(void) connection:(NSURLConnection )connection didReceiveData:(NSData )data
{
[self.receivedData appendData:data];
// convert data to array
// ??? the below is not working
NSMutableArray *receivedDataAsArray = [NSPropertyListSerialization
propertyListFromData:self.receivedData
mutabilityOption:NSPropertyListImmutable format:nil errorDescription:nil];
}
I use the above with NSURLConnection to get the data (serialized array). I want to convert it to an NSMutableArray. While the above doesn't return an error, it doesn't return a populated array either (though I am definitely receiving data). Any help as to how to properly convert NSData/NSMutableData to NSArray/NSMutableArray?
Use NSKeyedArchiver for archiving object to data.
NSKeyedUnarchiver for unarchiving object from data:
NSArray *object = [NSKeyedUnarchiver unarchiveObjectWithFile:self.receivedData];
Related
I'm downloading often identical data on multiple calls to different URLs in RESTKit. The first call maps fine, but the subsequent calls then replace the first call's entities.
The behaviour that I want is to have the objects unique to within their parent entity, so even if the data looks the same I still want a new object to be created, but at the moment it looks like RESTKit wants them to be unique across the entire database. There's no unique key to do this in the data I'm downloading, the objects are literally identical. Below is the code I'm using to create the operation. How do I set this up to allow duplicates?
NSMutableURLRequest *request = [self requestWithURL:URL];
[request setHTTPMethod:#"GET"];
RKHTTPRequestOperation *requestOperation = [[RKHTTPRequestOperation alloc]initWithRequest:request];
RKResponseDescriptor *responseDescriptor = [INKResponseDescriptorFactory journeySegmentDescriptorForPath:URL.path inStore:[RKObjectManager sharedManager].managedObjectStore];
RKManagedObjectRequestOperation *operation = [[RKManagedObjectRequestOperation alloc] initWithHTTPRequestOperation:requestOperation
responseDescriptors:#[responseDescriptor]];
operation.managedObjectContext = [self.objectManager context];
operation.managedObjectCache = self.objectManager.managedObjectStore.managedObjectCache;
operation.savesToPersistentStore = NO;
[operation setCompletionBlockWithSuccess: ^(RKObjectRequestOperation *requestOperation, RKMappingResult *mappingResult)
{
success();
} failure: ^(RKObjectRequestOperation *requestOperation, NSError *error) {
failure(error);
}];
[self.objectManager enqueueObjectRequestOperation:operation];
Figured out a way to do this.
Each time I'm updating the data, even though the entities I get contain identical data, I'm retrieving them from a different url.
RESTKit allows you to retrieve metadata from you calls and map this into your managed objects properties.
So what I've done is map the URL I used for the request into a property and used that as well as an identifier, which is unique within this call's returned objects, to make objects which will be unique throughout the database.
So my mapping now looks like this:
RKEntityMapping *seatMapping = [RKEntityMapping mappingForEntityForName:#"Seat" inManagedObjectStore:store];
[seatMapping addAttributeMappingsFromDictionary:#{ #"designator" : #"designator",
#"status" : #"status",
#"#metadata.HTTP.request.URL" : #"requestURL"}];
seatMapping.identificationAttributes = #[#"requestURL", #"designator"];
I am trying to store the Output of [Sectioninfo Objects] into an array
NSArray *currentCategory = [sectionInfo objects];
Although the OutPut that i get on NSLOG is as Follows :
"<Catalogue: 0x6da1d20> (
entity: Catalogue;
id: 0x6da1090 <x-coredata://894839B1-B485-4D64-8D46-99E388F00225/Catalogue/p3> ;
data: {\n comments = nil;\n
email = nil;\n
name = Shorts;\n
phone = 0;\n
picture = <ffd8ffe0 00104a46 49460001 01000001 00010000 ffe10058 45786966 00004d4d 002a0000 00080002 01120003 00000001 0001>;\n
price = 77;\n
shop = Shop;\n
website = nil;\n})"
I am Interested only in the Data Part
How Can i Extract it The Data Part only ?
& then I can add it to NSArray
Thanks for your Help
Since the question is tagged core-data, I assume you are talking about the section information you get from a NSFetchedResultsController via
id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex:section];
If that is the case, then the section info protocol specifies that objects returns an array of objects in that section. This array of objects will hold actual objects, just like the array of objects you get back from executing a fetch.
You can, thus, access them just like you would any other object. Hopefully, you have a subclass, so you can access the object via the appropriate properties.
Otherwise, you can use the KVC methods. From your log output, I assume data is a property of your object (probably a string).
NSArray *sectionObjects = [sectionInfo objects];
NSMutableArray *dataArray = [NSMutableArray arrayWithCapacity:sectionObjects.count];
for (NSManagedObject *object in sectionObjects) {
NSString *data = [object valueForKey:#"data"];
[dataArray addObject:data];
}
Or, you could do it more succinctly as:
NSArray *dataArray = [[sectionInfo objects] valueForKey:#"data"];
which returns an array with the result of applying the key to each object in the receiver.
I have created few entities in context for saving it in db using
AppCalendarEntity *appCalendar = [AppCalendarEntity getInstanceWithManagedDocument:manageDocument];
After adding a few entities I execute flowing fetch request
NSFetchRequest *requestToSeeIfCalendarWithIdExist = [NSFetchRequest fetchRequestWithEntityName:#"AppCalendarEntity"];
NSArray *result = [managedDocument.managedObjectContext executeFetchRequest:requestToSeeIfCalendarWithIdExist error:&InternalError] ;
It returns me the result including only the entities I have added in context using first command and NOT the entries already saved in database. I have made sure that at this stage the document state is UIDocumentStateNormal.
When I add this line to already open document (UIDocumentStateNormal) it returns me the expected result, i.e. it fetch results from db as well as memory context which has not yet been saved to db.
[managedDocument openWithCompletionHandler:^(BOOL success)
{
NSFetchRequest *requestToSeeIfCalendarWithIdExist = [NSFetchRequest fetchRequestWithEntityName:#"AppCalendarEntity"];
NSArray *result = [managedDocument.managedObjectContext executeFetchRequest:requestToSeeIfCalendarWithIdExist error:&InternalError] ;
}
My question is
1- I expect that the result of query should be the same in both cases. Why it is not so in the above case.
2- To me if document state is UIDocumentStateNormal I should not be calling "openWithCompletionHandler" in context to open the document. In this particular scenario what difference it is making in NSFetchRequest which gives me the desired result after adding this.
Please let me know if I'm getting wrong
Here is the complete code
This is the complete code of the function
+ (void ) saveCalendarArrayInDbIfItAlreadyDoesNotExist : (NSArray*) appCalendarArray managedDocument: (UIManagedDocument*) managedDocument completionBlock : ( void(^) (NSArray* ObjectSavedSuccesfully, NSError *InternalError)) handler
{
// i dont know why i have to do it :( if i dont add openWithCompletionHandler my query doesnt fetch result from db rather just do query in-memory context and not db
[managedDocument openWithCompletionHandler:^(BOOL success)
{
void (^completionHandler)(NSArray* , NSError* );
completionHandler = [handler copy ];
NSError *error = nil;
NSMutableArray *array = [[NSMutableArray alloc] init];
for (id appCalendar in appCalendarArray) {
if([appCalendar isKindOfClass:[AppCalendarEntity class]])
{
AppCalendarEntity *appCalendarEntity = (AppCalendarEntity*) appCalendar;
NSFetchRequest *requestToSeeIfCalendarWithIdExist = [NSFetchRequest fetchRequestWithEntityName:#"MyEntity"];
requestToSeeIfCalendarWithIdExist.predicate = [NSPredicate predicateWithFormat:#"identifier = %#", appCalendarEntity.identifier];
NSError *InternalError = nil;
[requestToSeeIfCalendarWithIdExist setShouldRefreshRefetchedObjects:YES];
NSArray *result = [managedDocument.managedObjectContext executeFetchRequest:requestToSeeIfCalendarWithIdExist error:&InternalError] ;
// "result" is different when we encapsulate it in openWithCompletionHandler and when we don't…….MY PROBLEM
if(result == nil)
{
// return error
}
// 1 object always return that depict the in memory(context) object we created but not saved. I expect it should be zero because no object has yet been saved to database..
else if(result.count > 1)
{
[managedDocument.managedObjectContext deleteObject:appCalendar];
}
else
{
[array addObject:appCalendarEntity];
}
}
else
{
// error handling
}
}
if (error != nil)
{
completionHandler (nil, error);
return;
}
// saving all the objects
[ managedDocument updateChangeCount:UIDocumentChangeDone ];
}
When using UIManagedDocument, you do not call save on the MOC because it implements auto-save. however, it needs to be told that an auto-save should take place at some point in the future.
Get rid of that call to openWithCompletionHandler in that function (I know it was just there for purposes of debugging this problem).
Replace
[managedDocument.managedObjectContext save:&InternalError ]
with
[managedDocument updateChangeCount:UIDocumentChangeDone];
This will notify the document that it can now be saved.
EDIT
First, I think you should get rid of the debugging hacks. You can add NSLog or NSAssert, but the rest of that stuff just makes it hard to tell why you want, and confuses the real issue.
Second, what is your real goal here? I can see the name of the method, and I can see the code, but they do not match.
There is so much "cruft" here, it is hard to understand your problem. I am going to repost your code, along with an edit to remove the "open" stuff, and annotate it with questions as code comments.
Hopefully, this change will help you solve your problem.
// First, the method name seems to indicate that some objects will be added
// to the database. however, the only database work in this method is removal.
// I don't get it.
+ (void ) saveCalendarArrayInDbIfItAlreadyDoesNotExist : (NSArray*) appCalendarArray managedDocument: (UIManagedDocument*) managedDocument
{
NSError *error = nil;
NSMutableArray *array = [[NSMutableArray alloc] init];
for (id appCalendar in appCalendarArray) {
if([appCalendar isKindOfClass:[AppCalendarEntity class]]) {
// OK, we are filtering the array of objects. We are only interested in
// objects of type AppCalendarEntity, and are going to use its identity
// property to look for objects of type MyEntity.
// What is the relationship between AppCalendarEntity and MyEntity?
AppCalendarEntity *appCalendarEntity = (AppCalendarEntity*) appCalendar;
NSFetchRequest *requestToSeeIfCalendarWithIdExist = [NSFetchRequest fetchRequestWithEntityName:#"MyEntity"];
requestToSeeIfCalendarWithIdExist.predicate = [NSPredicate predicateWithFormat:#"identifier = %#", appCalendarEntity.identifier];
NSError *InternalError = nil;
[requestToSeeIfCalendarWithIdExist setShouldRefreshRefetchedObjects:YES];
NSArray *result = [managedDocument.managedObjectContext executeFetchRequest:requestToSeeIfCalendarWithIdExist error:&InternalError];
// OK, now we just got a result from searching for a MyEntity, where
// its identifier is the same as the appCalendarEntity.
if(result == nil)
{
// return error
}
// 1 object always return that depict the in memory(context) object we created but not saved. I expect it should be zero because no object has yet been saved to database..
else if(result.count > 1)
{
// I am extremely confused by this code. First, why are you
// checking for more than 1 object? The method name indicates
// you are going to insert something. Furthermore, you are only
// deleting one object. How many do you expect? Also, why are
// you deleting an appCalendar? You were searching for a MyEntity.
// If an appCalendar is a MyEntity, then that's terrible naming.
// Furthermore, it would explain why you are finding it...
// because you create entities by inserting them in a MOC to
// begin with!
[managedDocument.managedObjectContext deleteObject:appCalendar];
}
else
{
// Even more confusion. You are adding this object to an internal
// array, not the database. Furthermore, you are doing it if there
// are either 0 or 1 MyEntity objects in the database with matching
// identifier.
[array addObject:appCalendarEntity];
}
}
}
// saving all the objects
// OK - but the only thing being saved are the ones you deleted...
[ managedDocument updateChangeCount:UIDocumentChangeDone ];
}
Finally, if my hunch is correct, and the calendar objects are actually MyEntity objects, they are already in the MOC - because that's how they get created. When you do a fetch, you can force the search to ignore pending changes (as noted in one of my previous comments) and only accept saved changes.
If you want to ignore pending changes,
fetchRequest.includesPendingChanges = NO;
#Jody Problem has been resolved and thank you for giving time to this question.
First let me address your confusions
1- Yes function is intended to save in the database and it is a helping function. The parameter "appCalendarArray" being passed to this function consist of entities that has already been created in context. I intentionally eliminated the logic since it involves communicating with external apis, parsing json etc etc. The code required for inserting entities in context has already been included in first part of the question.
AppCalendarEntity *appCalendar = [AppCalendarEntity getInstanceWithManagedDocument:manageDocument];
2- I eliminate the entities from context which has been constructed but not yet saved from context, based upon a column in database that should be unique. If we have identifier for object already in database, we do not want to resave it. So, I simply delete it from context. This function works as expected, entities are not re-saved in database. The last line do save the objects that are left in context if any. Most of the time there are a lot.
3- Sorry for mistyping AppCalendarEntity and MyEntity are the same.
Solution
I have added this flag fetchRequest.includesPendingChanges = NO; , delete db, restarted Xcode and it started working. Thank you for your persistence
I have an NSPersistentDocument subclass using NSManagedObject subclasses for my data.
When a new document is opened, I do some initializing of data structures (trivial amount of populating fields). What I've noticed is that the Untitled document gets autosaved, and when the application re-opens, that document gets loaded. If the application quits, the user doesn't (by default) get prompted with the save dialog. If the window closes, the user does.
First question:
I want to call up the save dialog when the user quits the application. I don't want this Untitled document hanging around (under normal circumstances). I either want it saved or trashed.
I attempted to fill out:
- (void)applicationWillTerminate:(NSNotification *)aNotification
In order to trigger the document to be saved. Calling save: on the context at this point gives an error. From what I can tell, this is because the user hasn't yet saved the file on their own. In addition, calling [self close]; or [[self windowForSheet] close]; close the window without saving.
How can I force the save dialog to come up? How can I trash the untitled document?
Second question (no, I can't count):
Since when the application starts, there may or may not be an Untitled document to deal with, I'm trying to keep track of the state in another model. I've already found that the initial data (to which I referred earlier) is present when the Untitled document came up. My other model has some metadata, including a success flag/state for the populated data. Once the populated data is all in place and correct, the state indicates as such. Unfortunately, while my populated data is being loaded when the app starts with a pre-existing Untitled document, the metadata class is not.
Please excuse the roughness of the code, at this point, I'm mucking it up until I can see that it's working how I want before I polish it back off:
- (bool) createGameState {
NSEntityDescription* description = [NSEntityDescription entityForName:[GameState name] inManagedObjectContext:[self managedObjectContext]];
NSFetchRequest* req = [[NSFetchRequest alloc] init];
[req setEntity:description];
NSError *error = nil;
NSArray *array = [[self managedObjectContext] executeFetchRequest:req error:&error];
[req release];
req = nil;
GameState* result = nil;
if (array) {
NSUInteger count = [array count];
if (!count) {
// Create the new GameState.
DebugLog(#"Creating GameState");
result = [NSEntityDescription insertNewObjectForEntityForName:[GameState name] inManagedObjectContext:[self managedObjectContext]];
[result setIsLoaded:[NSNumber numberWithBool:NO]];
} else {
if (count > 1) {
NSLog(#"WARNING: Potentially Corrupt Game State. found: %lu", count);
}
result = [array objectAtIndex:0];
if ([result isLoaded]) {
[self variantLoaded];
} else {
// In this case, we have an aborted set-up. Since the game isn't
// playable, just refuse to create the GameState. This will
// force the user to create a new game.
return NO;
}
}
} else {
DebugLog(#"error: %#", error);
}
[game setState:result];
return result;
}
Note that array is always present, and count is always zero. No, I'm not explicitly calling save: anywhere. I'm relying on the standard auto-save, or the user performing a save.
EDIT:
I installed the Core Data Editor app. It turns out the issue isn't on saving the data, but on loading it. (Note: Due to another issue, the app saves as binary when instructed to save as XML, which causes much head banging.)
I've broken it down to the simplest code, which should pick up all objects of type GameState in an array. It retrieves none, despite there clearly being objects of the appropriate type in the saved file:
NSManagedObjectContext* moc = [self managedObjectContext];
NSEntityDescription* entity = [NSEntityDescription entityForName:#"GameState" inManagedObjectContext:moc];
NSFetchRequest* req = [[NSFetchRequest alloc] init];
[req setEntity:entity];
NSError *error = nil;
NSArray *array = [moc executeFetchRequest:req error:&error];
Array is not null, but [array count] is 0.
At this point, I'm guessing it's something simple that I'm overlooking.
Second EDIT:
I added -com.apple.CoreData.SQLDebug 5 and saved as SQLite. The call to executeFetchRequest does not generate any debug logs. I do see the INSERT INTO ZGAMESTATE entry show up in the logs. It seems that executeFetchRequest is not getting passed to the backend.
Third EDIT (this one burns):
I created a new xcode project, using core data (as I had with the other). I copied just this one function (stubbing where necessary) and plopped a call to it in windowControllerDidLoadNib. In this new project, the code above works.
Found the problem.
I errantly was loading objects in Document's - (id) init call. Moved to windowControllerDidLoadNib (which is what I did in the test version) and it worked fine.
I have an application where I would like to exchange information, managed via Core Data, between two iPhones.
First turning the Core Data object to an NSDictionary (something very simple that gets turned into NSData to be transferred).
My CoreData has 3 string attributes, 2 image attributes that are transformables.
I have looked through the NSDictionary API but have not had any luck with it, creating or adding the CoreData information to it.
Any help or sample code regarding this would be greatly appreciated.
I would recommend that you convert the Core Data objects to an intermediate format like JSON before pushing it over the wire. I have written up the code on how to transform NSManagedObject instances into and out of JSON in this other post:
JSON and Core Data on the iPhone
NSManagedObject doesn't conform to the NSCoding Protocol so you can't convert a managed object straight to data.
Instead, you just need to add a method to the managed object subclass that returns a dictionary with the instance attributes and then on the receiver side, use those to create a new managed object in the local context.
Edit:
From comments:
Currently I have for the sending
side..
NSData* data;
NSString *str0 = [NSString stringWithFormat:#"%#",[[person valueForKey:#"PersonName"] description]];
NSString *str1 = [NSString stringWithFormat:#"%#",[[person valueForKey:#"alias"] description]];
NSMutableDictionary *taskPrototype = [NSMutableDictionary dictionary];
[taskPrototype setObject:str0 forKey:#"PersonName"];
[taskPrototype setObject:str1 forKey:#"alias"];
data = ?????;
//I do not know what to put here... [self mySendDataToPeers:data];
on the receiving side I have...
NSMutableDictionary *trial = [[NSMutableDictionary alloc] initWithData:data];
NSString *str0a = ???? NSString *str1a = ????
//I dont know what to put after this to retrieve the values and keys from the dictionary
You would simply reverse the process to create a managed object on the receiver.
NSMutableDictionary *trial = [[NSMutableDictionary alloc] initWithData:data];
NSManagedObject *person=[NSEntityDescription insertNewObjectForEntityForName:#"PersonEntity" inManagedObjectContext:moc];
[person setValue:[trial objectForKey:#"PersonName"] forKey:#"PersonName"];
[person setValue:[trial objectForKey:#"alias"] forKey:#"alias"];
.. and you're done.