Accessing assets in iOS7 with NSBundle - ios

I am having problems updating an app to iOS7 SDK. Before I've used iOS 6 SDK and accessed my mp3 file using a NSURL for the folder like this:
NSURL *folderURL = [[NSBundle mainBundle] URLForResource:#"" withExtension:#"" subdirectory:#"AudioGuide"];
Now, using the iOS 7 SDK I always get nil as the value for folderURL and my audio guide doesn't find the mp3's anymore.
I've already looked into the generated .app-Bundle for the simulator (in ~/Library/Application Support/...), and I can see the "AudioGuide" folder in the root. So it's definitly there.
I am not that iOS guru and didn't really follow iOS7 updates. Has there been any changes made on how to access own assets in an app? How do I access my files?

Apple doc for - (NSURL *)URLForResource:(NSString *)name withExtension:(NSString *)extension subdirectory:(NSString *)subpath
Returns the file URL for the resource file identified by the specified
name and extension and residing in a given bundle directory.
what that means is you can get the file URL with specific type in a given subdirectory, so you should use this method call with your file name and extension.
If you are trying to read the list of files under that directory, what you can do is bundle all of your audio files in a single zip or gzipped file and you extract it in your Documents or Application Support directory when it is accessed for the very first time, then you can read it using the code below.
NSArray *directories = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES);
NSString *directory = [directories objectAtIndex:0];
NSString *audioDirectoryPath = [directory stringByAppendingPathComponent:#"AudioGuide"];
NSArray *audioFiles = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:audioDirectoryPath];
Hope this helps!

Related

Writing big file on IOS [duplicate]

I save some run-time generated files inside the .app bundle of my iOS app. In the simulator it works fine, in the device it crashes:
Could create output files in the given shader cache path
'/var/mobile/Applications/CB064997-B40E-4FE3-9834-B3217CE33489/SimedTest.app/Ogre3D/assets/RTShaderLib/cache/
Is there a good overview of where I should and shouldn't put files - how to use Documents, Library and tmp, etc?
To clarify, these are files created at startup which pre-calculate some data to save time. IF they are not present they get created so it's fine they are deleted, but not while the app is running.
The bundle is read-only. You don't want to mess around with it for two reasons:
Code Signing: the signature is verified by against the contents of the bundle; if you mess around with the bundle, you break the signature.
App Updates: updates work by replacing the entire app bundle with a newly downloaded one; any changes you make will get lost.
Where you should save stuff:
Documents: if you want it to persist and be backed up
Library/Caches: if you just want to cache downloaded data, like profile pics; will be auto deleted by the system if it is low on room unless you specify with a special do-not-delete flag.
tmp: temporary files, deleted when your app is not running
For a full explanation check out File System Programming Guide and QA1719.
No, every time you change your bundle you invalidate your signature.
If you want to write files you`l need to write in the best folder depending on what you want to do with that file.
Documents folder for long duration files
Cache for small operations
and so on
EDIT
To get the path you`ll need something like this:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:#"filename.ext"];
With this path you can write or read like this:
write:
NSString *content = #"One\nTwo\nThree\nFour\nFive";
[content writeToFile:fileName atomically:NO encoding:NSStringEncodingConversionAllowLossy error:nil];
read:
NSString *content = [[NSString alloc] initWithContentsOfFile:fileName usedEncoding:nil error:nil];

Accessing locally stored (hidden from user, under library) file in iOS

Here is the NSURL object that I am using for creating and accessing important configuration file on iOS with features:
hidden from user
not user generated file (storing configuration related to user)
not temp or cache (not possible to create later with existing data)
must be backed up by iCloud/iTunes
[NSURL fileURLWithPath:[[NSSearchPathForDirectoriesInDomains(
NSLibraryDirectory,
NSUserDomainMask,
YES) objectAtIndex:0]
stringByAppendingString:#"/important.txt"]];
As suggested in FileSystemOverview (developer.apple.com), I am storing this file under Library.
Maybe better way is storing it under Library/Application Support.
Using NSSearchPathForDirectoriesInDomains, which takes:
enum NSSearchPathDirectory
NSApplicationDirectory
NSDeveloperApplicationDirectory
NSLibraryDirectory
NSDeveloperDirectory
NSApplicationSupportDirectory
...
enum NSSearchPathDomainMask
NSUserDomainMask
NSLocalDomainMask
NSSystemDomainMask
...
BOOL expandTilde
Is this the correct way of storing such a file?
There are couple of alternatives for NSSearchPathDirectory and NSSearchPathDomainMask.
Also what about the expandTilde, on iOS is it necessary?
Is there a better way of doing it, instead of creating path as a NSString using objectAtIndex and appending file name then converting it to NSURL?
Thanks.
Using NSApplicationSupportDirectory would be my first choice for this.
But keep a few things in mind:
Unlike the "Documents" folder, the "Library/Application Support" folder doesn't exist in an iOS app sandbox by default so you must create the folder before trying to use it.
"Hidden from the user" only means that the user won't see it under normal circumstances. But the file is easily accessible by anyone with any technical knowledge.
You do want to pass YES for the expandTilde parameter so your app returns a proper path when you run the app in the simulator. On a real iOS device, it makes little difference.
Do not use stringByAppendingString: to create paths. Use stringByAppendingPathComponent:.
NSString *appSupportPath = [NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES) firstObject];
NSString *filePath = [appSupportPath stringByAppendingPathComponent:#"important.txt"];
NSURL *fileURL = [NSURL fileURLWithPath:filePath];
You can get a direct NSURL using NSFileManager:
NSURL *appSupportURL = [[[NSFileManager defaultManager] URLsForDirectory:NSApplicationSupportDirectory inDomains:NSUserDomainMask] firstObject];
NSURL *fileURL = [appSupportURL URLByAppendingPathComponent:#"important.txt"];

ios 8: Bundle path changes

I have an iOS app that stores the absolute path of files in a database and in generated html documents. I just recently updated my iPhone to iOS 8 and now when ever I run the app it seems that the app is installed in a different directory every re-compile. For example on the first build/run [[NSBundle mainBundle] bundlePath] returns something different on the next build/run. What is going on? Is this a new feature of Apple?
Update: A bug report was created
Code example:
If I run the following line over multiple build/runs then I will get a different result each time.
#define kOLD_PATH #"oldPath"
NSString* newPath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) lastObject];
NSString* oldPath = [[NSUserDefaults standardUserDefaults] objectForKey:kOLD_PATH];
NSLog(#"New Path: %#", newPath);
NSLog(#"Old Path: %#", oldPath);
NSLog(#"Result: %#", [oldPath isEqualToString:newPath] ? #"Same" : #"Changed");
[[NSUserDefaults standardUserDefaults] setObject:newPath forKey:kOLD_PATH];
[[NSUserDefaults standardUserDefaults] synchronize];
The output looks like this over multiple runs
New Path: /var/mobile/Containers/Data/Application/4FFCE2CB-580D-409A-90CB-EF2B8A1FB653/Library
Old Path: /var/mobile/Containers/Data/Application/B038B2DA-F85D-4E18-A5F1-8635834EC454/Library
Result: Changed
Full Disclosure: In my app the user imports a web page (ePub) that has resources. The resources are stored with the web page. The web page also accesses resources that are part of the app bundle. To achieve this when I load the web page the base url is set to the directory the web page is in and the bundle resources are accessed via absolute file paths. Now that file paths change on every update this is broken. I tried creating symbolic links to the bundle resources but that also fails un subsequent updates.
In iOS 8, The file system layout of app containers has changed. Applications and their content are no longer stored in one root directory.
From the iOS 8 Release Notes:
The file system layout of app containers has changed on disk. Rather
than relying on hard-coded directory structure, use the
NSSearchPathForDirectoriesInDomains function or the
URLForDirectory:inDomain:appropriateForURL:create:error: method of the
NSFileManager class. See Accessing Files and Directories in File
System Programming Guide.
This is not a bug. Make sure you use the recommended APIs (from the above quote) and you won't have a problem.
So, If you are trying to access a bundled resource you added to the project, you would use:
[[NSBundle mainBundle] pathForResource:#"resourceName" ofType:#"extension"];
But if you want to use something that you put in the documents directory, you would use:
[[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject] stringByAppendingPathComponent:#"resourceName.extension"];
Refer Technical Note 2406 by Apple
The breaking change is
Beginning in iOS 8, the Documents and Library directories are no
longer siblings of your application's bundle.
Don't store full path/URL to your documents. Store the file name and always generate full path/URL with recommended approach.
Get the DocumentsDirectory URL
// Returns the URL to the application's Documents directory.
- (NSURL *)applicationDocumentsDirectory {
{
return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}
Then you get path out of url and append the file name to generate full path.
don't know if you solved your problem, but this link is possible the answer.
https://developer.apple.com/library/prerelease/ios/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/AccessingFilesandDirectories/AccessingFilesandDirectories.html#//apple_ref/doc/uid/TP40010672-CH3-SW10
Locating Files Using Bookmarks
A few lines before this section in the page is this text:
"Important: Although they are safe to use while your app is running, file reference URLs are not safe to store and reuse between launches of your app because a file’s ID may change if the system is rebooted. If you want to store the location of a file persistently between launches of your app, create a bookmark as described in Locating Files Using Bookmarks."
Good bye.
I think the different path for each build and run is the intended way of things happening in iOS simulator. It is not an issue.
/var/mobile/Containers/Data/Application/4FFCE2CB-580D-409A-90CB-EF2B8A1FB653/Library
/var/mobile/Containers/Data/Application/B038B2DA-F85D-4E18-A5F1-8635834EC454/Library
I found even if you use the recommended way
- (NSURL *)applicationDocumentsDirectory
{
return [[[NSFileManager defaultManager] URLsForDirectory:NSLibraryDirectory inDomains:NSUserDomainMask] lastObject];
}
The results are same. Different path for each build & run.

Default files in iOS application sandbox

I am creating a quiz app for iPhone. I store all the questions in an NSArray that is loaded from a .xml file every time the app is opened. That file will be the same accross all "instances" of the app, and it will never be changed by the user.
I could hard-code all the questions with code, but I found it more elegant to have it in a file that is easily edited by any text editor.
But how do I give each app "instance" of the app a copy of that file? That file should be bundled along with the rest of the application files.
This is the code I use so far (in app delegate).
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask,
YES);
NSString *path = documentPaths[0];
path = [path stringByAppendingPathComponent:#"questions.archive"];
NSArray *fileQuestions = [[NSArray alloc] initWithContentsOfFile:path];
if (!fileQuestions)
{
// Code to add three default questions…
[fileQuestions writeToFile:path
atomically:YES];
}
// And here the "file questions" are transformed to instances of my question class
No need to try to store the file in Documents directory. Just store it right there in the app bundle itself. This works exactly like an image file, a sound file, or any other resource. Make the file part of the project; make sure it is part of the app target, so that it will be copied into the app bundle as part of the build process. In the running app, get its path with [[NSBundle mainBundle] pathForResource:ofType:], and read it as you would any file of this type.

Does an iOS app have write access inside its bundle?

I save some run-time generated files inside the .app bundle of my iOS app. In the simulator it works fine, in the device it crashes:
Could create output files in the given shader cache path
'/var/mobile/Applications/CB064997-B40E-4FE3-9834-B3217CE33489/SimedTest.app/Ogre3D/assets/RTShaderLib/cache/
Is there a good overview of where I should and shouldn't put files - how to use Documents, Library and tmp, etc?
To clarify, these are files created at startup which pre-calculate some data to save time. IF they are not present they get created so it's fine they are deleted, but not while the app is running.
The bundle is read-only. You don't want to mess around with it for two reasons:
Code Signing: the signature is verified by against the contents of the bundle; if you mess around with the bundle, you break the signature.
App Updates: updates work by replacing the entire app bundle with a newly downloaded one; any changes you make will get lost.
Where you should save stuff:
Documents: if you want it to persist and be backed up
Library/Caches: if you just want to cache downloaded data, like profile pics; will be auto deleted by the system if it is low on room unless you specify with a special do-not-delete flag.
tmp: temporary files, deleted when your app is not running
For a full explanation check out File System Programming Guide and QA1719.
No, every time you change your bundle you invalidate your signature.
If you want to write files you`l need to write in the best folder depending on what you want to do with that file.
Documents folder for long duration files
Cache for small operations
and so on
EDIT
To get the path you`ll need something like this:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:#"filename.ext"];
With this path you can write or read like this:
write:
NSString *content = #"One\nTwo\nThree\nFour\nFive";
[content writeToFile:fileName atomically:NO encoding:NSStringEncodingConversionAllowLossy error:nil];
read:
NSString *content = [[NSString alloc] initWithContentsOfFile:fileName usedEncoding:nil error:nil];

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