I'm trying to fetch EKEvents from the Event Store to populate a UITableView and display a month list view.
Basically it works and I'm doing it like this:
- (void) reloadEvents
{
for ( NSString *entry in self.calendarA )
{
NSMutableArray *tempArray = [[[NSMutableArray alloc] init] autorelease];
[tempArray addObjectsFromArray:[appDelegate.eventStore eventsMatchingPredicate:[appDelegate.eventStore predicateForEventsWithStartDate:[NSDate fromString:entry] endDate:[[NSDate fromString:entry] midnight] calendars:nil]]];
[tempArray addObjectsFromArray:[self initializeItems:[NSDate fromString:entry] withEndDate:[[NSDate fromString:entry] midnight]]];
[tempArray sortUsingDescriptors:[NSArray arrayWithObject:[[[NSSortDescriptor alloc] initWithKey:#"startDate" ascending:YES] autorelease]]];
[[self.calendarD objectForKey:entry] addObjectsFromArray:tempArray];
}
dispatch_async(dispatch_get_main_queue(), ^(void)
{
[self redrawTableCells];
});
}
reloadEvents is called from within a
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void)
{
[self reloadEvents];
});
as fetching events happens synchronously and it locks the UI for that time, I'm using GCD. The NSDate parts are my own categories on NSDate.
Now, when my view controller loads, events are fetched from the Event Store and displayed correctly. The view controller also listens for EKEventStoreChangedNotification and that's where my app crashes. When I change an event outside my app it receives a notification and tries to reload the event data, but then...
*** -[CFString length]: message sent to deallocated instance 0x666f530
EDIT
I've changed reloadEvents to the following:
- (void) reloadEvents
{
NSArray *daysArray = [[self.calendarD allKeys] sortedArrayUsingSelector:#selector(compare:)];
for ( NSString *entry in daysArray )
{
NSMutableArray *tempArray = [[NSMutableArray alloc] init];
[tempArray addObjectsFromArray:[appDelegate.eventStore eventsMatchingPredicate:[appDelegate.eventStore predicateForEventsWithStartDate:[NSDate fromString:entry] endDate:[[NSDate fromString:entry] midnight] calendars:nil]]];
[tempArray addObjectsFromArray:[self initializeItems:[NSDate fromString:entry] withEndDate:[[NSDate fromString:entry] midnight]]];
[tempArray sortUsingDescriptors:[NSArray arrayWithObject:[[[NSSortDescriptor alloc] initWithKey:#"startDate" ascending:YES] autorelease]]];
[[self.calendarD objectForKey:entry] addObjectsFromArray:tempArray];
[tempArray release];
}
dispatch_async(dispatch_get_main_queue(), ^(void)
{
[self redrawTableCells];
});
}
and with this, the app doesn't crash anymore.
Seems like something changed calendarA and therefore the entry was already deallocated (which, after having found the cause of the problem, is absolutely logical).
Related
I have array of NSObjects. Each element have the following properties (name, id, comment). I'm using parse.com server to send and retrieve my iOS app data.
My code for saving data is the following
- (IBAction)order:(id)sender {
PFObject *obj = [PFObject objectWithClassName:#"Table_1"];
for (SelectedIteam *iteam in _dataArray) {
[obj setObject:iteam.name forKey:#"Name"];
[obj setObject:iteam.id forKey:#"ID"];
[obj setObject:iteam.comment forKey:#"Comment"];
[obj saveInBackground];
}
}
But only the last element of my nsarray is saved in parse server.
How can i save all elements from array to parse server.
I would use PFObject's saveAllInBackground method instead. Otherwise you are making one api call to Parse for every object in the array when you can achieve the same with just one call.
- (IBAction)order:(id)sender {
NSMutableArray *items = [[NSMutableArray alloc] init];
for (SelectedIteam *iteam in _dataArray) {
PFObject *obj = [[PFObject objectWithClassName:#"Table_1"];
[obj setObject:iteam.name forKey:#"Name"];
[obj setObject:iteam.id forKey:#"ID"];
[obj setObject:iteam.comment forKey:#"Comment"];
[items addObject: obj];
}
[PFObject saveAllInBackground:items];
}
https://parse.com/docs/ios/api/Classes/PFObject.html#//api/name/saveAllInBackground:
To add all elements the PFObject must be defined in for loop. So the correct code will be`
- (IBAction)order:(id)sender {
for (SelectedIteam *iteam in _dataArray) {
PFObject *obj = [PFObject objectWithClassName:#"Table_1"];
[obj setObject:iteam.name forKey:#"Name"];
[obj setObject:iteam.id forKey:#"ID"];
[obj setObject:iteam.comment forKey:#"Comment"];
[obj saveInBackground];
}
}
I'm totally stumped on this one. I have an NSMutableArray which is declared in my header and set as a property, synthesized etc. I then call a function that allocates and initializes the array, and I add custom objects to it. I do a for each loop after the objects are added to ensure that they are actually contained within the array and they are. Once the program goes outside of this function scope, though, suddenly the array is empty.
header file:
#interface ScheduleViewController : UITableViewController {
NSString *login_id;
NSMutableArray *events;
}
- (id)initWithID:(NSString*)l_id;
- (void)grabURLInBackground; // ASIHTTP example method
#property (nonatomic, retain) NSString *login_id;
#property (nonatomic, retain) NSMutableArray *events;
#end
implementation:
#synthesize events;
- (void)requestFinished:(ASIHTTPRequest *)request
{
// Use when fetching text data
NSString *response = [request responseString];
SBJsonParser *parser = [[SBJsonParser alloc] init];
NSArray *eventDics = [parser objectWithString:response error:nil]; // an array of dictionaries of events
NSDateFormatter *dateForm = [[NSDateFormatter alloc] init];
// Allocate empty event object and initialize the mutable array
Event* event = [[Event alloc] init];
self.events = [[NSMutableArray alloc] initWithCapacity:[eventDics count]];
// loop through the array of dictionaries
for (int i = 0; i < [eventDics count]; i++)
{
NSDictionary *dict = [eventDics objectAtIndex:i];
for(NSString *key in dict) {
// for the sake of readability i wont include the code
// but the event is populated here
}
[self.events addObject:event];
[event release];
}
NSLog(#"Array Count: %i", [self.events count]);
for (Event *e in events) {
NSLog(#"eventid: %i, type: %#, price: %f, name: %#", e.event_id, e.type, e.price, e.name);
}
[parser release];
[dateForm release];
}
So the above code works fine and prints out the variables from the Event objects that are stored in the events mutable array.
What I want to do is use the events array in another function now, and when I try to, the count is 0 and also no objects are stored in the array when I look at it.
In viewDidUnload I set self.events = nil; and in dealloc I do [self.events release]
You are doing your alloc/init for the Event *event object outside of your for loop. This means you are adding the same object every time you add it to the array. You should move this line:
Event* event = [[Event alloc] init];
To the inside of your
for (int i=0 ... loop.
Not sure that would explain the symptoms you are seeing, but it could, since the following statement:
[event release]
is also releasing that one allocated object once for every time through the loop - so you are releasing the object multiple times. If you move the Event alloc to the inside of the loop then the release will be ok. (adding the object to the array will retain it so its ok to release it, but you need to allocate a new Event each time through the loop).
Basically your code should look like this: (note I've also added an autorelease to your array alloc).
// Allocate empty event object and initialize the mutable array
self.events = [[[NSMutableArray alloc] initWithCapacity:[eventDics count]] autorelease]; // assigning to the retain property will retain it, so autorelease it or it will be retained twice. Could also have used the arrayWithCapacity convenience method here instead and then wouldn't need to autorelease.
// loop through the array of dictionaries
for (int i = 0; i < [eventDics count]; i++)
{
Event* event = [[Event alloc] init]; // Allocate a new Event each time through the loop so you are adding a unique object to the array each time.
NSDictionary *dict = [eventDics objectAtIndex:i];
for(NSString *key in dict) {
// for the sake of readability i wont include the code
// but the event is populated here
}
[self.events addObject:event];
[event release];
}
I see many problems with this code. These include the fact that you are releasing objects at inappropriate times, and that you are getting confused about the scope of different objects. It seems to me that one of the biggest problems that you are having is re-allocating your events array every time the requestFinished: method is called. In your init method, you should do something like this:
- (id)init {
if ((self = [super init])) {
// Since it is a retain property, we should autorelease it when
// assigning to it, thus preventing an extra retain.
self.events = [[[NSMutableArray alloc] initWithCapacity:[eventDics count]] autorelease];
}
}
With that being said, here is how I would rewrite your requestFinished: method, as well as your dealloc method:
- (void)requestFinished:(ASIHTTPRequest *)request {
NSString *response = [request responseString];
SBJsonParser *parser = [[SBJsonParser alloc] init];
NSArray *eventDics = [parser objectWithString:response error:nil]; // an array of dictionaries of events
NSDateFormatter *dateForm = [[NSDateFormatter alloc] init];
// Clear the already allocated events array
[self.events removeAllObjects];
for (int i = 0; i < [eventDics count]; i++) {
// note how I assign event in here
Event *event = [[Event alloc] init];
NSDictionary *dict = [eventDics objectAtIndex:i];
for (NSString *key in dict) {
// Do whatever it is you do here
}
[self.events addObject:event];
[event release];
}
NSLog(#"Array Count: %i", [self.events count]);
for (Event *e in events) {
NSLog(#"eventid: %i, type: %#, price: %f, name: %#", e.event_id, e.type, e.price, e.name);
}
[parser release];
[dateForm release];
}
Finally, you can simply set the events property to nil in the dealloc method:
- (void)dealloc {
self.events = nil;
[super dealloc];
}
The only reason that I can think of for the array being empty is that a) it's contents are being deallocated, or b) it itself is being deallocated and set to nil. The pieces of your code that I fixed could possibly cause both of these. Try the changes that I have made, and see if they make a difference.
So I figured out the problem and it's due to an error on my part. After stepping through the function calls more closely, it turns out that the table view delegate method
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
was being called before populating the array with requestHasFinished. I was calling requestHasFinished indirectly through viewDidLoad but I think that the table view delegate method was being called when the view controller is initialized. Init was being called before viewDidLoad because the view controller is actually handled within a tab view controller which initializes all of the view controllers for each tab at the time when itself is initialized. That's another matter to get into.. I'm not sure if I like everything being initialized and setup before the views are even displayed but.. something to research.
Anyways thanks again for the help.
I am relatively new to Objective-C and now I have a problem in my iPhone app that I don't fully understand.
I try to use a NSMutableDictionary, this does not seem to work as i expect for some reason. When I run the debugger and do po numberToCallerMap to see the dictionary, I get an exception. I have read the documentation for NSMutableDictionary on how to initialize it, but I can not see what I am doing wrong. Help and advice are appreciated. The variable causing me problem is numberToCallerMap, here is the relevant function:
- (void)setData:(NSString*)value{
[list release];
list = [[NSMutableArray alloc] init];
SBJSON *json = [[[SBJSON alloc] init] autorelease];
NSMutableDictionary* numberToCallerMap;
CallerInfo* caller;
NSDictionary* callerInfo;
#try {
NSArray *array = (NSArray*)[json objectWithString:value];
// reading all the items in the array one by one
numberToCallerMap = [NSMutableDictionary dictionary];
for (id *item in array) {
// if the item is NSDictionary (in this case ... different json file will probably have a different class)
NSDictionary *dict2 = (NSDictionary *) item;
CallInfo *data = [CallInfo alloc];
[data initFromDictionary:dict2];
callerInfo = (NSDictionary*)[dict2 valueForKey:#"caller"] ;
//Here, we want the phonenumber to be part of the CallerInfo object instead.
// It is sent from the server as part of the Call-object
NSString* number = (NSString*)[dict2 valueForKey:#"phoneNumber"];
[callerInfo setValue:number forKey:#"phoneNumber"];
caller = (CallerInfo*)[numberToCallerMap valueForKey:number];
if(caller == nil || [caller isKindOfClass:[NSNull class]]){
caller = [CallerInfo alloc];
[caller initFromDictionary:callerInfo];
[numberToCallerMap setValue:caller forKey:number];
[list insertObject:caller atIndex:0];
}
[caller addRecentCall:data];
}
}
#catch (NSException * e) {
[list release];
list = [[NSMutableArray alloc] init];
}
#finally {
[numberToCallerMap release];
}
}
This is probably not the only problem, but you are not alloc-ing your numberToCallerMap dictionary, you are getting it from a convenience class method -- [NSMutableDictionary dictionary] -- that returns it autoreleased. So you should not call release on it yourself.
I have a ViewController defined as follows:
#interface SectionController : UITableViewController {
NSMutableArray *sections;
}
- (void) LoadSections;
When LoadSection is call it makes a call to NSURLConnection to load a url which in turn calls
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
[connection release];
[responseData release];
NSDictionary *results = [responseString JSONValue];
NSMutableArray *jSections = [results objectForKey:#"Items"];
sections = [NSMutableArray array];
for (NSArray* jSection in jSections)
{
Section* section = [Section alloc];
section.Id = [jSection objectForKey:#"Id"];
section.Description = [jSection objectForKey:#"Description"];
section.Image = [jSection objectForKey:#"Image"];
section.Parent = [jSection objectForKey:#"Parent"];
section.ProductCount = [jSection objectForKey:#"ProductCount"];
[sections addObject:section];
[section release];
}
[jSections release];
[results release];
[delegate sectionsLoaded];
[self.view reloadData];
}
The data parses correctly and I now have sections filled with many items.
Calling [self.view reloadData] forces a callback to the delegate method cellForRowAtIndexPath which should then present the data into the cell however its at this point that sections is now nil again.
Can someone please point out my mistake? I must admit I am a newbie to objective c and it probably a pointer issue. What is need to do is retain the value of sections after calling reloadData.
Many thanks.
Seeing the new code the problem is obvious:
sections = [NSMutableArray array];
should become
[sections release];
sections = [[NSMutableArray alloc] init];
note that the array does not become again "nil", is instead deallocated and you get an invalid reference, which might (should) generate a crash on dereferencing.
I suggest you to read some articles on reference counted memory management as it might be not obvious if you are new to Objective-C, and often leads to mistake (i.e: autorelease is not magic at all)
best way to avoid all memory leaks here is just simply use #property (nonatomic, retain) NSMutableArray *sections; by using property you can be sure that all men management works will be correctly managed by system. Just don't forget that property retains value when you doing setSections:, so that you need to pass autoreleased object here.
self.sections = [NSMutableArray array];
...
[self.sections addObject:section];
Also to avoid all problem try to make all objects which should live only in this method autorelease. Like this:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *responseString = [[[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding] autorelease];
NSDictionary *results = [responseString JSONValue];
NSMutableArray *jSections = [results objectForKey:#"Items"];
self.sections = [NSMutableArray array];
for (NSArray* jSection in jSections) {
Section* section = [[[Section alloc] init] autorelease];
section.Id = [jSection objectForKey:#"Id"];
section.Description = [jSection objectForKey:#"Description"];
section.Image = [jSection objectForKey:#"Image"];
section.Parent = [jSection objectForKey:#"Parent"];
section.ProductCount = [jSection objectForKey:#"ProductCount"];
[self.sections addObject:section];
}
[delegate sectionsLoaded];
[self.view reloadData];
}
And also most of object you trying to release already autoreleased:
all params passed into your method shouldn't be released manually, check I think JSONValue also should returns autoreleased object and anything you getting by enumerating or by call objectForKey:
Now this may sound like my earlier problem/question but I've changed and tried a few things that were answered in my other questions to try to make it work, but I've still got the same problem.
I am observing a core data property from within a NSManagedObject sub-class and the method that gets called when the property changes calls another method but in this method it adds Core Data objects which triggers the KVO method which triggers the method again and so forth. Or so it seems, I'm not too sure about that because something different seems to happen, here is the series of events …
I click a button syncing with iCal (this in an IBAction with the exact same code thats in the method syncKVO). This sync works fine.
I add an object to my outline view. All is well.
I change its name which triggers the KVO Declaration (because I changed the 'name' property) which syncs with iCal. Works fine.
I delete the object I just added and somehow it triggers the KVO declaration (thus triggering the method) and puts me into an infinite loop.
Now for some code.
Code inside the NSManagedObject Subclass (called JGManagedObject) …
- (void) awakeFromFetch {
[self addObserver:[NSApp delegate] forKeyPath:#"name" options:0 context:nil];
}
- (void) awakeFromInsert {
[self addObserver:[NSApp delegate] forKeyPath:#"name" options:0 context:nil];
}
+ (void) addObserver{
[self addObserver:[NSApp delegate] forKeyPath:#"name" options:0 context:nil];
}
+ (void) removeObserver{
[self removeObserver:[NSApp delegate] forKeyPath:#"name"];
}
The KVO Declaration (inside the App Delegate) …
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if ([keyPath isEqualToString:#"name"]) {
[self performSelector:#selector(syncKVO:)];
}
}
The Method (also inside the App Delegate)…
- (void)syncKVO:(id)sender {
NSManagedObjectContext *moc = [self managedObjectContext];
[syncButton setTitle:#"Syncing..."];
NSString *dateText = (#"Last Sync : %d", [NSDate date]);
[syncDate setStringValue:dateText];
NSEntityDescription *entityDescription = [NSEntityDescription
entityForName:#"projects" inManagedObjectContext:moc];
NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
[request setEntity:entityDescription];
NSError *error = nil;
NSArray *array = [moc executeFetchRequest:request error:&error];
if (array == nil)
{
NSAlert *anAlert = [NSAlert alertWithError:error];
[anAlert runModal];
}
NSArray *namesArray = [array valueForKey:#"name"];
NSPredicate *predicate = [CalCalendarStore taskPredicateWithCalendars:[[CalCalendarStore defaultCalendarStore] calendars]];
NSArray *tasksNo = [[CalCalendarStore defaultCalendarStore] tasksWithPredicate:predicate];
NSArray *tasks = [tasksNo valueForKey:#"title"];
NSMutableArray *namesNewArray = [NSMutableArray arrayWithArray:namesArray];
[namesNewArray removeObjectsInArray:tasks];
NSLog(#"%d", [namesNewArray count]);
NSInteger *popIndex = [calenderPopup indexOfSelectedItem];
//Load the array
CalCalendarStore *store = [CalCalendarStore defaultCalendarStore];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES);
NSString *supportDirectory = [paths objectAtIndex:0];
NSString *fileName = [supportDirectory stringByAppendingPathComponent:#"oldtasks.plist"];
NSMutableArray *oldTasks = [[NSMutableArray alloc] initWithContentsOfFile:fileName];
[oldTasks removeObjectsInArray:namesArray];
NSLog(#"%d",[oldTasks count]);
//Use the content
NSPredicate* taskPredicate = [CalCalendarStore taskPredicateWithCalendars:[[CalCalendarStore defaultCalendarStore] calendars]];
NSArray* allTasks = [[CalCalendarStore defaultCalendarStore] tasksWithPredicate:taskPredicate];
// Get the calendar
CalCalendar *calendar = [[store calendars] objectAtIndex:popIndex];
// Note: you can change which calendar you're adding to by changing the index or by
// using CalCalendarStore's -calendarWithUID: method
// Loop, adding tasks
for(NSString *title in namesNewArray) {
// Create task
CalTask *task = [CalTask task];
task.title = title;
task.calendar = calendar;
// Save task
if(![[CalCalendarStore defaultCalendarStore] saveTask:task error:&error]) {
NSLog(#"Error");
// Diagnostic error handling
NSAlert *anAlert = [NSAlert alertWithError:error];
[anAlert runModal];
}
}
NSMutableArray *tasksNewArray = [NSMutableArray arrayWithArray:tasks];
[tasksNewArray removeObjectsInArray:namesArray];
NSLog(#"%d", [tasksNewArray count]);
for(NSString *title in tasksNewArray) {
NSManagedObjectContext *moc = [self managedObjectContext];
JGManagedObject *theParent =
[NSEntityDescription insertNewObjectForEntityForName:#"projects"
inManagedObjectContext:moc];
[theParent setValue:nil forKey:#"parent"];
// This is where you add the title from the string array
[theParent setValue:title forKey:#"name"];
[theParent setValue:[NSNumber numberWithInt:0] forKey:#"position"];
}
for(CalTask* task in allTasks)
if([oldTasks containsObject:task.title]) {
[store removeTask:task error:nil];
}
// Create a predicate for an array of names.
NSPredicate *mocPredicate = [NSPredicate predicateWithFormat:#"name IN %#", oldTasks];
[request setPredicate:mocPredicate];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:#"name" ascending:YES];
[request setSortDescriptors:[NSArray arrayWithObject:sortDescriptor]];
// Execute the fetch request put the results into array
NSArray *resultArray = [moc executeFetchRequest:request error:&error];
if (resultArray == nil)
{
// Diagnostic error handling
NSAlert *anAlert = [NSAlert alertWithError:error];
[anAlert runModal];
}
// Enumerate through the array deleting each object.
// WARNING, this will delete everything in the array, so you may want to put more checks in before doing this.
for (JGManagedObject *objectToDelete in resultArray ) {
// Delete the object.
[moc deleteObject:objectToDelete];
}
//Save the array
[namesArray writeToFile:fileName atomically:YES];
[syncButton setTitle:#"Sync Now"];
NSLog(#"Sync Completed");
}
What I've tried …
Filtering the Keypaths that call the KVO Declaration with
if ([keyPath isEqualToString:#"name"]) {
…
}
Detaching and reattaching observers with
[JGManagedObject removeObserver];
//and
[JGManagedObject addObserver];
but with that it works the first time but stops the method the second time saying that it cannot remove the observer because it is not observing, which doesn't make sense because I added the observer again the first time. That is why I left this code out of the actual method else it would stop on the second sync.
I'm not sure whats going on with this, I think I've tried everything. Whats gone wrong?
Any help would be greatly appreciated.
The problem might be here:
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if ([keyPath isEqualToString:#"name"]) {
[self performSelector:#selector(syncKVO:)];
}
}
You call syncKVO: everytime something happens to 'name' regardless of what it is that has actually happened to 'name'. I suggest you start using the object, change and context parameters to determine what has just happened and what action, if any, should be undertaken.
BTW, it's not considered good practice to add a lot of stuff to the app delegate. You might want to put all this syncing stuff into a proper controller class and call [NSApp delegate] when you need it.