I have an app that creates individual events and stores them in core data. What I need to do it load one individually and then export it by email. The code below works except it exports every event where I need it to just export the index path selected one. The code does load the appropriate record because the NSLog (#"My record is: %#", currentItem); does display only the settings for that event but when the data is exported to email all events are sent. I need the selected event with the event name to export. Any thoughts?
NSInteger index = exportevent.tag;
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:index inSection:0];
CDBaseItem *rawRecord = [self.fetchedResultsController objectAtIndexPath:indexPath];
CDSurveyItem *surveyItem = [CDSurveyItem castObject:rawRecord];
self.recordEditID = [rawRecord.objectID URIRepresentation];
NSManagedObjectID *objectId = [self.managedObjectContext.persistentStoreCoordinator managedObjectIDForURIRepresentation:self.recordEditID];
TSPItem *currentItem = [self.managedObjectContext objectWithID:objectId];
NSString *eventName = nil;
if (currentItem.eventname) {
eventName = currentItem.eventname;
}
else if (surveyItem.eventname) {
eventName = surveyItem.eventname;
}
[self setSelection:indexPath];
if (self.selection)
{
if (currentItem)
{
NSLog (#"My record is: %#", currentItem);
NSData *export = [CDJSONExporter exportContext:currentItem.managedObjectContext auxiliaryInfo:nil];
MFMailComposeViewController *composeVC1 = [[MFMailComposeViewController alloc] init];
composeVC1 = [[MFMailComposeViewController alloc] init];
composeVC1.mailComposeDelegate = self;
[composeVC1 setSubject:[NSString stringWithFormat:#"Settings From %# Event", eventName]];
[composeVC1 setMessageBody:[NSString stringWithFormat:#"Here is the event settings. Simply press on the attachment and then choose Open in iPIX"] isHTML:NO];
[composeVC1 addAttachmentData:export mimeType:#"application/octet-stream" fileName:[NSString stringWithFormat:#"%#.ipix", eventName]];
[self presentViewController:composeVC1 animated:NO completion:^(void){}];
}
[self setSelection:nil];
}
Your NSLog may be correct, but you're not exporting the thing that you're printing. In this line (which I assume is a reference to this project):
NSData *export = [CDJSONExporter exportContext:currentItem.managedObjectContext auxiliaryInfo:nil];
You're telling CDJSONExporter to export the context, not a single object. You get every object because that is what CDJSONExporter does. It gets everything it can find in the context and gives you a data object. It's not designed to do what you're asking it to do.
If you want to convert a single object to JSON, you could
Roll your own JSON conversion code. Since you know what the object looks like, this would be easy. Or...
Implement Encodable on your model object and then use JSONEncoder to convert to JSON. Or...
Find some other open source project that does what you want, instead of this one which does not.
Related
I'm writing this in Swift. I have an NSTextField I've assigned a class in IB defined by:
class MyTextField : NSTextField, NSDraggingDestination {
I've overridden draggingEntered, draggingUpdated, prepareForDragOperation, performDragOperation in the subclass, but none of these is ever called and the system just puts stuff in the field as it sees fit. I want to handle the drag because, among other things, I don't want the default behavior of pasting a URL into the field if the user drags a file to it. Instead, if he does that, I want to get the display name of the file and use that instead.
What am I missing?
One of the responsibilities of any object implementing the <draggingDestination> protocol is to maintain an array of data-types which informs others what sort of data will trigger the methods you mention in your question. To allow your subclass to deal with drags from Finder or the desktop, I've found you need to register for three pasteboard types.
/* Sorry, not using Swift yet */
// MyNSTextField.m
- (void)awakeFromNib {
[self registerForDraggedTypes:#[NSPasteboardTypeString,
NSURLPboardType,
NSFilenamesPboardType]];
}
At least on OS X 10.9, this is sufficient to fire your draggingEntered method. If all you want on the pasteboard is the filename, rather than the full URL or path, you need to (i) extract the name, (ii) clear the pasteboard and (iii) add just the name back onto the pasteboard:
- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender {
NSDragOperation operation = NSDragOperationNone;
NSPasteboard *pBoard = [sender draggingPasteboard];
NSArray *array = [pBoard readObjectsForClasses:#[[NSURL class], [NSString class]]
options:nil];
if ([array count] > 0) {
NSString *filename;
if ([[array firstObject] isKindOfClass:[NSURL class]]) {
// Possibly a file dragged from Finder
NSURL *url = [array firstObject];
filename = [[url pathComponents] lastObject];
} else if ([[array firstObject] isKindOfClass:[NSString class]]) {
// Possibly a file dragged from the desktop
NSString *path = [array firstObject];
BOOL isPath = [[NSFileManager defaultManager] fileExistsAtPath:path];
if (isPath) {
filename = [path lastPathComponent];
}
}
if (filename) {
[pBoard clearContents];
[pBoard setData:[filename dataUsingEncoding:NSUTF8StringEncoding]
forType:NSPasteboardTypeString];
operation = NSDragOperationGeneric;
}
}
return operation;
}
On occasion the drag into the text field will happen so quickly that the above method is not triggered, in which case you're back to the same problem. One way around this is to implement the following text field delegate method:
// From NSTextFieldDelegate Protocol
- (void)textDidChange:(NSNotification *)notification
In this method you can compare the contents of your text field, with the contents of the pasteboard, if you're field now contains a valid system path and this path matches the contents of the pasteboard, you know you need to adjust the string in the text field. Fortunately, this seems to happen so quickly that it looks just like a normal paste operation.
I have a query that grabs 10 objects, and I am trying to have an action that shows you a window with more information on the object selected, I am just new to Xcode and cannot figure out how to push the information to the new view controller. Here is the code I have that creates the query.
PFQuery *query = [PFQuery queryWithClassName:#"Arcade"];
CLLocation *currentLocation = locationManager.location;
PFGeoPoint *userLocation =
[PFGeoPoint geoPointWithLatitude:currentLocation.coordinate.latitude
longitude:currentLocation.coordinate.longitude];
query.limit = 10;
[query whereKey:kPAWParseLocationKey nearGeoPoint:userLocation withinMiles:kPAWWallPostMaximumSearchDistance];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
// The find succeeded.
NSLog(#"Successfully retrieved %d scores.", objects.count);
// Do something with the found objects
int i = 0;
for (PFObject *object in objects) {
if (i >= [self.EventTitles count]) break;//to make sure we only write up to the max number of UILabels available in EventTitles
[(UILabel *)self.EventTitles[i] setText:[object objectForKey:#"name"]];//I assume the "objectId" property of object is an NSString!
i++;
}
} else {
// Log details of the failure
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
and this is the action to push to the new view controller:
-(IBAction)DetailEvent1:(id)sender{
TableDetailViewController *objDetail = [[TableDetailViewController alloc] initWithNibName:#"TableDetailViewController" bundle:nil];
[self addChildViewController:objDetail];
objDetail.view.frame = CGRectMake(0.0f, 0.0f, 320.0f, self.view.bounds.size.height - 0.0f);
[self.view addSubview:objDetail.view];
}
If someone could help me write the one line of code that needs to be added to the DetailEvent1 action so that the chosen object is pushed I would greatly appreciate it.
TableDetailViewController *objDetail =
[[TableDetailViewController alloc]
initWithNibName:#"TableDetailViewController" bundle:nil];
objDetail.query = self.query
In other words, this is the moment you are creating the next view controller. The two view controllers are now in contact (self and objDetail). So this is the moment to pass data across from the one to the other.
Of course, there is no TableDetailViewController property query. Not yet! But you're going to make one, don't you see - so that you can make this exact move.
Oh, and perhaps there is no query property in self either. But you will need one, because you need a way to hold on to the query that you got in that first method so that it is still available to you in the second method. The way to share data between methods of the same object is very often thru a property.
See also this example from my book:
- (void)showItemsForRow: (NSIndexPath*) indexPath {
// create subtable of tracks and go there
TrackViewController *t =
[[TrackViewController alloc] initWithMediaItemCollection:
(self.albums)[indexPath.row]];
[self.navigationController pushViewController:t animated:YES];
}
In that example, I've gone even further: I've actually given TrackViewController a designated initializer so that I can create it and hand it the data all in one line.
I am making a movie of screen using AVCaptureMovieFIleOutput, but it is showing unexpected behaviour.
Like, if I am sending the cropRect parameter the movie captured is fine, but if I making the movie of whole screen instead of movie file it is showing a folder. How can I get rid of that?
Code is :
// Create a capture session
mSession = [[AVCaptureSession alloc] init];
// If you're on a multi-display system and you want to capture a secondary display,
// you can call CGGetActiveDisplayList() to get the list of all active displays.
// For this example, we just specify the main display.
CGDirectDisplayID displayId = kCGDirectMainDisplay;
// Create a ScreenInput with the display and add it to the session
input = [[AVCaptureScreenInput alloc] initWithDisplayID:displayId];
[input setCropRect:rect];
if (!input) {
mSession = nil;
return;
}
if ([mSession canAddInput:input])
[mSession addInput:input];
// Create a MovieFileOutput and add it to the session
mMovieFileOutput = [[AVCaptureMovieFileOutput alloc] init];
if ([mSession canAddOutput:mMovieFileOutput])
[mSession addOutput:mMovieFileOutput];
// Start running the session
[mSession startRunning];
// Delete any existing movie file first
if ([[NSFileManager defaultManager] fileExistsAtPath:[destPath path]])
{
NSError *err;
if (![[NSFileManager defaultManager] removeItemAtPath:[destPath path] error:&err])
{
NSLog(#"Error deleting existing movie %#",[err localizedDescription]);
}
}
// Start recording to the destination movie file
// The destination path is assumed to end with ".mov", for example, #"/users/master/desktop/capture.mov"
// Set the recording delegate to self
[mMovieFileOutput startRecordingToOutputFileURL:destPath recordingDelegate:self];
Have to use setSessionPreset property.
Default value of sessionPreset is AVCaptureSessionPresetHigh and it does not work with the full screen capture. Will have to provide any other preset for that.
I am writing a dictionary application, and i am trying to import raw data from strings, one string per word. Amongst other things, the raw input strings contain the names of the parts of speech the corresponding word belongs to. In my datamodel I have a separate entity for Words and PartOfSpeech, and i want to create one entity of the type PartOfSpeech for each unique part of speech there may be in the input strings, and establish the relationships from the Words to the relevant pars of speech. The PartOfSpeech entity has just one Atribute, name, and one-to-many relationship to the Word:
My first implementation of getting unique PartOfSpeech entities involved caching them in a mutable array and filtering it each time with a predicate. It worked, but it was slow. I decided to speed it up a bit by caching the PartsOfSpeech in an NSDictionary, and now when i try and save the datastore after the import, i get the error "Cannot save objects with references outside of their own stores.". It looks like the problem is in the dictionary, but how can i solve it?
Here is the code that worked:
(in both sniplets managedObjectContext is an ivar, and processStringsInBackground: method runs on a background thread using performSelectorInBackground:withObject: method)
- (void) processStringsInBackground:(NSFetchRequest *)wordStringsReq {
NSError *err = NULL;
NSFetchRequest *req = [[NSFetchRequest alloc] init];
[req setEntity:[NSEntityDescription entityForName:#"PartOfSpeech" inManagedObjectContext:managedObjectContext]];
err = NULL;
NSMutableArray *selectedPartsOfSpeech = [[managedObjectContext executeFetchRequest:req error:&err] mutableCopy];
NSPredicate *p = [NSPredicate predicateWithFormat:#"name like[c] $name"];
// NSPredicate *formNamePredicate = [NSPredicate predicateWithFormat:<#(NSString *)predicateFormat#>]
...
for (int i = 0; i < count; i++){
...
currentPos = [self uniqueEntityWithName:#"PartOfSpeech" usingMutableArray:selectedPartsOfSpeech predicate:p andDictionary:[NSDictionary dictionaryWithObject:partOfSpeech forKey:#"name"]];
...
}
}
- (NSManagedObject *) uniqueEntityWithName:(NSString *) entityName usingMutableArray:(NSMutableArray *)objects predicate:(NSPredicate *)aPredicate andDictionary:(NSDictionary *) params {
NSPredicate *p = [aPredicate predicateWithSubstitutionVariables:params];
NSArray *filteredArray = [objects filteredArrayUsingPredicate:p];
if ([filteredArray count] > 0) {
return [filteredArray objectAtIndex:0];
}
NSManagedObject *newObject = [NSEntityDescription insertNewObjectForEntityForName:entityName inManagedObjectContext:managedObjectContext];
NSArray *dicKeys = [params allKeys];
for (NSString *key in dicKeys) {
[newObject willChangeValueForKey:key];
[newObject setPrimitiveValue:[params valueForKey:key] forKey:key];
[newObject didChangeValueForKey:key];
}
[objects addObject:newObject];
return newObject;
}
And here is the same, but with caching using NSMutableDictionary, which fails to save afterwards:
- (void) processStringsInBackground:(NSFetchRequest *)wordStringsReq {
NSError *err = NULL;
[req setEntity:[NSEntityDescription entityForName:#"PartOfSpeech" inManagedObjectContext:managedObjectContext]];
NSArray *selectedPartsOfSpeech = [managedObjectContext executeFetchRequest:req error:&err];
NSMutableDictionary *partsOfSpeechChache = [[NSMutableDictionary alloc] init];
for (PartOfSpeech *pos in selectedPartsOfSpeech) {
[partsOfSpeechChache setObject:pos forKey:pos.name];
}
...
for (int i = 0; i < count; i++){
...
currentPos = [self uniqueEntity:#"PartOfSpeech" withName:partOfSpeech usingDictionary:partsOfSpeechChache];
...
}
}
- (NSManagedObject *)uniqueEntity:(NSString *) entityName withName:(NSString *) name usingDictionary:(NSMutableDictionary *) dic {
NSManagedObject *pos = [dic objectForKey:name];
if (pos != nil) {
return pos;
}
NSManagedObject *newPos = [NSEntityDescription insertNewObjectForEntityForName:entityName inManagedObjectContext:managedObjectContext];
[newPos willChangeValueForKey:#"name"];
[newPos setPrimitiveValue:name forKey:#"name"];
[newPos didChangeValueForKey:#"name"];
[dic setObject:newPos forKey:name];
return newPos;
}
Could you help me to find the problem?
Best regards,
Timofey.
The error is caused by forming a relationship between managedObjects that don't share the same persistent store. You can do that by:
Creating a managed object with initialization without inserting it into a context.
Deleting a managed object from a context while retaining it in another object e.g. array, and then forming a relationship with it.
Accidentally creating two Core Data stacks so that you have two context and two stores.
Confusing configurations in a multi-store context.
I don't see any part of the code you provided that would trigger the problem.
It turns out, that it is wrong to pass NSManagedContext to a thread different from the one it was created in. Instead, one should pass the NSPersistenceStroreCoordinator to another thread, and create a new managed object context there. In order to merge the changes into the "main" context, one should save the other thread's context, receive the notification on the completion of the save on the main thread and merge the changes (see apple docs regarding Core Data and concurrency, can't give you the link, because i read it in Xcode). So here are the changes i made to my code to make it work (only posting the changed lines):
— (void) processStringsInBackground:(NSDictionary *) params {
NSFetchRequest *wordStringsReq = [params objectForKey:#"wordStringsReq"];
NSPersistentStoreCoordinator *coordinator = [params objectForKey:#"coordinator"];
NSManagedObjectContext *localContext = [[NSManagedObjectContext alloc] init];
[localContext setPersistentStoreCoordinator:coordinator];
(all the references to the managedObjectContext were replaced by localContext
And on the main thread, i call this method thusly:
.......
NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:req, #"wordStringsReq", persistentStoreCoordinator, #"coordinator", nil]; //the params i pass to the background method
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(handleNotification:) name:#"NSManagingContextDidSaveChangesNotification" object:nil]; //register to receive the notification from the save
[self performSelectorInBackground:#selector(processStringsInBackground:) withObject:dict];
}
- (void) handleNotification:(NSNotification *) notific {
NSLog(#"got notification, %#", [notific name]);
[managedObjectContext mergeChangesFromContextDidSaveNotification:notific];
}
Good luck!
Good answers, though a bit dated. The fine documentation notes that the main NSManagedObjectContext should never be used in worker threads. Instead, create a separate NSManagedObjectContext private to the worker using the "main" MOC as a parent, and then that instead. Here's the relevant "Concurrency" page from the Core Data Programming Guide:
https://developer.apple.com/library/prerelease/ios/documentation/Cocoa/Conceptual/CoreData/Concurrency.html
Snippet (Swift)
let jsonArray = … //JSON data to be imported into Core Data
let moc = … //Our primary context on the main queue
let privateMOC = NSManagedObjectContext(concurrencyType: .PrivateQueueConcurrencyType)
privateMOC.parentContext = moc
privateMOC.performBlock {
for jsonObject in jsonArray {
let mo = … //Managed object that matches the incoming JSON structure
//update MO with data from the dictionary
}
do {
try privateMOC.save()
} catch {
fatalError("Failure to save context: \(error)")
}
}
I have an Object bound to the user interface with a NSObjectController. I am able to archive the Object and unarchive it later. This works fine so far. In the Debugger I can see the object holds the data I saved in a previous session. The remaining problem is: The user interface does not refresh. I guess I have to tell the NSObjectController somehow he has to deal with an other object. But I don't know how. I tried newObject but that did not work at all.
At the moment my code looks like this:
if ([aOpenPanel runModal] == NSOKButton)
{
NSString *filename = [aOpenPanel filename];
rpgCharacter = [NSKeyedUnarchiver unarchiveObjectWithFile:filename];
// [myCharacterController DoSomething] ???
}
rpgCharacter should be the object for the myCharacterController.
What you are doing is setting the rpgCharacter iVar directly. In order to trigger KVO you need to do this in a different way either:
if you are using Objective-C 2.0 and property syntax:
if ([aOpenPanel runModal] == NSOKButton)
{
NSString *filename = [aOpenPanel filename];
self.rpgCharacter = [NSKeyedUnarchiver unarchiveObjectWithFile:filename];
}
or, if you are using KVC directly and have a correctly named setter:
if ([aOpenPanel runModal] == NSOKButton)
{
NSString *filename = [aOpenPanel filename];
[self setRpgCharacter:[NSKeyedUnarchiver unarchiveObjectWithFile:filename]];
}