I am creating an application. I am storing the files in Document directory. And after my work completed, delete the files from document directory as like below:
NSMutableDictionary * Dictionary = [NSMutableDictionary alloc]init];
// Next every file storing into this dictionary like below
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *baseDir = [paths objectAtIndex:0];
NSString *pathComp = [baseDir stringByAppendingPathComponent:[NSString stringWithFormat:#"IMG%d.PNG",presentCount];
fileURL = [NSURL fileURLWithPath:pathComp];
[Dictionary setObject:fileURL forKey:fileURL];
while ([[Dictionary allKeys]count]!=0) {
NSURL *deleteFileURL = [[Dictionary allKeys] lastObject];
NSLog(#"Path %#",deleteFileURL.path);
[[NSFileManager defaultManager] removeItemAtPath:deleteFileURL.path error:nil];
[Dictionary removeObjectForKey:deleteFileURL];
}
Here my problem is, after delete the files from document directory, memory is not reduced, still it's occupying as like files exist. Due to this issue, my is crashing. So please help me how to clear the memory.
Actually i am getting the files(Photos ) from the server and first placing in documents directory,and trying to save using photo library.Once i give input from dictionary to photo library, after completion handler, i am trying to delete the file.Its removed and photo saved, but memory is not reduced.
1、Remove the file after checking for the existence of a file on the path, and check the return value of removeItemAtPath: to determine if the deletion succeeded.
NSString *path = #"a/b";
if ([[NSFileManager defaultManager] fileExistsAtPath:path]) {
BOOL success = [[NSFileManager defaultManager] removeItemAtPath:path error:nil];
// Check the success's value
}
Related
I have created a custom property list file. The file is stored in the application document.
While user login is successful the login information is stored in the plist, and it is working fine.
The plist content are cleared while log out, this also works fine.
When i am still login i killed the application. When the app opens the plist data i cleared.
code used to save to file:
NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];
NSString *plistPath = [documentsPath stringByAppendingPathComponent:#"xxxxPlist.plist"];
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath])
{
plistPath = [[NSBundle mainBundle] pathForResource:#"xxxxPlist" ofType:#"plist"];
}
dict=[[self cleanDictionary:[dict mutableCopy]] mutableCopy];
NSDictionary *plistDict=[[NSDictionary alloc] initWithObjectsAndKeys:dict,#"login_data", nil];
NSError *error = nil;
NSData *plistData = [NSPropertyListSerialization dataWithPropertyList:plistDict format:NSPropertyListXMLFormat_v1_0 options:NSPropertyListImmutable error:&error];
if(plistData)
{
[plistData writeToFile:plistPath atomically:YES];
}
else
{
//error here
NSLog(#"%# ",error);
}
code used to fetch data
NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];
NSString *plistPath = [documentsPath stringByAppendingPathComponent:#"xxxx.plist"];
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath])
{
plistPath = [[NSBundle mainBundle] pathForResource:#"xxxxPlist" ofType:#"plist"];
}
NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:plistPath];
return [dict objectForKey:#"login_data"];
I there any way out to persist the data?
There are several things that may be causing problems
When saving to file
1) My understanding is that you specifically want to save to /Documents folder specifically to ensure your file persists
2) So you correctly build following path
"/Documents/xxxxPlist.plist"
3) But then why do you check if a file already exists at that location?
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath])
{
plistPath = [[NSBundle mainBundle] pathForResource:#"xxxxPlist" ofType:#"plist"];
}
You just have to write to the path when you are ready.
If there is an old file at this location it will be overwritten.
And my understanding is this is the wanted behaviour, because you've already read that file and the data is in that dictionary "dict".
4) Also, by asking NSBundle to give you path for your file name
"xxxxPlist.plist"
there is a risk that it will just give you back some other path with file named the same (not in /Documents) if such file happens to exist. For example if you happened to write to say, /Cache folder earlier (with different code), your app will keep getting the /Cache path and keep reading/writong there (not in /Documents). And with the existing code you would have gotten nil here for path on the very first run, so not sure how he file got created in the first place.
5) Then I am not sure what exactly does this line
dict=[[self cleanDictionary:[dict mutableCopy]] mutableCopy];
Why first make a mutable copy, then presumably get immutable copy back and get a mutable one of it. Can't -cleanDictionary: just return the same mutable copy it was passed?
When reading from file
1) Not sure why you're searching for a different file first?
"/Documents/xxxx.plist" not "/Documents/xxxxPlist.plist"
Also what happens if "xxxx.plist" exists, then you'll never get to "xxxxPlist.plist" that you are writing in the other section.
2) Then, yes, you have to check if a file exists at certain path before you try to read it. But, in your case, if it does not exist, you don't ask NSBundle for another location, because you need your specific file in /Documents, and you don't know what you'll get from NSBundle, if your file is not where it should be.
So if there is no "xxxxPlist.plist" file, it's just your first run of the app and you will be creating your initial dict.
I have a folder called PhotoSet in my Xcode iOS App. I want to convert the UIImage to a jpg and put it into the folder. Here is what I have so far (by the way, if it is at all relevant, the UIImage is taken from a photo that the user takes):
NSData * imageData = UIImageJPEGRepresentation(chosenImage, 1.0);
if (imageData != nil) {
[imageData writeToFile:#"/Users/Toly/Desktop/PhotoMap/PhotoMap/PhotoSet/test.jpg" atomically:YES];
}
I get no errors or warnings. However, no picture gets saved to any folder. What should I do?
You need to write to a directory that is actually on the iPhone. Most of the time you'll want to write to the documents directory. You can get the path to it like this:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
This gives you the base documents directory, if you want to place the folder in a sub directory you'll need to create that folder before you do like so.
NSString *folderPath = [documentsDirectory stringByAddingPathComponent:#"myFolder/images"];
NSError *error = nil;
NSFileManager *fm = [[NSFileManager alloc] init]
[fm createDirectoryAtPath:folderPath withIntermediateDirectories:YES attributes:nil error:&error];
Then to save your image data to that folder you'll do something like this
NSString *imageDataPath = [folderPath stringByAppendingPathComponent:#"myImage"];
BOOL success = [imageData writeToFile:imageDataPath];
Also, you can NSLog the imageDataPath it'll give you the exact location that file is saved so you can navigate to the actual file in finder if you're using the iOS simulator.
Your phone does not contain a data structure of files mirroring "/Users/Toly/Desktop/PhotoMap/PhotoMap/PhotoSet/test.jpg"
If you want the image to persist in memory, try using nsuserdefaults, or xcassets or Coredata. If you are absolutely intent on writing to a file, check out the NSCoding and NSFileManager tutorial below:
http://www.raywenderlich.com/1914/nscoding-tutorial-for-ios-how-to-save-your-app-data
I'm loading a file to a NSMutableArray. I'm doing it like this:
if(!self.dataArray){
self.dataArray = [[NSMutableArray alloc] init];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *arrayPath = [[paths objectAtIndex:0]
stringByAppendingPathComponent:#"array.out"];
self.dataArray = [NSMutableArray arrayWithContentsOfFile:arrayPath];
}
The array that is loaded into the file consists of multiple NSDictionaries.
However, this somehow deallocates the array in the memory because when I log dataArray after doing this, it logs nil. How come?
Update
I've figured out that [NSMutableArray arrayWithContentsOfFile:arrayPath] is logging nil because the code in which I'm uploading the content to the file, doesn't create the file:
// write data to disk
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *arrayPath = [[paths objectAtIndex:0]stringByAppendingPathComponent:#"array.out"];
[self.dataArray writeToFile:arrayPath atomically:YES];
NSLog(#"uploaded file: %#", arrayPath); // logs an arrayPath, but one that doesn't exists.
Check the following,
Check the dataArray is a weak property ? If so, change to strong.
Check the file exists at path, using
[[NSFileManager defaultManager] fileExistsAtPath:arrayPath];
Verify the file have expected content, by logging it.
Confirm the File content is organized as a property list (plist). Verify it in plist editor/Xcode.
If you dynamically creating it, check the path you are writing to.
Confirm the method of writing NSArray to plist. Use
[array writeToFile:path atomically:YES];
Note:
If you are dynamically creating the file and you are testing on Simulator; you can
find the file by logging file path and following it on Finder.
Property List Reference
Apple documentation
Per Apple documentation, the array returns nil if the file can’t be opened or if the contents of the file can’t be parsed into an array.
Did you use the [writeToFile:atomically:] method to write the array to a file?
Also, make sure that the filePath string matches exactly on both write and read ends. I've wasted a lot of time trying to hunt down a bug when it turned out I had misspelled the name of the file or used the wrong file extension.
Another possibility: have you confirmed that this code is being executed? Sometimes I've had to change (!self.someProperty) to (self.someProperty != nil) in my if condition to get code like this to run.
Peter Segerblom and wildBillMunson are right: the array returns nil if the file can't be opened or if its content can't be parsed into an array.
You said "array.out" is an array of NSDictionaries. Whenever I have that set of data, I use the plist type of file and read it this way:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES);
NSString *directory = [paths objectAtIndex:0];
NSString *fullPath = [directory stringByAppendingPathComponent:#"data.plist"];
NSString *errorDesc = nil;
NSPropertyListFormat format;
NSData *plistXML = [[NSFileManager defaultManager] contentsAtPath:fullPath];
NSArray *data = (NSArray *)[NSPropertyListSerialization propertyListFromData:plistXML mutabilityOption:NSPropertyListMutableContainersAndLeaves format:&format errorDescription:&errorDesc];
Be sure to check if fullPath is not returning nil.
Hope this helps!
Pulling my hair out trying to work this out. i want to read and write a list of numbers to a txt file within my project. however [string writeToFile:path atomically:YES encoding:NSUTF8StringEncoding error:&error] doesnt appear to write anything to the file. I can see there is the path string returns a file path so it seems to have found it, but just doesnt appear to write anything to the file.
+(void)WriteProductIdToWishList:(NSNumber*)productId {
for (NSString* s in [self GetProductsFromWishList]) {
if([s isEqualToString:[productId stringValue]]) {
//exists already
return;
}
}
NSString *string = [NSString stringWithFormat:#"%#:",productId]; // your string
NSString *path = [[NSBundle mainBundle] pathForResource:#"WishList" ofType:#"txt"];
NSError *error = nil;
[string writeToFile:path atomically:YES encoding:NSUTF8StringEncoding error:&error];
NSLog(#"%#", error.localizedFailureReason);
// path to your .txt file
// Open output file in append mode:
}
EDIT: path shows as /var/mobile/Applications/CFC1ECEC-2A3D-457D-8BDF-639B79B13429/newAR.app/WishList.txt so does exist. But reading it back with:
NSString *path = [[NSBundle mainBundle] pathForResource:#"WishList" ofType:#"txt"];
returns nothing but an empty string.
You're trying to write to a location that is inside your application bundle, which cannot be modified as the bundle is read-only. You need to find a location (in your application's sandbox) that is writeable, and then you'll get the behavior you expect when you call string:WriteToFile:.
Often an application will read a resource from the bundle the first time it's run, copy said file to a suitable location (try the documents folder or temporary folder), and then proceed to modify the file.
So, for example, something along these lines:
// Path for original file in bundle..
NSString *originalPath = [[NSBundle mainBundle] pathForResource:#"WishList" ofType:#"txt"];
NSURL *originalURL = [NSURL URLWithString:originalPath];
// Destination for file that is writeable
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSURL *documentsURL = [NSURL URLWithString:documentsDirectory];
NSString *fileNameComponent = [[originalPath pathComponents] lastObject];
NSURL *destinationURL = [documentsURL URLByAppendingPathComponent:fileNameComponent];
// Copy file to new location
NSError *anError;
[[NSFileManager defaultManager] copyItemAtURL:originalURL
toURL:destinationURL
error:&anError];
// Now you can write to the file....
NSString *string = [NSString stringWithFormat:#"%#:", yourString];
NSError *writeError = nil;
[string writeToFile:destinationURL atomically:YES encoding:NSUTF8StringEncoding error:&error];
NSLog(#"%#", writeError.localizedFailureReason);
Moving forward (assuming you want to continue to modify the file over time), you'll need to evaluate if the file already exists in the user's document folder, making sure to only copy the file from the bundle when required (otherwise you'll overwrite your modified file with the original bundle copy every time).
To escape from all the hassle with writing to a file in a specific directory, use the NSUserDefaults class to store/retrieve a key-value pair. That way you'd still have hair when you're 64.
I need some help for a problem which I can't solve but I think I am close to the solution. Here is it:
In a version of my app, I was able to populate a tableview (in CellforRowAtIndexPath) with images taken from the Assetlibrary using the following 2 lines:
ALAsset someAsset = [theAssets objectAtIndex:indexPath.row];
[cell.imageView setImage:[UIImage imageWithCGImage:[someAsset thumbnail]]];
Now, I am trying to read image files from the directory and stored in an NSMutableArray. I can see the filenames when I NSLog the NSMutableArray. But how do I now cause the files to be converted into images and displayed in my tableview in the same way I did why using the Assetlibrary? I have tried several times, but the app either crashes or it does not show the image thumbnails in the table view. For example, this statement does not display the image but the app does not crash:
UIImage *anImage = [UIImage imageWithContentsOfFile:[self.listTable objectAtIndex:0]];
When I setImage in the next line, it doesn't work. Someone please help!
UPDATED: The contents of self.listable when I NSLog it is something like this: "19-10-25 276-10-12.jpg",
"19-10-37 276-10-12.jpg",
"19-10-54 276-10-12.jpg",
"19-10-65 276-10-12.mov", etc.
When I NSLog my documents directory, it is: /var/mobile/Applications/8CB1368A-AAE2-4815-BD26-A7B7C8536193/Documents.
Apps can only imageWithContentsOfFile for files located within the app's sandbox (e.g. in Documents, the bundle, etc.) If these files are located in your Documents folder, you get the full path via:
NSString *documentsFolder = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *imageFullPath = [documentsFolder stringByAppendingPathComponent:imageFilename];
You can then use that in imageWithContentsOfFile.
Update:
You asked:
my directoryContents is an NSArray; how do I convert it to NSString and then [documentsFolder stringByAppendingPathComponent ...] and store each fullpath in the NSMutableArray?
You might do something like:
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSArray *filenames = [fileManager contentsOfDirectoryAtPath:documentsDirectory error:nil];
NSMutableArray *paths = [[NSMutableArray alloc] initWithCapacity:[filenames count]];
for (NSString *filename in filenames)
{
[paths addObject:[documentsDirectory stringByAppendingPathComponent:filename]];
}
NSLog(#"%s filenames = %#", __FUNCTION__, filenames);
NSLog(#"%s paths = %#", __FUNCTION__, paths);