I've created a SQLite database that contains records from some JSON using this tutorial, and I want to use MagicalRecord to query it.
MagicalRecord sees the NSManagedObject (BlogPost) and can create records, but it doesn't see the prepopulated records, so I'm guessing it's not seeing the SQLite file I've added. I've verified that the SQLite database does indeed contain rows using a SQLite client.
In application:didFinishLaunchingWithOptions:, I've put:
[MagicalRecord setupCoreDataStackWithStoreNamed:#"DBG.sqlite"];
And in applicationWillTerminate::
[MagicalRecord cleanUp];
When I call [BlogPost MR_findAll] in a controller, it returns an empty set. DBG.sqlite is at the root of the project directory, and I've tried putting it in "Copy Bundle Resources", but blogPosts still returns an empty set.
Any ideas?
The issue ended up being that the preloaded SQLite db needs to be copied to the default path of the application's db:
NSArray *paths = [[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask];
NSURL *documentPath = [paths lastObject];
NSURL *storeURL = [documentPath URLByAppendingPathComponent:#"DBG.sqlite"];
if (![[NSFileManager defaultManager] fileExistsAtPath:[storeURL path]]) {
NSURL *preloadURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:#"DBG" ofType:#"sqlite"]];
NSError* err = nil;
if (![[NSFileManager defaultManager] copyItemAtURL:preloadURL toURL:storeURL error:&err]) {
NSLog(#"Error: Unable to copy preloaded database.");
}
}
This should be placed just before [MagicalRecord setupCoreDataStackWithStoreNamed:#"DBG.sqlite"];.
Related
Problem: After long time running with no issues, my database is giving me a headache, it just wont stay at its place in the NSDocumentDirectory. The Database strangely disappears.
I never clear the documents-folder or delete anything. It only contains the database and saves some images in there which get downloaded if the user wants to keep them.
Has anybody an idea what could be going on?
after 3 days of struggling with this problem I can't come up with a possible solution, so please help me! :(
in my Database-Singleton I have the following init-Method
- (id)initWithName{
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDir = [documentPaths objectAtIndex:0];
databasePath = [documentsDir stringByAppendingPathComponent:kDatabaseName];
//kDatabaseName = nameOfDatabase.db
[self checkAndCreateDatabase];
return self;
}
and the checkAndCreateDatabase - method:
- (void) checkAndCreateDatabase{
// Check if the SQL database has already been saved to the users phone, if not then copy it over
BOOL success;
// Create a FileManager object, we will use this to check the status
// of the database and to copy it over if required
NSFileManager *fileManager = [NSFileManager defaultManager];
// Check if the database has already been created in the users filesystem
NSURL *urlpath = [NSURL fileURLWithPath:databasePath];
NSError *error = nil;
[urlpath setResourceValue: [NSNumber numberWithBool: YES]
forKey: NSURLIsExcludedFromBackupKey error: &error];
success = [fileManager fileExistsAtPath:databasePath];
// If the database already exists then return without doing anything
if(success && sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK)
{
NSLog(#"database opened");
sqlite3_close(database);
return;
}
else{
sqlite3_close(database);
NSLog(#"Database was created");
}
// If not then proceed to copy the database from the application to the users filesystem
// Get the path to the database in the application package
NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName];
//NSString *databasePathFromApp = [[NSBundle mainBundle] pathForResource:databaseName ofType:#"sqlite3"];
// Copy the database from the package to the users filesystem
[fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];
if ([self createTables]){ //creates tables of DB, works fine
NSLog(#"Tables were created");
} else {
NSLog(#"Database failed to create and open");
}
}
This code worked for a year straight. and suddenly when i needed to do some updates, the database was not saved anymore.
After a lot of troubleshooting I found out the database is being created in the Documents folder, but when i try to access the exact same path (cause i don't touch the variables) it disappears, with it's tables.
I tried different versions of my repository, all of them seem to have the problem. I really am getting mad. :(
Are you persisting the databasePath between app launches? In iOS 8 the DocumentsDirectory (and all the others, Caches, tmp, etc) became dynamic - - their name changes in between every app launch. So if you're storing the absolute path anywhere in your app it will be invalid the next time the app launches. If this is the case, a good way to fix it is to store the path relative to the DocumentsDirectory and whenever you need it just call
NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
and append your path to that.
Help this helps.
I've made an app that is relying on reading and writing a plist-file. This works well when I'm running the app in the iPhone simulator, but doesn't work at all when I'm testing it on my iPhone. I've also made a pre made text file in .txt format with demo data. The app works when I'm running this file.
All the reading and writing is done in a class that looks like this:
-(void)saveArray:(NSMutableArray *)inputArray
{
albumArray = inputArray;
NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentFolder = [path objectAtIndex:0];
NSString *filePath = [documentFolder stringByAppendingFormat:#"albums.plist"];
[albumArray writeToFile:filePath atomically:YES];
}
Update: Changed the string from "stringByAppendingFormat" to "stringByAppendingPathComponent" and it seems to work now. Thanks a lot! You guys made my day made.
Are you sure, that the folders already exist?
Here is a function i'm using to get the path to my file:
- (NSString*) pathToSavedAlbums
{
NSURL *applicationSupportURL = [self applicationDataDirectory];
if (! [[NSFileManager defaultManager] fileExistsAtPath:[applicationSupportURL path]])
{
NSError *error = nil;
[[NSFileManager defaultManager] createDirectoryAtPath:[applicationSupportURL path]
withIntermediateDirectories:YES
attributes:nil
error:&error];
if (error)
{
NSLog(#"error creating app support dir: %#", error);
}
}
NSString *path = [[applicationSupportURL path] stringByAppendingPathComponent:#"albums.plist"];
return path;
}
Check the spelling of the plist name as well as the case, device is case sensitive for docs but simulator isn't. Also try deleting the app from the device and reinstalling it ?
writeToFile:atomically: returns a bool, so check that to see if it fails to even write to the path. Check the file path string and ensure this is where you want it to go.
Learning to use coreData. Currently looking at Stanford's CS193P Lecture 14, which is very helpful. I have successfully set up a working app with core data persistence, using a ManagedDocument.
This code below is run every time the app starts. My confusion is: how do we know that the url for the document is correct? How does it know that "lastObject" will always be the URL for the saved document?
if (!myManagedDocument) {
NSURL *url = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
url = [url URLByAppendingPathComponent:#"theDatabase"];
myManagedDocument = [[UIManagedDocument alloc]initWithFileURL:url];
}
This code below will open the document, or create/save it if it has not already been saved previously.
if (![[NSFileManager defaultManager] fileExistsAtPath:[myManagedDocument.fileURL path]]) {
[myManagedDocument saveToURL:myManagedDocument.fileURL forSaveOperation:UIDocumentSaveForCreating completionHandler:^(BOOL sucess) {
[self getInfoFromDatabase];
}];
} else if (myManagedDocument.documentState == UIDocumentStateClosed) {
[myManagedDocument openWithCompletionHandler:^(BOOL sucess) {
[self getInfoFromDatabase];
}];
} else if (myManagedDocument.documentState == UIDocumentStateNormal) {
[self getInfoFromDatabase];
}
Depending on the directory and domainMask argument, URLsForDirectory can return
an array of several URLs. For example, on OS X,
NSArray *urls = [[NSFileManager defaultManager] URLsForDirectory:NSApplicationSupportDirectory inDomains:NSAllDomainsMask];
returns
(
file://localhost/Users/<user>/Library/Application%20Support/,
file://localhost/Library/Application%20Support/,
file://localhost/Network/Library/Application%20Support/
)
But in your case, on iOS,
NSArray *urls = [[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask];
returns an array of exactly one URL, which is the document directory inside the
application sandbox. On the simulator, this would look like
(
file://localhost/Users/<user>/Library/Application%20Support/iPhone%20Simulator/5.0/Applications/AAAAAAAA-BBBB-CCCC-DDDD-EEEEEEEEEEEE/Documents/
)
So it does not matter if you take the first or last object of that array.
The code just assumes that the managed document is saved in the document directory
of the application sandbox.
I have a simple piece of code where I connect my sqliteDb.
My sqlite3_prepare_v2 though repeatedly fails. I narrowed it down to the following piece of code:
NSString *sqLiteDb = [[NSBundle mainBundle] pathForResource:#"xyz" ofType:#"sqlite3"];
sqLiteDb returns null. I don't know why - tried everything I could and followed many threads.
Really struggling here - please help.
Are you sure your xyz.sqlite3 file is included in the correct Target Membership? If it is not included, then it will not be copied to your bundle when building.
Try this
in.h file
NSString *databasePath;
in .m file
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDir = [documentPaths objectAtIndex:0];
databasePath = [documentsDir stringByAppendingPathComponent:#"dbname.sqlite"];
[self checkAndCreateDatabase];
-(void) checkAndCreateDatabase
{
// Check if the SQL database has already been saved to the users phone, if not then copy it over
BOOL success;
// Create a FileManager object, we will use this to check the status
// of the database and to copy it over if required
NSFileManager *fileManager = [NSFileManager defaultManager];
// Check if the database has already been created in the users filesystem
success = [fileManager fileExistsAtPath:databasePath];
// If the database already exists then return without doing anything
if(success) return;
// If not then proceed to copy the database from the application to the users filesystem
// Get the path to the database in the application package
NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName];
// Copy the database from the package to the users filesystem
[fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil];
}
I am a beginner using Objective-C. I used the following code to move a file to iCloud but it gives an error that The operation could not be completed. The file exists.
//store the file locally in document folder
NSArray *docPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *filePath = [docPaths objectAtIndex:0];
filePath = [filePath stringByAppendingString:#"/"];
filePath = [filePath stringByAppendingString:fileName];
NSString *writeError = nil;
NSData * fileData = [NSPropertyListSerialization dataFromPropertyList:dataDic format:NSPropertyListXMLFormat_v1_0 errorDescription:&writeError];
if ([fileData writeToFile:filePath atomically:YES]) {
NSLog(#"Server file is stored locally");
}else {
NSLog(#"%#", writeError);
}
// store the file in iCloud folder
NSURL *ubiquitousURL = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil];
NSString *tmpubiquitousURL = ubiquitousURL.absoluteString;
tmpubiquitousURL = [tmpubiquitousURL stringByAppendingString:fileName];
NSURL *ubi2 = [[NSURL alloc] initWithString:tmpubiquitousURL];
[[NSFileManager defaultManager] setUbiquitous:YES itemAtURL:filePathURL destinationURL:ubi2 error:&error];
I used the following to remove the file from iCloud but it gives an error that Cannot disable syncing on an un-synced file.
[[NSFileManager defaultManager] setUbiquitous:NO itemAtURL:filePathURL destinationURL:ubi2 error:&error];
I checked the availability of iCloud in my app delegate and it's available. The file is an XML file (.plist) and I have a local copy stored in NSDocumentDirectory.
Overall, I want to sync that file in iCloud so it will be accessible on all devices using my app. I have been struggling with this for 2 days, so if you could help me to resolve the problem I would appreciate it.
Note: I would rather not to use UIDocument, however, if that is the only option please let me know.
I also have the same problem while using the code
[[NSFileManager defaultManager] setUbiquitous:NO itemAtURL:filePathURL destinationURL:ubi2 error:&error];
you have to change the code like below for this to work correctly
[[[NSFileManager alloc]init]setUbiquitous:YES itemAtURL:filePathURL destinationURL:ubi2 error:nil];
this code is for moving a file to icloud, also you should change the name of the file you are moving. It should not be same.