I am adding .txt file to Documents folder for storing some data using solution founded here:
Read Text File in Document Folder - Iphone SDK
So now I can write and read text from this file succesfully, but I need also to have action what will clear all text in this file to make it absolutely empty. Is it possible?
In one line, this ought to do it:
[[NSData data] writeToFile: pathToFile atomically: YES];
This will loop all files -in Documents Directory- which has suffix of "txt" and delete its contents:
NSString* path = [NSHomeDirectory() stringByAppendingPathComponent:#"Documents"];
NSArray *arr = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:path error:nil];
for (NSString *fileName in arr) {
if ([fileName hasSuffix:#".txt"])
{
[#"" writeToFile:[path stringByAppendingPathComponent:fileName] atomically:YES encoding:NSUTF8StringEncoding error:nil];
}
}
Related
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
}
I'm working on “Folders feature” in my player app, but I have something confused with file recursive. I want to recursive the Document Files then save the folder and files used Dictionary&Array.
Here is my code:
- (void)fileRecursive:(NSString *)path{
BOOL isDir;
[_fm fileExistsAtPath:path isDirectory:&isDir];
if (isDir) {
//Folder
NSString *folderName = [path lastPathComponent];
[self.folderArray addObject:folderName];
NSLog(#"Folder %#",folderName);
NSArray *files = [_fm contentsOfDirectoryAtPath:path error:nil];
for (NSString *file in files) {
[self fileRecursive:[path stringByAppendingPathComponent:file]];
}
}else{
//File
NSString *fileName = path;
[self.fileArray addObject:fileName];
NSLog(#"File %#",fileName);
}
}
After recursive, I would like to get a Dictionary like this:
dic{
"Folder1":[file1,file2];
"Folder2":[file3,file4];
"RootFolder":[file0];
}
What code I need to add? Thanks.
I have solved the problem last days, It's weird to use recursion. So just traverse the directory, and record the files and folders, if open the folder, then do that again.
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 have created save.plist in a resource folder. I have written some data within that directly (without using coding). I am able to read that data but I'm not able to write through code to the same save.plist. By using following code I am trying to write the data but it gets stored within my .app plist.
The code is here
NSString *errorDesc = nil;
NSPropertyListFormat format;
NSString *plistPath = [[NSBundle mainBundle] pathForResource:#"save" ofType:#"plist"];
NSData *plistXML = [[NSFileManager defaultManager] contentsAtPath:plistPath];
NSMutableDictionary *temp = (NSMutableDictionary *)[NSPropertyListSerialization
propertyListFromData:plistXML
mutabilityOption:NSPropertyListMutableContainersAndLeaves
format:&format errorDescription:&errorDesc];
if (!temp) {
NSLog(errorDesc);
[errorDesc release];
}
// [temp setValue:#"123" forKey:#"line1"];
// [temp writeToFile:plistPath atomically: YES];
//Reading data from save.plist
NSLog([temp objectForKey:#"name"]);
NSLog([temp objectForKey:#"wish"]);
NSNumber *num=[temp valueForKey:#"roll"];
int i=[num intValue];
printf("%d",i);
//writitng the data in save.plist
[temp setValue:#"green" forKey:#"color"];
[temp writeToFile:plistPath atomically: NO];
NSMutableDictionary *temp1 = (NSMutableDictionary *)[NSPropertyListSerialization
propertyListFromData:plistXML
mutabilityOption:NSPropertyListMutableContainersAndLeaves
format:&format errorDescription:&errorDesc];
NSLog([temp objectForKey:#"color"]);
I want that, the data which I want to write should get written into save.plist only which is stored in references. I am new with this concept. So if anyone knows it please help me.
Thanks in advance.
:-)
I don't know if I understand your question, but if you want to write into a .plist within your .app bundle you are probably doing something wrong. If you want to store preferences, you should consider using NSUserDefaults.
If you really want to modify a bundled .plist - here is some code:
NSString *plistPath = nil;
NSFileManager *manager = [NSFileManager defaultManager];
if (plistPath = [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent:#"Contents/Info.plist"])
{
if ([manager isWritableFileAtPath:plistPath])
{
NSMutableDictionary *infoDict = [NSMutableDictionary dictionaryWithContentsOfFile:plistPath];
[infoDict setObject:[NSNumber numberWithBool:hidden] forKey:#"LSUIElement"];
[infoDict writeToFile:plistPath atomically:NO];
[manager changeFileAttributes:[NSDictionary dictionaryWithObject:[NSDate date] forKey:NSFileModificationDate] atPath: [[NSBundle mainBundle] bundlePath]];
}
}
Update:
Nate Flink pointed out that some of the NSFileManager methods used above are deprecated.
He posted an answer with the replacement methods below:
https://stackoverflow.com/a/12428472/100848
Updated version of the original awesome example by weichsel (thank you!). Xcode threw a couple warnings one of which is a deprecated method on NSFileManager. Updated here with non-deprecated methods from iOS 5.1
NSString *plistPath = nil;
NSFileManager *manager = [NSFileManager defaultManager];
if ((plistPath = [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent:#"mySpecial/PathTo.plist"]))
{
if ([manager isWritableFileAtPath:plistPath])
{
NSMutableDictionary *infoDict = [NSMutableDictionary dictionaryWithContentsOfFile:plistPath];
[infoDict setObject:#"foo object" forKey:#"fookey"];
[infoDict writeToFile:plistPath atomically:NO];
[manager setAttributes:[NSDictionary dictionaryWithObject:[NSDate date] forKey:NSFileModificationDate] ofItemAtPath:[[NSBundle mainBundle] bundlePath] error:nil];
}
}
When you build the app, it will create an executable file "appName.app" and all the files are built in the bundle. Therefore, you can't access to resource folder when the app is running because all the data is in the bundle(not in folder).
However, you can access to a temp folder which contains some information of the app.
You can find the temp folder here:
Open finder--click on your username(under PLACES)--Library--Application Support--iPhone Simulator--User--Applications--(here you can find all the temp folders of your iPhone apps)
You can access to this temp folder by:
NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
If you name your file save.plist, you can access to it like this:
NSString *filePath = [documentsDirectory stringByAppendingString:#"_save.plist"];
Then you just save your file to this filePath and it will appear in the temp folder named "Documents_save.plist".
*Note that the temp folder's name varies every time you run the app.
Recommend a book for you: 《Beginning iPhone Development--Exploring the iPhone SDK》. In Chapter 11 you can find what you want.
To summarize some of the other answers:
You're problem is that you're trying to write the file back into the folder that contains your application. That folder is not writable at runtime. Everything you're doing is fine, you just need to pick a different location to write your file to.
You can use the NSSearchPathForDirectoriesInDomains function to find a more suitable folder for this data. (Such as the #"Documents" folder.)
try this:
-(void)add:(NSRunningApplication *) app {
if ([self contains:app]) return;
[self.apps addObject:app.localizedName];
[self.apps writeToFile:self.dataFile atomically:YES];
}
from "Cocoa Programming".
you have to copy your plist into document directory...
because you cannot save anything without saving into document file....when you copied it will allow to write/modify on plist
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.