I´m writing certain values to a file. See Write Operations below.
This works fine when using iPad 6.1 Simulator.
When trying the same thing on my iPad it fails. I think it´s something with sandboxing. I haven´t found out yet which path is best on iOS Devices to write stuff for internal use.
Any ideas?
#pragma mark Write Operations to Tmp Folder
- (BOOL) psWriteFileWithName: (NSString*) fileName
withString:(NSString*) string {
NSString *fileName = #"artistNumber";
NSError * error = NULL;
NSString *filePath = [NSString stringWithFormat:#"/tmp/%#.txt",fileName];
[string writeToFile:filePath
atomically:YES
encoding: NSUTF8StringEncoding
error:&error];
return YES;
}
You cannot write to /tmp since this is outside of your app sandbox.
However your app also has a temp directory, which can be referenced with the NSTemporaryDirectory() function:
Which works like:
NSString *tempfilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:filename];
Here is you method with the correct NSTemporaryDirectory() implementation, also edit some error handling:
#pragma mark Write Operations to Tmp Folder
- (BOOL) psWriteFileWithName: (NSString*) fileName
withString:(NSString*) string {
NSString *fileName = #"artistNumber";
NSError *error = nil;
NSString *filePath = [NSTemporaryDirectory() stringByAppendingPathComponent:filename];
if (![string writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:&error] ) {
NSLog(#"Error writing file: %#", error);
return NO;
}
return YES;
}
Related
I am developing a zip extractor app i followed the algorithm that CRD explained #Here but i stuck at third step i am unable to rename the unzipped file which is at temporary directorary.
here is my code
NSURL *tempDir = [NSURL fileURLWithPath:destinationPath];
NSError *error;
NSURL *tmpDirectory = [[NSFileManager defaultManager] URLForDirectory:NSCachesDirectory inDomain:NSUserDomainMask appropriateForURL:tempDir create:YES error:&error];
if (error) {
return ;
}
tmpDirectory = [tmpDirectory URLByAppendingPathComponent:#"extracts"];
NSLog(#"temp dir %#",tmpDirectory);
NSLog(#"temp path %#",tmpDirectory.path);
[SSZipArchive unzipFileAtPath:zipFilePath toDestination:tmpDirectory.path];
NSArray *dirFiles = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:tmpDirectory.path error:nil];
NSLog(#"dir file %#",dirFiles);
for (NSString *string in dirFiles) {
NSArray *dirDestinationFiles = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:destinationPath error:nil];
NSLog(#"dir destination file %#",dirDestinationFiles);
[dirDestinationFiles enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
NSFileManager *fm = [NSFileManager defaultManager];
NSError *error;
if ([string isEqualToString:obj]) {
NSLog(#"Already present");
BOOL isMoved = [fm moveItemAtPath:tmpDirectory.path toPath:[destinationPath stringByAppendingString:[NSString stringWithFormat:#"/%#-1",string]] error:&error];
if (isMoved) {
NSLog(#"Moved");
}else{
NSLog(#"errorL %#", error);
NSLog(#"Not moved");
}
[fm removeItemAtPath:tmpDirectory.path error:&error];
[self moveFileToTrash:zipFilePath];
[self openExtractedFolderWithZipPath:zipFilePath toDestinationPath:destinationPath];
}
}];
}
Any Suggestions..
Thanks in Advance !
Let's just review your code to hopefully help you on your way.
It may seem minor, but pick good variable names:
NSURL *tempDir = [NSURL fileURLWithPath:destinationPath];
NSURL *tmpDirectory = [[NSFileManager defaultManager] URLForDirectory:NSCachesDirectory inDomain:NSUserDomainMask appropriateForURL:tempDir create:YES error:&error];
Two names which are semantically similar for different things, that is just confusing. How about, say, destinationURL instead of tempDir?
Next, when constructing/pulling apart/etc. pathnames or URLs you will be better off being consistent. Both NSURL and NSString provide similar methods for these operations, in one place you use them:
tmpDirectory = [tmpDirectory URLByAppendingPathComponent:#"extracts"];
but then restort to direct string manipulation using a path separator which may, or may not, be correct:
[destinationPath stringByAppendingString:[NSString stringWithFormat:#"/%#-1",string]]
The routines provided by NSURL and NSString abstract away from the details of path separators and how to, say, find the extension on the last path component (which you might find useful when renaming to avoid clashes).
Going back to:
tmpDirectory = [tmpDirectory URLByAppendingPathComponent:#"extracts"];
There is no reason for you to do this. The temporary directory is created for you and you should delete it after using it. So there is no need to create a subdirectory extracts within it, and by reassigning to the same variable you've lost the URL you need to delete the temporary directory.
Now something less obvious, in my comment above I wrote:
To move each item you must handle name clashes, to do this try the move and if you get an error indicating a name clash modify the destination name however you like and re-try the move, repeating until you succeed or you until reach some limit of tries (determined by you).
I didn't explain why you should do it this way and you have tackled the problem a different way: for each item you are going to move you check for names clashes before attempting the move by iterating over the names in the destination directory.
If you read Apple's documentation on the file system you will find they often recommend you try an operation and then examine any error returned instead of trying to predict whether an error will occur and avoid it. The reason for this is the file system is dynamic, other processes can be modifying it, so if you try to avoid an error you may still get one. In pseudocode you are better of doing something like:
moveDone = false
attemptCount = 0
while not moveDone and attemptCount < MAX_ATTEMPTS
move object
if object exists error
modify destination URL
increment attemptCount
else
moveDone = true
end
end
if not moveDone then handle error
Following this outline and using a simple count and the NSString/NSURL path routines will produce you a much simpler and more reliable solution than the one you have now posted as an answer.
HTH
Here is the code working for me.
NSURL *tempDir = [NSURL fileURLWithPath:destinationPath];
NSError *error;
NSURL *tmpDirectory = [[NSFileManager defaultManager] URLForDirectory:NSCachesDirectory inDomain:NSUserDomainMask appropriateForURL:tempDir create:YES error:&error];
if (error) {
return ;
}
tmpDirectory = [tmpDirectory URLByAppendingPathComponent:#"extracts"];
NSLog(#"temp dir %#",tmpDirectory);
NSLog(#"temp path %#",tmpDirectory.path);
[SSZipArchive unzipFileAtPath:zipFilePath toDestination:tmpDirectory.path];
NSArray *dirFiles = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:tmpDirectory.path error:nil];
NSLog(#"dir file %#",dirFiles);
for (NSString *string in dirFiles) {
NSArray *dirDestinationFiles = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:destinationPath error:nil];
NSLog(#"dir destination file %#",dirDestinationFiles);
NSMutableArray *folderCount = [[NSMutableArray alloc] init];
NSMutableArray *folderNumCount = [[NSMutableArray alloc] init];
[dirDestinationFiles enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
if ([obj containsString:string]){
[folderNumCount addObject:obj];
}
if ([string isEqualToString:obj]) {
[folderCount addObject:string];
}
}];
NSFileManager *fm = [NSFileManager defaultManager];
NSError *error;
if (folderCount.count == 0) {
NSLog(#"First time extract");
BOOL isMoved = [fm moveItemAtPath:tmpDirectory.path toPath:[destinationPath stringByAppendingString:[NSString stringWithFormat:#"/%#",string]] error:&error];
if (isMoved) {
NSLog(#"Moved");
}else{
NSLog(#"errorL %#", error);
NSLog(#"Not moved");
}
[fm removeItemAtPath:tmpDirectory.path error:&error];
// [self moveFileToTrash:zipFilePath];
// [self openExtractedFolderWithZipPath:zipFilePath toDestinationPath:destinationPath];
}else if (folderCount.count > 0){
NSLog(#"Already present");
BOOL isMoved = [fm moveItemAtPath:tmpDirectory.path toPath:[destinationPath stringByAppendingString:[NSString stringWithFormat:#"/%#-%lu",string,folderNumCount.count-1]] error:&error];
if (isMoved) {
NSLog(#"Moved");
}else{
NSLog(#"errorL %#", error);
NSLog(#"Not moved");
}
[fm removeItemAtPath:tmpDirectory.path error:&error];
// [self moveFileToTrash:zipFilePath];
// [self openExtractedFolderWithZipPath:zipFilePath toDestinationPath:destinationPath];
}
}
I am using this code below to copy a file selected in the file browser and copying it to the temp directory with a different name. But when I select a file with spaces in it, the program throws an error saying it cannot find the specified fine path. I have tried using escape methods but they do not work either. Are there any other ways to handle file names with spaces?
Code starts here:
[openPanel beginSheetModalForWindow:self.window completionHandler:^(NSInteger result) {
[openPanel close];
if (result == NSFileHandlingPanelOKButton) {
myString = [self randomStringWithLength:7];
NSString *filePath = [[[openPanel URLs] objectAtIndex:0] absoluteString];
NSLog(#"%#", filePath);
NSString *strTemp = [self extractString:filePath toLookFor:#"//" skipForwardX:2 toStopBefore:#".png"];
NSLog(#"%#",strTemp);
NSString *realThing = [strTemp stringByReplacingOccurrencesOfString:#"%20" withString:#"\\ "];
//strTemp = [strTemp stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(#"%#", realThing);
NSString* fullPath = [NSString stringWithFormat:#"/tmp/%#.png", myString];
NSLog(fullPath);
NSError *error = nil;
[[NSFileManager defaultManager] copyItemAtPath:realThing toPath:fullPath error:&error];
if(error) {
NSLog(#"Error!!!");
NSLog(#" error => %# ",error);
}
else {
NSLog(#"Saved to temp directory");
}
Anyone have experience with this? Thanks
Your conversion of the URL to a path is much too complicated and error-prone.
Just use the path method:
NSString *filePath = [[[openPanel URLs] objectAtIndex:0] path];
Alternatively, use copyItemAtURL:... instead of copyItemAtPath:....
You also should check the return value of copyItemAtPath:... as the indicator
of a failure:
if (![[NSFileManager defaultManager] copyItemAtPath:filePath toPath:fullPath error:&error]) {
NSLog(#" error => %# ",error);
}
Compare Handling Error Objects Returned From Methods:
Important: Success or failure is indicated by the return value of the
method. Although Cocoa methods that indirectly return error objects in
the Cocoa error domain are guaranteed to return such objects if the
method indicates failure by directly returning nil or NO, you should
always check that the return value is nil or NO before attempting to
do anything with the NSError object.
You seem to be trying to convert URLs to file paths by hand. Use fileSystemRepresentation instead.
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.
I've only been leaning Cocoa/Objective C for a few days so apologies that this is probably simple/obvious but it's got me stumped.
I've written this handler for saving 3 floats to a text file. However when I'm running it the files are not being saved. Could anyone suggest if there's an error in my code or if you think there's something else (like file write permissions) preventing the file from being written.
Research has lead me to look into Sandboxing, but that gets confusing very quickly and I'm hoping just running the app from xcode in debug would let me write to my user directory.
Heres the code:
- (IBAction)saveResultsAction:(id)sender {
//Sets up the data to save
NSString *saveLens = [NSString stringWithFormat:#"Screen width is %.02f \n Screen Height is %.02f \n Lens is %.02f:1",
self.myLens.screenWidth,
self.myLens.screenHeight,
self.myLens.lensRatio];
NSSavePanel *save = [NSSavePanel savePanel];
long int result = [save runModal];
if (result == NSOKButton) {
NSURL *selectedFile = [save URL];
NSLog(#"Save URL is %#", selectedFile);
NSString *fileName = [[NSString alloc] initWithFormat:#"%#.txt", selectedFile];
NSLog(#"Appended URL is %#", fileName);
[saveLens writeToFile:fileName
atomically:YES
encoding:NSUTF8StringEncoding
error:nil];
}
}
a NSURL object is no POSIX path..
its a URL and getting its description doesnt make it a path
NSString *fileName = [selectedFile.path stringByAppendingPathExtension:#"txt"];
BUT as said, you shouldnt have to append the .txt at all. just use what the panel returns. Else, there would be sandboxd errors because you dont have access rights to the modified filename :)
NSString *fileName = selectedFile.path;
The problem is that you don't need to append the file extension to the URL.The extension is already there.You could directly do this:
if (result == NSOKButton)
{
[saveLens writeToURL: [save URL]
atomically:YES
encoding:NSUTF8StringEncoding
error:nil];
}
I see you've already accepted an answer, but it may also be helpful to know how to debug this type of issue using NSError pointers.
Cocoa uses NSError with method calls which generate error conditions, which richly encapsulate errors. (Objective-C also has exceptions, but they're reserved for cases of programmer error, like an array index out of bounds, or a nil parameter that should never be.)
When you have a method which accepts an error pointer, usually it also return a BOOL indicating overall success or failure. Here's how to get more information:
NSError *error = nil;
if (![saveLens writeToFile:fileName
atomically:YES
encoding:NSUTF8StringEncoding
error:&error]) {
NSLog(#"error: %#", error);
}
Or even:
NSError *error = nil;
if (![saveLens writeToFile:fileName
atomically:YES
encoding:NSUTF8StringEncoding
error:&error]) {
[NSApp presentError:error];
}
I have been trying to create a new file inside of my application support folder while using NSApplicationSupportDirectory; I can write a file to it, but I have been unable to create a folder inside of Application Support.
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSApplicationSupportDirectory, NSUserDomainMask, YES);
NSString *applicationDirectory = [paths objectAtIndex:0];
//make a file name to write the data to using the application support: (attempting to create the blasted directory inside of application support directory
NSString *fileName = [NSString stringWithFormat:#"%#/managersemail.txt",
applicationDirectory];
//create content - formats with the managersemail.txt location
NSString* content = [NSString stringWithFormat:#"%#",[nameField stringValue]];
//save content to the documents directory
[content writeToFile:fileName
atomically:NO
encoding:NSStringEncodingConversionAllowLossy
error:nil];
NSDictionary* errorDict;
The code that I have listed above works great, except for the part about creating the folder in which I want to place the managersemail.txt. I tried to mimic the stringWithFormat that is listed in the NSString* content and then varying several ways however to no avail! Any thoughts?
NSAppleEventDescriptor* returnDescriptor = NULL;
Perhaps the solution provided on Cocoa with Love might be useful?
Excerpt:
- (NSString *)findOrCreateDirectory:(NSSearchPathDirectory)searchPathDirectory
inDomain:(NSSearchPathDomainMask)domainMask
appendPathComponent:(NSString *)appendComponent
error:(NSError **)errorOut
{
// Search for the path
NSArray* paths = NSSearchPathForDirectoriesInDomains(
searchPathDirectory,
domainMask,
YES);
if ([paths count] == 0)
{
// *** creation and return of error object omitted for space
return nil;
}
// Normally only need the first path
NSString *resolvedPath = [paths objectAtIndex:0];
if (appendComponent)
{
resolvedPath = [resolvedPath
stringByAppendingPathComponent:appendComponent];
}
// Check if the path exists
BOOL exists;
BOOL isDirectory;
exists = [self
fileExistsAtPath:resolvedPath
isDirectory:&isDirectory];
if (!exists || !isDirectory)
{
if (exists)
{
// *** creation and return of error object omitted for space
return nil;
}
// Create the path if it doesn't exist
NSError *error;
BOOL success = [self
createDirectoryAtPath:resolvedPath
withIntermediateDirectories:YES
attributes:nil
error:&error];
if (!success)
{
if (errorOut)
{
*errorOut = error;
}
return nil;
}
}
if (errorOut)
{
*errorOut = nil;
}
return resolvedPath;
}
Maybe you can try using the NSFileManager to create the folder, then write the file into the folder.
NSFileManager *fileManager = [NSFileManager defaultManager];
NSString *applicationSupport = [[NSString stringWithString:#"~/Library/Application Support/'YOUR APP'] stringByExpandingTildeInPath];
if ([fileManager fileExistsAtPath:applicationSupport] == NO)
[fileManager createDirectoryAtPath:applicationSupport withIntermediateDirectories:YES attributes:nil error:nil];
NSString *fileName = [NSString stringWithFormat:#"%#/managersemail.txt", applicationSupport];
NSString* content = [NSString stringWithFormat:#"%#",[nameField stringValue]];
//save content to the documents directory
[content writeToFile:fileName
atomically:NO
encoding:NSStringEncodingConversionAllowLossy
error:nil];
So something like that should work. Feel free to leave comments to ask questions.