);
}];
completionBlock(YES);
}
Then BuildMenu is just iterating over fetched objects and put them in section.
-(NSArray *)buildMenu {
__block NSMutableArray *collector = [NSMutableArray new];
NSInteger sections = [self.fetchedResultsController.sections count];
for (NSInteger i = 0; i < sections; i++) {
Messages *message = [_fetchedResultsController objectAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:i]];
MenuSection *section = [MenuSection new];
section.items = #[message.message,message.pushNotificationMessage];
section.title = message.title;
NSLog(#"section.title - %#",section.title);
[collector addObject:section];
}
return [collector copy];
}
Method model is responsible for DataSource for CollapsableTable.
-(NSArray *)model {
return _menu;
}
Thanks in advance for any help.
Greetings.
I have a Core Data data model such as
I want to display the Teams.name associated with each Batting object in my UITableViewCell. When I try to access batting.teams.name it returns NULL.
My opening view controller has a string passed in then creates a new viewController with NSPredicate based from Master.nameLast and lists all names matching
and the NSFetchedResultsController which created the above list
#pragma mark - Fetched Results Controller Section
- (NSFetchedResultsController *)fetchedResultsController {
if(_fetchedResultsController != nil) {
return _fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSManagedObjectContext *context = [self managedObjectContext];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Master" inManagedObjectContext:context];
[fetchRequest setEntity:entity];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"debut" ascending:YES];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"nameLast = [c]%#", lastName];
[fetchRequest setPredicate:predicate];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
fetchRequest.sortDescriptors = sortDescriptors;
_fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:context sectionNameKeyPath:nil cacheName:nil];
return _fetchedResultsController;
}
My next view controller then lists all Batting properties associated with the selected Master NSManagedObject.
But when I try to access batting.teams.name it returns NULL!!!!! If I NSLog the entity from my delegate they are set but I can't access Teams.name from it's Batting.teams relationship
#pragma mark - Fetched Results Controller Section
- (NSFetchedResultsController *)fetchedResultsController {
if(_fetchedResultsController != nil) {
return _fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSManagedObjectContext *context = [self managedObjectContext];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Batting" inManagedObjectContext:context];
[fetchRequest setEntity:entity];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"yearID" ascending:YES];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"playerID = %# " , selectedMaster.playerID];
[fetchRequest setPredicate:predicate];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
fetchRequest.sortDescriptors = sortDescriptors;
_fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:context sectionNameKeyPath:nil cacheName:nil];
return _fetchedResultsController;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"playerStats" forIndexPath:indexPath];
Batting *batting = [self.fetchedResultsController objectAtIndexPath:indexPath];
NSString *team = batting.teams.name; //NULL NULL NULL
// Configure the cell...
double average = [batting.h doubleValue]/[batting.ab doubleValue];
NSString *averageStr = [[NSString stringWithFormat:#"%.3f", average] substringFromIndex:1];
cell.textLabel.text = [NSString stringWithFormat:#"%# %#", batting.yearID, batting.teams.name];
cell.detailTextLabel.text = [NSString stringWithFormat:#"H: %#, AVG: %#, HR: %#, RBI: %#, SB: %#, R: %#, BB: %#, K: %#",
batting.h, averageStr , batting.hr, batting.rbi, batting.sb, batting.r, batting.bb, batting.so];
cell.detailTextLabel.textColor = [UIColor grayColor];
return cell;
}
returns null for the second argument????????
cell.textLabel.text = [NSString stringWithFormat:#"%# %#", batting.yearID, batting.teams.name];
and this is the Teams entity logged from the AppDelegate
//
// AppDelegate.m
// Baseball Stats
//
// Created by Jason Steindorf on 6/6/15.
// Copyright (c) 2015 Jason Steindorf. All rights reserved.
//
#import "AppDelegate.h"
#import "Master.h"
#import "Teams.h"
#import "Batting.h"
#implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
NSError *error;
NSString* dataPath_MASTER = [[NSBundle mainBundle] pathForResource:#"master" ofType:#"json"];
NSArray* MASTER = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:dataPath_MASTER]
options:kNilOptions
error:&error];
NSString* dataPath_TEAMS = [[NSBundle mainBundle] pathForResource:#"teams" ofType:#"json"];
NSArray* TEAMS = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:dataPath_TEAMS]
options:kNilOptions
error:&error];
NSString* dataPath_ABC = [[NSBundle mainBundle] pathForResource:#"abc" ofType:#"json"];
NSArray* BATTING_ABC = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:dataPath_ABC]
options:kNilOptions
error:&error];
NSString* dataPath_DEFGH = [[NSBundle mainBundle] pathForResource:#"defgh" ofType:#"json"];
NSArray* BATTING_DEFGH = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:dataPath_DEFGH]
options:kNilOptions
error:&error];
NSString* dataPath_IJKLM = [[NSBundle mainBundle] pathForResource:#"ijklm" ofType:#"json"];
NSArray* BATTING_IJKLM = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:dataPath_IJKLM]
options:kNilOptions
error:&error];
NSString* dataPath_NOPQR = [[NSBundle mainBundle] pathForResource:#"nopqr" ofType:#"json"];
NSArray* BATTING_NOPQR = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:dataPath_NOPQR]
options:kNilOptions
error:&error];
NSString* dataPath_ST = [[NSBundle mainBundle] pathForResource:#"st" ofType:#"json"];
NSArray* BATTING_ST = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:dataPath_ST]
options:kNilOptions
error:&error];
NSString* dataPath_UVWXYZ = [[NSBundle mainBundle] pathForResource:#"uvwxyz" ofType:#"json"];
NSArray* BATTING_UVWXYZ = [NSJSONSerialization JSONObjectWithData:[NSData dataWithContentsOfFile:dataPath_UVWXYZ]
options:kNilOptions
error:&error];
// Test listing all Master from the store
NSFetchRequest *fetchRequestMaster = [[NSFetchRequest alloc] init];
NSEntityDescription *entityMaster = [NSEntityDescription entityForName:#"Master" inManagedObjectContext:self.managedObjectContext];
[fetchRequestMaster setEntity:entityMaster];
NSArray *fetchedObjectsMaster = [self.managedObjectContext executeFetchRequest:fetchRequestMaster error:&error];
NSLog(#"Number of records in master.json - %d", (int)[fetchedObjectsMaster count]);
for (id m in MASTER) {
Master *master = [NSEntityDescription insertNewObjectForEntityForName:#"Master"
inManagedObjectContext:self.managedObjectContext];
master.nameFirst = [m objectForKey:#"nameFirst"];
master.nameLast = [m objectForKey:#"nameLast"];
master.debut = [m objectForKey:#"debut"];
master.playerID = [m objectForKey:#"playerID"];
NSError *error;
if (![self.managedObjectContext save:&error]) {
NSLog(#"Whoops, couldn't save: %#", [error localizedDescription]);
}
}
fetchedObjectsMaster = [self.managedObjectContext executeFetchRequest:fetchRequestMaster error:&error];
for (Master *master in fetchedObjectsMaster) {
NSLog(#"first name: %#", master.nameFirst);
NSLog(#"last name: %#", master.nameLast);
NSLog(#"debut: %#", master.debut);
NSLog(#"playerID: %#\n\n", master.playerID);
}
// Test listing all Master from the store
NSFetchRequest *fetchRequestTeams = [[NSFetchRequest alloc] init];
NSEntityDescription *entityTeams = [NSEntityDescription entityForName:#"Teams" inManagedObjectContext:self.managedObjectContext];
[fetchRequestTeams setEntity:entityTeams];
NSArray *fetchedObjectsTeams = [self.managedObjectContext executeFetchRequest:fetchRequestTeams error:&error];
NSLog(#"Number of records in teams.json - %d", (int)[fetchedObjectsTeams count]);
for (id t in TEAMS) {
Teams *team = [NSEntityDescription insertNewObjectForEntityForName:#"Teams"
inManagedObjectContext:self.managedObjectContext];
team.name = [t objectForKey:#"name"];
team.minYearID = [t objectForKey:#"minYearID"];
team.maxYearID = [t objectForKey:#"maxYearID"];
team.teamID = [t objectForKey:#"teamID"];
NSError *error;
if (![self.managedObjectContext save:&error]) {
NSLog(#"Whoops, couldn't save: %#", [error localizedDescription]);
}
}
fetchedObjectsTeams = [self.managedObjectContext executeFetchRequest:fetchRequestTeams error:&error];
for (Teams *team in fetchedObjectsTeams) {
NSLog(#"name: %#", team.name);
NSLog(#"minYearID: %#", team.minYearID);
NSLog(#"maxYearID: %#", team.maxYearID);
NSLog(#"teamID: %#\n\n", team.teamID);
}
NSFetchRequest *fetchRequestBatting = [[NSFetchRequest alloc] init];
NSEntityDescription *entityBatting = [NSEntityDescription entityForName:#"Batting" inManagedObjectContext:self.managedObjectContext];
[fetchRequestBatting setEntity:entityBatting];
NSArray *fetchedObjectsBatting = [self.managedObjectContext executeFetchRequest:fetchRequestBatting error:&error];
NSLog(#"Number of records in battingFiles.json - %d", (int)[fetchedObjectsBatting count]);
for (id b in BATTING_UVWXYZ) {
Batting *batting = [NSEntityDescription insertNewObjectForEntityForName:#"Batting"
inManagedObjectContext:self.managedObjectContext];
batting.playerID = [b objectForKey:#"playerID"];
batting.h = [b objectForKey:#"h"];
batting.ab = [b objectForKey:#"ab"];
batting.hr = [b objectForKey:#"hr"];
batting.rbi = [b objectForKey:#"rbi"];
batting.sb = [b objectForKey:#"sb"];
batting.r = [b objectForKey:#"r"];
batting.bb = [b objectForKey:#"bb"];
batting.so = [b objectForKey:#"so"];
batting.yearID = [b objectForKey:#"yearID"];
batting.teamID = [b objectForKey:#"teamID"];
NSError *error;
if (![self.managedObjectContext save:&error]) {
NSLog(#"Whoops, couldn't save: %#", [error localizedDescription]);
}
}
fetchedObjectsBatting = [self.managedObjectContext executeFetchRequest:fetchRequestBatting error:&error];
for (Batting *b in fetchedObjectsBatting) {
NSLog(#"playerID: %#", b.playerID);
NSLog(#"h: %#", b.h);
NSLog(#"ab: %#", b.ab);
NSLog(#"hr: %#", b.hr);
NSLog(#"rbi: %#", b.rbi);
NSLog(#"sb: %#", b.sb);
NSLog(#"r: %#", b.r);
NSLog(#"bb: %#", b.bb);
NSLog(#"so: %#", b.so);
NSLog(#"yearID: %#", b.yearID);
NSLog(#"teamID: %#\n\n", b.teamID);
}
return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application {
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}
- (void)applicationDidEnterBackground:(UIApplication *)application {
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
- (void)applicationWillEnterForeground:(UIApplication *)application {
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}
- (void)applicationWillTerminate:(UIApplication *)application {
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
// Saves changes in the application's managed object context before the application terminates.
[self saveContext];
}
#pragma mark - Core Data stack
#synthesize managedObjectContext = _managedObjectContext;
#synthesize managedObjectModel = _managedObjectModel;
#synthesize persistentStoreCoordinator = _persistentStoreCoordinator;
- (NSURL *)applicationDocumentsDirectory {
// The directory the application uses to store the Core Data store file. This code uses a directory named "steindorf.Baseball_Stats" in the application's documents directory.
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
- (NSManagedObjectModel *)managedObjectModel {
// The managed object model for the application. It is a fatal error for the application not to be able to find and load its model.
if (_managedObjectModel != nil) {
return _managedObjectModel;
}
NSURL *modelURL = [[NSBundle mainBundle] URLForResource:#"Baseball_Stats" withExtension:#"momd"];
_managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
return _managedObjectModel;
}
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
// The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it.
if (_persistentStoreCoordinator != nil) {
return _persistentStoreCoordinator;
}
// Create the coordinator and store
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:#"Baseball_Stats.sqlite"];
NSLog(#"%#", storeURL);
NSError *error = nil;
NSString *failureReason = #"There was an error creating or loading the application's saved data.";
if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {
// Report any error we got.
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
dict[NSLocalizedDescriptionKey] = #"Failed to initialize the application's saved data";
dict[NSLocalizedFailureReasonErrorKey] = failureReason;
dict[NSUnderlyingErrorKey] = error;
error = [NSError errorWithDomain:#"YOUR_ERROR_DOMAIN" code:9999 userInfo:dict];
// Replace this with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return _persistentStoreCoordinator;
}
- (NSManagedObjectContext *)managedObjectContext {
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.)
if (_managedObjectContext != nil) {
return _managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (!coordinator) {
return nil;
}
_managedObjectContext = [[NSManagedObjectContext alloc] init];
[_managedObjectContext setPersistentStoreCoordinator:coordinator];
return _managedObjectContext;
}
#pragma mark - Core Data Saving support
- (void)saveContext {
NSManagedObjectContext *managedObjectContext = self.managedObjectContext;
if (managedObjectContext != nil) {
NSError *error = nil;
if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
}
}
#end
In the block below, you need to assign the team to batting.
batting.teams = {your_team_object}
Then you will be able to access the team information. You can create another fetch to Core Data using the teamID to retrieve the team object.
for (id b in BATTING_UVWXYZ) {
Batting *batting = [NSEntityDescription insertNewObjectForEntityForName:#"Batting"
inManagedObjectContext:self.managedObjectContext];
batting.playerID = [b objectForKey:#"playerID"];
batting.h = [b objectForKey:#"h"];
batting.ab = [b objectForKey:#"ab"];
batting.hr = [b objectForKey:#"hr"];
batting.rbi = [b objectForKey:#"rbi"];
batting.sb = [b objectForKey:#"sb"];
batting.r = [b objectForKey:#"r"];
batting.bb = [b objectForKey:#"bb"];
batting.so = [b objectForKey:#"so"];
batting.yearID = [b objectForKey:#"yearID"];
batting.teamID = [b objectForKey:#"teamID"];
NSPredicate *teamIDPredicate = [NSPredicate predicateWithFormat:#"teamID == %#", [b objectForKey:#"teamID"]];
[fetchRequestTeams setPredicate:predicate];
NSArray *fetchedSpecificTeam = [self.managedObjectContext executeFetchRequest:fetchRequestTeams error:&error];
batting.teams= [fetchedSpecificTeam objectAtIndex:0];
NSError *error;
if (![self.managedObjectContext save:&error]) {
NSLog(#"Whoops, couldn't save: %#", [error localizedDescription]);
}
}
I have a routine that fetches RSS entries in the background and insert these in my NSManagedObjectContext if not already there.
My problem is that this object doesn't find duplicates or crashes, depending on which NSManagedObjectContext I use... Help me, please.
Here's the simplified .h
#interface AsyncFetchEngine : NSObject <NSXMLParserDelegate,NSFetchedResultsControllerDelegate>
#property (strong, nonatomic) dispatch_queue_t rssParserQueue;
#property (strong, nonatomic) NSMutableArray *uRLsToFetch;
#property (strong, nonatomic) NSManagedObjectContext *managedObjectContext;
#property (strong, nonatomic) NSManagedObjectContext *childManagedObjectContext;
#property (strong, nonatomic) NSFetchedResultsController *fetchedResultsController;
- (Boolean) isAlreadyInTheFetchQueue:(Feed *)feed;
- (void) fetchPosts:(Feed *)feed;
- (void) createPostInFeed:(Feed*)feed withTitle:(NSString *)title withContent:(NSString *)content withURL:(NSString *)url withDate:(NSDate *)date;
Now here's the init method:
Note if I set the _childManagedObjectContext's parent here, the program crashes.
-(AsyncFetchEngine *)init
{
_rssParserQueue = dispatch_queue_create("com.example.MyQueue", NULL);
_uRLsToFetch = [[NSMutableArray alloc] initWithCapacity:32];
_childManagedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[_childManagedObjectContext setPersistentStoreCoordinator:[_managedObjectContext persistentStoreCoordinator]];
NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
[center addObserver:self
selector:#selector(contextDidSave:)
name:NSManagedObjectContextDidSaveNotification
object:_childManagedObjectContext];
return self;
}
- (void)contextDidSave:(NSNotification*)notification
{
void (^mergeChanges) (void) = ^ {
[_managedObjectContext mergeChangesFromContextDidSaveNotification:notification];
};
if ([NSThread isMainThread]) {
mergeChanges();
} else {
dispatch_sync(dispatch_get_main_queue(), mergeChanges);
}
}
Fetch method:
Note: not sure which MOC to use to determine localFeed, _managedObjectContext crashes the app.
- (void) fetchPosts:(Feed *)feed
{
if (!_childManagedObjectContext.parentContext) {
[_childManagedObjectContext setParentContext:self.managedObjectContext];
}
if ([self isAlreadyInTheFetchQueue:feed]) {
NSLog(#"AsyncFetchEngine::fetchPosts> \"%#\" is already in the fetch queue", feed.name);
return;
}
[_uRLsToFetch addObject:feed];
NSURL *url=[NSURL URLWithString:feed.rss];
NSURLRequest *req = [[NSURLRequest alloc] initWithURL:url];
if (![NSURLConnection canHandleRequest:req]) {
return;
}
Feed *localFeed = ((Feed *)[_childManagedObjectContext existingObjectWithID:[feed objectID] error:nil]);
dispatch_async(_rssParserQueue, ^{
NSLog(#"AsyncFetchEngine::fetchPosts> Opening %#", feed.rss);
[RSSParser parseRSSFeedForRequest:req success:^(NSArray *feedItems)
{
for(RSSItem *i in feedItems)
{
[self createPostInFeed:localFeed withTitle:i.title withContent:(i.content?i.content:i.itemDescription) withURL:[i.link absoluteString] withDate:(i.pubDate?i.pubDate:[NSDate date])];
}
NSLog(#"AsyncFetchEngine::fetchPosts> Found %d items", [feedItems count]);
[_uRLsToFetch removeObject:feed];
}
failure:^(NSError *error)
{
NSLog(#"AsyncFetchEngine::fetchPosts> RSSParser lost it: %#", [error localizedDescription]);
}];
});
}
- (Boolean) isAlreadyInTheFetchQueue:(Feed *)feed
{
Feed *f=nil;
for (f in _uRLsToFetch) {
if ([f isEqual:feed]){
return YES;
}
}
return NO;
}
NSFecthedResultsController, do I need it that way?
- (NSFetchedResultsController *)fetchedResultsController
{
if (_fetchedResultsController != nil) {
return _fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
// Note: I originally tried to use the main MOC here, but it also used to crash the app.
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Post" inManagedObjectContext:_childManagedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"date" ascending:NO];
NSArray *sortDescriptors = #[sortDescriptor];
[fetchRequest setSortDescriptors:sortDescriptors];
/* NSPredicate *predicate =[NSPredicate predicateWithFormat:#"feed.rss LIKE '%#'", _detailItem.rss];
[fetchRequest setPredicate:predicate]; */
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
aFetchedResultsController.delegate = self;
_fetchedResultsController = aFetchedResultsController;
return _fetchedResultsController;
}
It usually crashes somewhere in this method, according to the dump stack.
If it doesn't crash, I have my post added to a (null) Category...
- (void)createPostInFeed:(Feed*)feed withTitle:(NSString *)title withContent:(NSString *)content withURL:(NSString *)url withDate:(NSDate *)date
{
[_childManagedObjectContext performBlockAndWait:^{
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&error]) {
NSLog(#"Error in refetch: %#",[error localizedDescription]);
abort();
}
}];
NSLog(#"AsyncFetchEngine.h: Searching similar posts among %d", [[self.fetchedResultsController fetchedObjects] count]);
Boolean found=NO;
NSPredicate *predicate=[NSPredicate predicateWithFormat:#"title == %# AND url == %# AND feed == %#", title, url, feed];
NSArray *similarPosts = [_fetchedResultsController.fetchedObjects filteredArrayUsingPredicate:predicate];
if ([similarPosts count] > 0)
{
NSLog(#"\n\n\n\t\tAsyncFetchEngine::fetchPosts> Skipping %# (%#)", title, url);
} else {
NSLog(#"\n\n\n\t\tAsyncFetchEngine::fetchPosts> Putting new post in %#", feed.name);
NSEntityDescription *postEntityDescription = [NSEntityDescription entityForName:#"Post"
inManagedObjectContext:_childManagedObjectContext];
[_childManagedObjectContext performBlock:^{
Post *initPost = (Post *)[[NSManagedObject alloc]
initWithEntity:postEntityDescription
insertIntoManagedObjectContext:_childManagedObjectContext];
initPost.title = title;
initPost.url = url;
initPost.excerpt = content;
initPost.date = date;
initPost.read = nil;
initPost.feed = feed;
NSError *error;
if (![_childManagedObjectContext save:&error])
{
NSLog(#"[createPost] Error saving context: %#", error);
}
NSLog(#"Created: %# (%#)", title, url);
//[[NSNotificationCenter defaultCenter] postNotificationName:#"NewPostAdded" object:self];
}];
}
}
So, my questions are:
When I have multiple MOCs, do I fetch from the main and write to a child?
How should I respectivelly use these above?
Thanks!
Answering my own question for the sake of eventually helping another newbie.
Check NSOperationQueue with Coredata.
There's a very good example here.
I'm trying to pop an alert that says "No records found" if the user does a search and the predicate returns nil.
I tried this, but the alert never gets called. I just get an empty tableview.
- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar {
if (self.sBar.text != nil){
NSPredicate *template = [NSPredicate predicateWithFormat:#"name contains[cd] $SEARCH OR optionOne contains[cd] $SEARCH OR optionTwo contains[cd] $SEARCH"];
NSDictionary *replace = [NSDictionary dictionaryWithObject:self.sBar.text forKey:#"SEARCH"];
NSPredicate *predicate = [template predicateWithSubstitutionVariables:replace];
[fetchedResultsController.fetchRequest setPredicate:predicate];
}
[[fetchedResultsController fetchedObjects] count];
if (fetchedResultsController.fetchedObjects != nil) {
//do nothing
} else {
//display alert
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:#"No records match."
delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
[alert release];
}
NSError *error = nil;
if (![[self fetchedResultsController] performFetch:&error]) {
// Handle error
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort(); // Fail
}
[self.myTable reloadData];
[sBar resignFirstResponder];
}
A predicate does not have a -count. A predicate is an expression that evaluates to true or false. That's it.
You can ask the NSFetchedResultsController for its -fetchedObjects (which returns an array), and then ask that array for its -count, but you can only do this after you invoke -performFetch:.
Ha ha! Got it...
- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar {
if (self.sBar.text != nil) {
NSPredicate *template = [NSPredicate predicateWithFormat:#"name contains[cd] $SEARCH OR optionOne contains[cd] $SEARCH OR optionTwo contains[cd] $SEARCH"];
NSDictionary *replace = [NSDictionary dictionaryWithObject:self.sBar.text forKey:#"SEARCH"];
NSPredicate *predicate = [template predicateWithSubstitutionVariables:replace];
[fetchedResultsController.fetchRequest setPredicate:predicate];
}
NSError *error = nil;
if (![[self fetchedResultsController] performFetch:&error]) {
// Handle error
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
exit(-1); // Fail
}
if ([[fetchedResultsController fetchedObjects] count] != 0) {
[self.myTable reloadData];
[sBar resignFirstResponder];
}
else {
//display alert
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:#"No records match."
delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
[alert release];
}
}
I'm trying to change the fetchRequest's predicate on my NSFetchedResultsController, but when i try to reload the data from the aqgridview, none cell is displayed.
My code:
[NSFetchedResultsController deleteCacheWithName: nil];
NSPredicate *predicate = [NSPredicate predicateWithFormat: #"colection = %#", newcolection ];
[fetchedResultsController.fetchRequest setPredicate:predicate];
NSError *error = nil;
if (![[self fetchedResultsController] performFetch:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
[comicGridView reloadData];
SOLVED:
OK, solved. I had to change the "setContentSize: (CGSize) newSize" method in AQGridView.m:
From:
if (newSize.height < footerHeight + minimumHeight)
To:
if (newSize.height < minimumHeight)
As minimumHeight already contains footerHeight, before, footerHeight is added in twice.
I've solved: answer in the question.