I am trying to create a nested collection view. First I did for one level.
Created a data model class with String header. In app delegate created an array sectionTitle. Now in the nib, I added collection view & array controller and did all the bindings following this guide. Next in awakeFromNib I populated some random data
- (void)awakeFromNib {
int idx = 0;
NSMutableArray *sectionTitle = [[NSMutableArray alloc] init];
while (idx < 1) {
HeaderModel *header = [[HeaderModel alloc] init];
[header setHeader:[NSString stringWithFormat:#"Section %d", idx]];
[sectionTitle addObject:header];
idx++;
}
[self setHeaderData:sectionTitle];
}
Running it will give me 4 sections. I want to achieve similar layout as this. Section title, under it another collection of items. The answer given there only hints at using Nested collection view.
So I added another collection view in the first view prototype. Then I followed the same approach what I did for the first view(with different data model and array).
- (void)awakeFromNib {
int idx = 0;
NSMutableArray *sectionTitle = [[NSMutableArray alloc] init];
NSMutableArray *groupData = [[NSMutableArray alloc] init];
while (idx < 1) {
HeaderModel *header = [[HeaderModel alloc] init];
DataModel *name = [[DataModel alloc] init];
[header setHeader:[NSString stringWithFormat:#"Section %d", idx]];
[name setName:[NSString stringWithFormat:#"Name %d", idx]];
[sectionTitle addObject:header];
[groupData addObject:name];
idx++;
}
[self setHeaderData:sectionTitle];
[self setData:groupData]; //NSCollectionView item prototype must not be nil.
}
But now I get the error NSCollectionView item prototype must not be nil.
How do I resolve this ?
I have just answered a similar question here
But somehow by inserting the second NSCollectionView with I.B, you get a corrupted prototype for your inner NSCollectionViewItem. Simply try to extract each associated NSView into its own .xib
Related
I've created a small test project to play with NSOutlineView before using it in one of my projects. I'm successful in displaying a list of items with children using a NSTreeController who's content is bound to an Array.
Now while I created this object it took me ages to realize that my array contents would only show up if i created them in my init method:
- (id)init
{
self = [super init];
if (self) {
results = [NSMutableArray new];
NSMutableArray *collection = [[NSMutableArray alloc] init];
// Insert code here to initialize your application
NSMutableDictionary *aDict = [[NSMutableDictionary alloc] init];
[aDict setValue:#"Activities" forKey:#"name"];
NSMutableArray *anArray = [NSMutableArray new];
for (int i; i<=3 ; i++) {
NSMutableDictionary *dict = [NSMutableDictionary new];
[dict setValue:[NSString stringWithFormat:#"Activity %d", i] forKeyPath:#"name"];
[anArray addObject:dict];
}
results = collection;
}
return self;
}
If I put the same code in applicationDidFinishLaunching it wouldn't show the items.
I'm facing the same issue now when trying to add items to the view. My understanding of using the NSTreeController is that it handles the content similar to what NSArrayController does for a NSTableView (OutlineView being a subclass and all). However, whenever I use a KV compliant method to add items to the array the items do not show up in my view.
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
NSMutableDictionary *cDict = [[NSMutableDictionary alloc] init];
[cDict setValue:#"Calls" forKey:#"name"];
[results addObject:cDict];
[outlineView reloadData];
}
I've also tried calling reloadData on the outlineview after adding an object, but that doesn't seem to be called. What am I missing?
Here's a link to my project: https://dl.dropboxusercontent.com/u/5057512/Outline.zip
After finding this answer:
Correct way to get rearrangeObjects sent to an NSTreeController after changes to nodes in the tree?
It turns out that NSTreeController reacts to performSelector:#selector(rearrangeObjects) withObject:afterDelay:
and calling this after adding the objects lets the new objects appear.
I have the following core data setup.
Data Setup
I have created an array controller called "SongsInMedleys" which is configured to contain the content of the SongsInMedleys with a specific medleyid.
I have created a view based Tableview which are bind to the SongsInMedleys array controller.
That is working fine, and I have managed to get the set the song title in a label by binding to Table Cell View and using objectValue.withSongs.title in the Model Key Path.
Now to my issue:
I would like to create a collection view inside the Table Cell View with all the verses to the related song. (objectValue.withSongs.withVerses)
Any suggestion to how I can do that???
Model of what I am trying to create :
Model
After some research I gave up try adding a collection view inside the tableview.
Insted I added my verses manually in the subclass of the NSTableCellView
-(void) setObjectValue:(id)objectValue {
if (objectValue != nil)
{
[super setObjectValue:objectValue];
SongsInMedleys *Sim = objectValue;
Songs *song = Sim.withSongs;
scrollView *scrollview = [[scrollView alloc] initWithFrame:NSMakeRect(10,5,[self frame].size.width-30,145)];
int addverses = 0;
for (VersesInSongs *verse in song.withVerses)
{
if ([verse.lyric length] > 0) {
addverses += 1;
}
}
NSView *view = [[NSView alloc] initWithFrame:NSMakeRect(5, 10, ((addverses * (169+5))+5), 140)];
int x = 5;
NSSet *Verses = song.withVerses;
NSSortDescriptor *sortVerses = [[NSSortDescriptor alloc] initWithKey:#"number" ascending:YES];
NSArray *sortedVerses = [Verses sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortVerses]];
for (VersesInSongs *verse in sortedVerses)
{
if ([verse.lyric length] > 0) {
verseBox *box = [[verseBox alloc] initWithFrame:NSMakeRect(x, 10, 169, 130)];
[box setSong:song];
[box setVerse:verse];
[view addSubview:box];
x = x + 169+5;
}
}
[scrollview setDocumentView:view];
[self addSubview:scrollview];
}
}
I have a table wherein every row contains a textfield.After i entertext in all the rows which are text fields i want to retrieve the data into an array.Can any one tell me the idea of retrieving the data from every row which are textfields?
I cannot believe you. Bad grammar and no research.
To get an array of all text fields, I would do:
NSArray *subviews = self.view.subviews;
NSMutableArray *textFelds = [[NSMutableArray alloc]init];
NSMutableArray *indexPaths = [[NSMutableArray alloc]init];
NSObject *obj;
for (obj in subviews) {
if ([obj class] == [UITextField class]) {
[textFields addObject:obj];
CGPoint location = obj.center;
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:location];
[indexPaths addObject:indexPath];
}
}
It first gets all of the subviews of the main view, then determines if they are text fields. If they are textFields, it adds that to an array and also gets the indexPath.
I hope I have answered your question
You are having the details like, which row has text fields, which are not.
You can get this feature by using two different king of cells
static NSString *CellIdentifierNormal = #"Cell";
static NSString *CellIdentifierTF = #"Cell";
UITableViewCell *cell;
if(indexPath.row %2 == 0){ //Example
cell = (UITableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifierNormal];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifierNormal] autorelease];
}
} else {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifierTF] autorelease];
TF *tf = [[TF alloc] init];
tf.tag = 10;
}
In Text field row case, should not use the dequeueReusableCellWithIdentifier it re uses the existing cells, so that the text fields data may corrupt [This will happen when your data rows size greater than the table size - height]
Whenever you want collect the data from TF's
Just run loop with number of rows in table, and check same condition as you are using in creating cell.
Access the cell, and TF from cell by using tag number [10] from TF get the text
I have the problem that I can't get the Data from one of my classes to the other...
To do this I created this method in the class I am initializing (angebotPage):
- (id) initWithDictionary:(NSDictionary *)dictionary
{
self = [super init];
if (self) {
dict = [dictionary retain];
}
return self;
}
The call from the other class looks like this:
angebotPage *page;
angebotPDF = [[PDFDocument alloc] init];
page = [[angebotPage alloc] initWithDictionary:dictionary];
The Error I get is EXC_BAD_ACCESS in the line where I do:
dict = [dictionary retain];
But why? I need to retain it cause I will use it for the next program steps.. But without retaining I can't use it (EXC_BAD_ACCESS comes elsewhere...)
I recommend that you use a property for dict instead.
#property (retain) NSDictionary *dict;
And then assign the dictionary with self.dict = dictionary. This is assuming all the objects in dictionary are correctly retained in the first place. Try with an empty dictionary if in doubt.
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)")
}
}