Empty documents directory after creating file with NSFileHandle - ios

I'm writing an application for the Apple watch. I'm using the following method (from this SE answer) to write to a log file:
- (void) writeLogWith: (NSString *) content {
//Get the file path
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *fileName = [documentsDirectory stringByAppendingPathComponent:#"whathappened.md"];
//create file if it doesn't exist
if(![[NSFileManager defaultManager] fileExistsAtPath:fileName])
[[NSFileManager defaultManager] createFileAtPath:fileName contents:nil attributes:nil];
//append text to file (you'll probably want to add a newline every write)
NSFileHandle *file = [NSFileHandle fileHandleForUpdatingAtPath:fileName];
[file seekToEndOfFile];
[file writeData:[content dataUsingEncoding:NSUTF8StringEncoding]];
[file closeFile];
return;
}
I'm running it by plugging in my phone and running it directly on my watch. The function is definitely executing (I've stepped thought with the debugger) and it also knows that the file exists and doesn't repeatedly try and create it.
Xcode tells me that the file information is:
Printing description of documentsDirectory:
/var/mobile/Containers/Data/PluginKitPlugin/8503AD6C-6EC9-4522-A867-27109B01B615/Documents
Printing description of documentsDirectory:
(NSString *) documentsDirectory = 0x16d66890
Printing description of fileName:
(NSString *) fileName = 0x16d66950
Printing description of fileName:
/var/mobile/Containers/Data/PluginKitPlugin/8503AD6C-6EC9-4522-A867-27109B01B615/Documents/whathappened.md
I'd like to know if it's writing things correctly, but when I look at the container (following these SE answers), the documents directory is empty.
My question is: where did my file go? And how can I find it?

I think what might be giving you problems is the NSFileHandle object. I have written thousands upon thousands of files to the documents folder and I have never used NSFileHandle to do this. Simply use the built in method on NSString to write your string to the file path.
Try this:
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *filePath = [[documentsDirectory stringByAppendingPathComponent:#"whathappened"] stringByAppendingPathExtension:#"md"];
if (![[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
[[NSFileManager defaultManager] createFileAtPath:filePath contents:nil attributes:nil];
}
NSString *string = #"The String You Want To Write.";
NSError *error;
[string writeToFile:filePath atomically:false encoding:NSUTF8StringEncoding error:&error];
if (error) {
NSLog(#"There was an error writing file\n%#", error.localizedDescription);
}
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
NSLog(#"File exists :)");
}
else {
NSLog(#"File does not exist :(");
}

From other research, the answer appears to be:
If you are storing a file on the Apple Watch, it is stored in it's own container, which isn't visible via xcode.
It indeed, appears to be related to this bug report: https://openradar.appspot.com/radar?id=5021353337946112, found via this SE: How to export shared container of an iOS App with Xcode6.2?

Related

how to use sqlite in iOS when i use iPhone to run the project

when i use simulator,i can find the database file in /documents .but when i use my iPhone to run the project,i can not find the database file.
what time should i create the database file or use this code in my project?
NSArray *searchPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentFolderPath = [searchPaths objectAtIndex:0];
NSString *dbFilePath = [documentFolderPath stringByAppendingString:DATABASENAME];
NSFileManager *fm = [NSFileManager defaultManager];
BOOL isExist = [fm fileExistsAtPath:dbFilePath];
if (!isExist) {
NSString *backupDbPath = [[[NSBundle mainBundle]resourcePath]stringByAppendingString:DATABASENAME];
[fm copyItemAtPath:backupDbPath toPath:dbFilePath error:nil];
}
For the first time or the database file does not exist in the documents directory, you have to copy DB file to document directory:
-(void)copyDatabaseIntoDocumentsDirectory{
// Check if the database file exists in the documents directory.
NSString *destinationPath = [self.documentsDirectory stringByAppendingPathComponent:self.databaseFilename];
if (![[NSFileManager defaultManager] fileExistsAtPath:destinationPath]) {
// The database file does not exist in the documents directory, so copy it from the main bundle now.
NSString *sourcePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:self.databaseFilename];
NSError *error;
[[NSFileManager defaultManager] copyItemAtPath:sourcePath toPath:destinationPath error:&error];
// Check if any error occurred during copying and display it.
if (error != nil) {
NSLog(#"%#", [error localizedDescription]);
}
}
}
Ref: http://www.appcoda.com/sqlite-database-ios-app-tutorial/
You can't access the directories of iPhone or iPad. So even if you successfully created a database, you won't see it. You can judge its existence by read data from it.

Saving CSV file to documents directory folder

I am writing a registration app that is supposed to save a CSV file in the documents directory folder. I would like to look at the output and see what happens when I open the CSV file in excel. I navigated to the documents directory folder by finding out where it should be saved using this code snippet:
NSLog(#"Info Saved");
NSLog(#"Documents Directory: %#", [[[NSFileManager defaultManager]
URLsForDirectory:NSDocumentDirectory
inDomains:NSUserDomainMask] lastObject]);
Here is my code for saving the information put into the 11 text fields in the registration form:
- (IBAction)saveFormButton:(id)sender {
// saves text field data in comma separated CSV file format
NSString *formData = [NSString stringWithFormat:#"%#,%#,%#,%#,%#,%#,%#,%#,%#,%#,%#\n",
self.nameTextfield.text, self.emailTextfield.text,
self.phoneTextfield.text, self.termTextfield.text,
self.schoolTextfield.text, self.graduationTextfield.text,
self.gpaTextfield.text, self.degreeTextfield.text,
self.interestTextfield.text, self.groupTextfield.text,
self.appliedTextfield.text];
// get document directory path
NSString *documentDirectoryPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES)objectAtIndex:0];
// append results.csv onto doc path
NSString *event = [documentDirectoryPath stringByAppendingString:#"results.csv"];
// creates folder if it does not exist
if (![[NSFileManager defaultManager] fileExistsAtPath:documentDirectoryPath]) {
[[NSFileManager defaultManager] createFileAtPath:event contents:nil attributes:nil];
}
NSFileHandle *fileHandle = [NSFileHandle fileHandleForUpdatingAtPath:event];
[fileHandle seekToEndOfFile];
[fileHandle writeData:[formData dataUsingEncoding:NSUTF8StringEncoding]];
[fileHandle closeFile];
Should I be seeing a file in that specific folder I have navigated to?
Thank you for your help,
Change this line:
NSString *event = [documentDirectoryPath stringByAppendingString:#"results.csv"];
to:
NSString *event = [documentDirectoryPath stringByAppendingPathComponent:#"results.csv"];
This makes sure that the path is correctly formatted. Also, you seem to be checking to see if "documentDirectoryPath" exists before creating the file rather than the filename itself. Change:
if (![[NSFileManager defaultManager] fileExistsAtPath:documentDirectoryPath]) {
[[NSFileManager defaultManager] createFileAtPath:event contents:nil attributes:nil];
}
to:
if (![[NSFileManager defaultManager] fileExistsAtPath:event]) {
[[NSFileManager defaultManager] createFileAtPath:event contents:nil attributes:nil];
}
Here is a more elegant way with less code
// Content of file
NSString* str= #"str,hey,so,good";
// Writing
NSString *root = [NSHomeDirectory() stringByAppendingPathComponent:#"file.csv"];
[str writeToFile:root atomically:YES encoding:NSUTF8StringEncoding error:NULL];
// Reading
NSString *string = [[NSString alloc] initWithContentsOfFile:root encoding:NSUTF8StringEncoding error:nil];
NSLog(#"%#",string);
The result:
2015-07-15 15:52:56.267 ObjC[2927:15828] str,hey,so,good

Writing a csv from app, Cocoa error 513

I am creating an iPhone app that writes to a CSV file. It seems the most simple method of this would be to add to an NSMutableString from an array. The code I have should be working expect I keep getting Cocoa error 513
The code is:
NSArray *firstArray=[NSArray arrayWithObjects:#"A",#"b",nil];
NSMutableString *csv = [NSMutableString stringWithString:#"Strings"];
NSUInteger count = [firstArray count];
for (NSUInteger i=0; i<count; i++ ) {
[csv appendFormat:#"\n %#",
[firstArray objectAtIndex:i]
];
}
NSString *yourFileName = #"leads.csv";
NSError *error;
BOOL res = [csv writeToFile:yourFileName atomically:YES encoding:NSUTF8StringEncoding error:&error];
if (!res) {
NSLog(#"Error %# while writing to file %#", [error localizedDescription], yourFileName );
}
Thank you so much!
It is most likely because you are writing to a file location that you do not have permission to write.
Cocoa error 513 translates to the error NSFileWriteNoPermissionError.
Typically, this occurs when someone tries to write to a file within the applications bundle. You cannot modify the contents of a compiled app's bundle folder. This is because the bundle is a signed, compiled application.
When you eventually distribute the app through the iTunes App Store, the application has a digital signature that validates the contents of the app. This signature is generated at compile time and once signed, Apple does not want anyone tampering with the contents.
Make sure you are writing to an appropriate location, like Documents, Temp and Cache using something like the following:
NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0]; // Get documents folder
NSString *dataPath = [documentsDirectory stringByAppendingPathComponent:#"subFolder"];
NSString *filePath = [dataPath stringByAppendingPathComponent:#"fileName.csv"];
if (![[NSFileManager defaultManager] fileExistsAtPath:dataPath])
{
[[NSFileManager defaultManager] createDirectoryAtPath:dataPath withIntermediateDirectories:NO attributes:nil error:&error]; //Create folder
}
BOOL res = [csv writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:&error];
if (!res) {
NSLog(#"Error %# while writing to file %#", [error localizedDescription], yourFileName );
}
These folders are only accessible to your app. No other app can access the contents of these folders. (Likewise, your app cannot access another app's folders.)

Can't download a file in ios

Here is my code to download a book
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSString *resourceDocPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle]resourcePath] stringByDeletingLastPathComponent] stringByAppendingPathComponent:#"Documents"]];
NSString *filePath= [resourceDocPath stringByAppendingPathComponent:_bookname];//in _bookname i am already getting the value ,say abcd.pdf
NSLog(#"The bookfilepath is %#",filePath);
NSLog(#"the lenght of recieved data is %d", _recievedData.length);//here i get the correct file size also
[_recievedData writeToFile:filePath atomically:YES];
NSFileManager *filemgr;
filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: filePath] == YES)
{
flag=1;
NSLog (#"File exists");
}
else
{
NSLog (#"File not found"); //always this happens in the log
}
}
No file exists at the filePath. Why?
The funny part is _recievedData.length is returning the correct file size.
Because you cannot write into the app bundle ([[NSBundle mainBundle] resourcePath]).
Write to the documents folder instead.
It appears that this code getting the resource path, stripping off the last path component and then adding Documents. That's not the right way to get to the Documents folder. Instead, use NSSearchPathForDirectoriesInDomains:
NSString *documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];
NSString *filePath = [documentsPath stringByAppendingPathComponent:_bookname];

Copy images from an app to Documents Directory and rewrite them after it

I have an app where I have a certain amount of .jpg pictures (roughly 300). They serve as something to start with, because they're actually located in the internet, but obviously it's more convenient for user not to download all of them at the first start of the App, but to have them pre-packed.
I am required to rewrite these images everytime I get new information from server. Obviously, I can't touch the app bundle, so I see my steps like this:
Unpack the images from bundle to the Documents Directory at the first start of an App.
Access them only from Documents Directory, but not from bundle.
If it's necessary, I should rewrite them.
And thus my code will be unified, cause I will always use the same path to get the image.
The problem is that I know very little about the whole file system thing in iOS, so I don't know how to unpack the particular bundle contents to Documents Directory and also I don't know how to write to Documents Directory either.
Could you please help me with some code and also confirm that my solution scheme is right?
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *destPath = [documentsDirectory stringByAppendingPathComponent:#"images"]; //optionally create a subdirectory
//"source" is a physical folder in your app bundle. Once that has a blue color folder (not the yellow group folder)
// To create a physical folder in your app bundle: drag a folder from Mac's Finder to the Xcode project, when prompts
// for "Choose options for adding these files" make certain that "Create folder references for …" is selected.
// Store all your 300 or so images into this physical folder.
NSString *sourcePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"source"];
NSError *error;
[[NSFileManager defaultManager] copyItemAtPath:sourcePath toPath:destPath error:&error];
if (error)
NSLog(#"copying error: %#", error);
Edited per additional comment from the OP:
To rewrite with the same file name to the same directory, you can use a combination of fileExistsAtPath and removeItemAtPath to detect and remove the existing file before writing.
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath])
{
[[NSFileManager defaultManager] removeItemAtPath:filePath error:&error];
}
// now proceed to write-rewrite
Try this code
-(void)demoImages
{
//-- Main bundle directory
NSString *mainBundle = [[NSBundle mainBundle] resourcePath];
NSFileManager *fm = [NSFileManager defaultManager];
NSError *error = [[NSError alloc] init];
NSArray *mainBundleDirectory = [fm contentsOfDirectoryAtPath:mainBundle error:&error];
NSMutableArray *images = [[NSMutableArray alloc]init];
for (NSString *pngFiles in mainBundleDirectory)
{
if ([pngFiles hasSuffix:#".png"])
{
[images addObject:pngFiles];
}
}
NSLog(#"\n\n Doc images %#",images);
//-- Document directory
NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentDirectory = [paths objectAtIndex:0];
NSFileManager *fileManager = [NSFileManager defaultManager];
//-- Copy files form main bundle to document directory
for (int i=0; i<[images count]; i++)
{
NSString *toPath = [NSString stringWithFormat:#"%#/%#",documentDirectory,[images objectAtIndex:i]];
[fileManager copyItemAtPath:[NSString stringWithFormat:#"%#/%#",mainBundle,[images objectAtIndex:i]] toPath:toPath error:NULL];
NSLog(#"\n Saved %#",fileManager);
}
}

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