I'm not sure that I completely understand how Core Data works on iOS.
I have a large JSON file which I have parsed and imported into core data. This generates an sqlite file. I need this file to be included with the app but every time I delete the app from the device - I have to run the JSON parse script again to create a new sqlite file on the device. I want to be able to exclude the JSON file from the application bundle and dont want to run the parsing script on first use.
How do I go about doing this? Am I doing something wrong?
You will need to create the sqlite file (using your app if you like), then copy it into your project and deploy it with the app. You will also need to add some code to move the file into your documents directory when your app runs for the first time. It can be a simple if file doesn't exist then copy it script.
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *DB = [[paths lastObject] stringByAppendingPathComponent:#"myDB.sqlite"];
if (![fileManager fileExistsAtPath:DB]) {
NSString *shippedDB = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"myDB.sqlite"];
[fileManager copyItemAtPath:shippedDB toPath:DB error:&error];
}
I use this method to ship out pre-built sqlite files, although I haven't used it when CoreData is managing the sqlite file.
Related
I have locally saved one xml file and showing the details by using NSXmlParser(Which is stored in Resource folder). But, now i want to download new xml from url(from client side) and need to store that new xml file in local and also need to delete existing one from the application. How can i do this? Any suggestions? There is any sample code/project for reference? Please help me. Thanks for reading my poor english. Thanks is advance.
although u can delete file from yr resource directory and save new one but the my way is to perform file operation mostly on app diretories like document directory or cache directory.
first u will to save yr xml file from app resource to cache directory then access file from there.And u can also remove file from resource directory ,its no longer needed.
any new file available in internet then first remove old one from cache and add new one to cache directory.
whole thing is as follows:-
//get your cachedirectory path
NSArray *imagepaths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString *cachdirectory = [[NSString alloc] initWithString:[imagepaths objectAtIndex:0]];
//first save your file from resource directory to app's cache directory
NSString * path = [[NSBundle mainBundle] pathForResource:#"fileinresource" ofType:#"xml"];
NSData *filedata = [NSData dataWithContentsOfFile:path];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *savename = [cachdirectory stringByAppendingPathComponent:#"mynewfile.xml"];
[fileManager createFileAtPath:savename contents:filedata attributes:nil];
//remove file from resource directory
[fileManager removeItemAtPath:path error:nil];
//new file from internet is avilable then do following:first remove old file from cache
[fileManager removeItemAtPath:cachdirectory error:nil];
//save new file from internet
NSData *newfiledata=[NSData dataWithContentsOfURL:[NSURL URLWithString:myxmlurlstringpath]];
[fileManager createFileAtPath:savename contents:newfiledata attributes:nil];
I want to add a sqlite database to XCode 4 (applies to XCode 3 too). Tutorials state adding the .db file to the resources folder, and I suppose this gets copied to ~/Library/Application Support/iPhone Simulator/4.2/Applications/{some-id}/Documents/ during build where you can find the file with NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)
etc.
However, XCode 4 doesn't have a visible resources folder.
I've tried adding a file with the Add File... command, and then it appears in Targets > AppName > Copy Bundle Resources, but always an empty .db file appears in the above documents folder (which I then manually replace - obviously not the correct approach!)
(due to the nature of the data I'm sticking with sqlite over CoreData)
you have to start adding your db in your project-xcode, so it will be added in your bundle folder, where you can find it via code:
[NSBundle mainBundle]
It's the only folder where you can add files via xcode when you "build" your app (eventually with subfolders, but not "system" folders as "documents") now you just need to keep in mind that the main bundle folder is just "read only", so you cant use your db there with write privileges.
So the normal way is:
1) when you wanna use your db, check via code if it exists in the app:documents folder.
Of course the first time it doesn't, so
2) copy it from the main bundle
- (BOOL)transferDb {
NSError **error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:#"yourData.db"];
NSFileManager *fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath: path])
{
NSString *bundle = [[ NSBundle mainBundle] pathForResource:#"preferenze" ofType:#"plist"];
[fileManager copyItemAtPath:bundle toPath:path error:error];
return YES;
}
return NO;
}
3) use it (r/w) in the documents folder
ps:
and (of course) keep in mind that when you use/edit/write the db in iPhone/simulator, maybe adding records, the one in the main bundle and of course the one in your mac/project won't be updated, no records will be added to it, so if for any reason you delete your app on iPhone/simulator (or "clean all targets" by the xCode "build" menu) the check/copy method will copy the "virgin" db in the documents folder again, so you will loose all your changes...
Be careful with the amount of data you are putting into the Documents folder, this is meant for user data and since this data will be backed up using iCloud Apple have limited the amount of data an app can store and use in the Documents folder.
My app was rejected for using a 6MB SQLite database in this way. Instead copy it to the caches directory: NSCachesDirectory.
Or prevent the file from being backed up: https://developer.apple.com/library/ios/#qa/qa1719/_index.html
this must be easy but I want to put a file in the Documents folder which is read in at start up. I have the code on how to read and have confirmed its looking in the correct directory. However the file I have ,RootList.txt when saved in the Resources folder in xcode, is stored under the Root.app folder and the Documents folder is empty. Therefore its not finding this file when I start the app.
Is there a way to ensure a file is built into the Documents directory at start up (I'm running this in the simulator).
The alternative is a plist which works fine as well but I'm just curious.
In these situations I follow this approach:
First save your RootList.txt in Resources folder in xCode.You have nothing in your Documents folder, yet.
In the beginning of your applicationDidLaunch call, do:
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *docsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *path = [docsDirectory stringByAppendingPathComponent:#"RootList.txt"];
if(![fileManager fileExistsAtPath:path])
{
NSData *data = [NSData dataWithContentsOfFile:[[[NSBundle mainBundle] resourcePath] stringByAppendingString:#"/RootList.txt"]];
[data writeToFile:path atomically:YES];
}
Now, your file is in Documents folder at startup.
i deployed my App to my iPhone and get
Unknown error calling sqlite3_step (8: attempt to write a readonly database) eu
on Insert / Update Statements.
On the Simulator it all works like it should.
My sqlite Database is placed in the Resource Folder (Xcode).
Thanks for help!
Your application bundle is not writable on the iPhone. You MUST copy the file somewhere else, like your documents folder. It works in the simulator because the Mac does not enforce all the sandboxing restrictions the iPhone does.
You can copy your database from the application bundle directory to the Documents directory in viewDidLoad. You can read/write from/to your database in the Documents directory after this. Of course, you need to check if the database in the Documents directory exist before you do the copy in order not to overwrite it the next time you bring up the app.
Assuming you have defined your database name '#define kFilename #"yourdatabase.db"' in the .m file.
In viewDidLoad add:
// Get the path to the main bundle resource directory.
NSString *pathsToReources = [[NSBundle mainBundle] resourcePath];
NSString *yourOriginalDatabasePath = [pathsToResources stringByAppendingPathComponent:kFilename];
// Create the path to the database in the Documents directory.
NSArray *pathsToDocuments = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [pathsToDocuments objectAtIndex:0];
NSString *yourNewDatabasePath = [documentsDirectory stringByAppendingPathComponent:kFilename];
if (![[NSFileManager defaultManager] isReadableFileAtPath:yourNewDatabasePath]) {
if ([[NSFileManager defaultManager] copyItemAtPath:yourOriginalDatabasePath toPath:yourNewDatabasePath error:NULL] != YES)
NSAssert2(0, #"Fail to copy database from %# to %#", yourOriginalDatabasePath, yourNewDatabasePath);
}
Good luck!
aobs
I want copy some files to Library or Document in the Product directory,
but when I add a build phase and select Products Directory in destination and input my subdir it's like Library/xxx/.
When I run the App in the simulator, I found nothing in the destination and if I set the destination to Resources, it will be there.
Can you please tell me why this is happening and how I can make it?
The documents directory should only be accessed at runtime. To my knowledge you cannot copy items there during building. What you should do is store those objects that you want in the Documents directory within your bundle and then copy them upon first launch.
Interesting question. I don't know if you can do this as part of the build phase.
To get something into the Documents directory, I have a method that runs at app startup like this:
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writablePath = [documentsDirectory stringByAppendingPathComponent:#"filename.txt"];
BOOL success = [fileManager copyItemAtPath:defaultDBPath writablePath error:&error];
That's an incomplete fragment but you probably get the idea. The important thing is the NSDocumentDirectory constant.
Add a new build phase -> New Copy Files Build Phase in Target