When i try this code:
if ([[NSFileManager defaultManager] fileExistsAtPath:#"~/Library/Application Support/Staying Afloat/stats/static-stats.plist"] == NO) {
NSMutableDictionary* tempDict = [[NSMutableDictionary alloc]initWithObjectsAndKeys:
[[NSString alloc] initWithString:#"0"],#"completedGames",
[[NSString alloc] initWithString:#"0"],#"floatsCollected",
[[NSString alloc] initWithString:#"0"],#"sec",
[[NSString alloc] initWithString:#"0"],#"subScore",
[[NSString alloc] initWithString:#"0"],#"highScore",
[[NSString alloc] initWithString:#"0"],#"longestSec", nil];
[tempDict writeToFile:#"~/Library/Application Support/Staying Afloat/stats/static-stats.plist" atomically:YES];
NSLog(#"written file");
}
and this outputs with
2012-04-14 19:15:10.009 Staying Afloat[3227:9c07] written file
so the loop has run, but the file isn't written?
can anyone point my in the right dirrection for saving plists to non-localized places?
EDIT: this is for mac
You need to expand your path using -(NSString *)stringByExpandingTildeInPath when you write and check if the file exist.
Edit: Read the method writeToFile:automatically in the NSDictionary documentation. It says
If path contains a tilde (~) character, you must expand it with stringByExpandingTildeInPath before invoking this method.
So just do something like
[tempDict writeToFile:[[NSString stringWithString:#"~/Library/Application Support/Staying Afloat/stats/static-stats.plist"] stringByExpandingTildeInPath] atomically:YES];
first you can't just write :
[tempDict writeToFile:#"~/Library/Application Support/Staying Afloat/stats/static-stats.plist" atomically:YES];
NSLog(#"written file");
because you don't check if the file was really written with success or not.
you should write :
if([tempDict writeToFile:#"~/Library/Application Support/Staying Afloat/stats/static-stats.plist" atomically:YES]) {
NSLog(#"written file");
} else {
NSLog(#"file not written");
}
WriteToFile method returns a Boolean.
I always use NSUserDefaults which takes care of everything for you with things like user prefs or storing app states between running. Off the top of my head I'd suggest you haven't got the right privileges to write a plist and what happens if you accidentally destroy a vital key and value for the os? Have a look at
Best practices for handling user preferences in an iPhone MVC app?
Are you sure -writeToFile:atomically: returns YES?
Related
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 recently started Application development on MAC OS 10.6, I am trying to modify a "key/value" pair in a local JSON file on my MAC machine using SBJSON. I have successfully read the value of a key, but I am not able to get that how to modify the value of a key and synchronize this to the JSON file. Lets suppose, I have a following JSON Data int o a local file:
{
"name": {
"fName":"John",
"lName":"Doe"
}
}
And i want to change the value of "fName" to something else, like Robert.
I have tried alot searching about it, but got no clue... Can anyone help me.
I am using SBJSON Framework!
Code:
NSString *filePath = #"/Users/dev/Desktop/SQLiteFile/myJSON2.json";
NSData *myData = [NSData dataWithContentsOfFile:filePath];
NSString *responseString = [[NSString alloc] initWithData:myData encoding:NSUTF8StringEncoding];
NSLog(#"FILE CONTENT : %#", responseString);
SBJsonParser *jsonParser = [[SBJsonParser alloc] init];
NSDictionary * dictionary = (NSDictionary*)[jsonParser objectWithString:responseString error:NULL];
[dictionary setObject:#"Robert" forKey:#"fName"];
//
// Code for writing this change into the file, which i needed.
//
[jsonParser release];
You want a mutable deep copy of your dictionary. Then you'll be able to modify it.
The example below should take a link from m3u playlist and add it to anArray. (So I will get the NSArray(NSMutableArray) with certain links in it)
NSString *fileContents = [NSString stringWithContentsOfFile:#"myfile.m3u" encoding:NSUTF8StringEncoding error:NULL];
NSArray *lines = [fileContents componentsSeparatedByString:#"\n"];
NSLog (#"%#",lines);
All the time I had (null) in NSLog Message.
All the time when I try NSLog or if/else statement to check is there is link in array it gives me the null object in it.
After that I thought the problem was in m3u type and I've tried to change type in txt and read. (For those who don't know, M3U is just the text in UTF-8 encoding and the changing type should give the result)
Then I've tried the .txt files but it doesn't work too. So there is the code of it.
//Check if there is my file
NSString *addPath = [[NSBundle mainBundle] pathForResource:#"somefile" ofType:#"m3u" ];
if ([fileMgr fileExistsAtPath:addPath] ) {
NSLog(#"Yes.We see the file");
}
else {
NSLog(#"Nope there is no file");
}
//Rename
NSString *path1 = addPath;
NSString *theNewFilename = [path1 stringByReplacingOccurrencesOfString:#"m3u" withString:#"txt"];
NSLog(#"Renamed file adress is %#", theNewFilename);
//Check if there is our renamed file(file manager was allocated before)
NSString *addPath1 = [[NSBundle mainBundle] pathForResource:#"somefile" ofType:#"txt" ];
if ([fileMgr fileExistsAtPath:addPath1] ) {
NSLog(#"Yes we had the renamed file");
}
else {
NSLog(#"No we don't");
}
Checking is there is m3u file worked fine. I had Addres to Renamed file too. But when it was checking is there is renamed file, there was no file (null in NSLog).
After all that stuff, and without any hope to reach my destination I've tried to read txt file line by line separated by /n with 5 links in it.
NSString *fileContents1 = [NSString stringWithContentsOfFile:#"myfile.txt" encoding:NSUTF8StringEncoding error:NULL];
NSArray *lines1 = [fileContents1 componentsSeparatedByString:#"\n"];
NSLog (#"%#",fileContents1);
NSLog (#"%#",lines1);
Both Messages were NULL
One more thing all this stuff I tried to make in -(IBAction)fileRead { } linked to button
(Yes I've presed button every time to check my NSLog)Program was checked in iPhone Simulator. Will be glad if someone say what is the trouble. Also if there is easier way to make this with url. (Tried Couple times with NSUrl and had Nothing but null )
Just because you've changed the path doesn't mean that you've renamed/moved/copied an item, path is just a string. Use NSFileManager methods like
– moveItemAtURL:toURL:error: or
– moveItemAtPath:toPath:error:.
Also, NSString doesn't care about extension, so it's completely safe to read your m3u file to NSString, no need to rename it.
NSString *addPath = [[NSBundle mainBundle] pathForResource:#"somefile" ofType:#"m3u" ];
if ([fileMgr fileExistsAtPath:addPath] ) {
NSLog(#"Yes.We see the file");
NSString *fileContents1 = [NSString stringWithContentsOfFile:addPath encoding:NSUTF8StringEncoding error:NULL];
NSArray *lines1 = [fileContents1 componentsSeparatedByString:#"\n"];
NSLog (#"%#",fileContents1);
NSLog (#"%#",lines1);
}
else {
NSLog(#"Nope there is no file");
}
I'm monitoring a folder, when a user copies a file into the folder, I need to perform an action. However, when I perform the action the file has no contents yet. Is there a way to check that the copied file is ready?
NSFileManager got a method - (BOOL)fileExistsAtPath:(NSString *)path
So your code would look like:
([[[NSFileManager alloc] init] fileExistsAtPath:myPath] == true)
{ do sth.; }
Instead of the if clause you might want to choose a while loop, but i suppose you know how to deal with that ;)
Hope I could help.
I finally got it. I can use NSPasteboard to check what file is currently being copied.
With this information, I can compare the file size between the source and destination to know when the copy is complete.
NSPasteboard *pasteboard = [NSPasteboard generalPasteboard];
NSArray *classes = [[NSArray alloc] initWithObjects:[NSURL class], nil];
NSDictionary *options = [NSDictionary dictionaryWithObject: [NSNumber numberWithBool:YES] forKey:NSPasteboardURLReadingFileURLsOnlyKey];
NSArray *copiedItems = [pasteboard readObjectsForClasses:classes options:options];
I'm trying to combine images in my app into one file and write it to disk.
NSMutableArray *array = [NSMutableArray arrayWithObjects:
[NSData dataWithContentsOfFile:#"0.png"],
[NSData dataWithContentsOfFile:#"1.png"],
[NSData dataWithContentsOfFile:#"2.png"],
nil];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:array];
NSError *error = nil;
NSString *path=#"/Users/myusername/Desktop/_stuff.dat";
[data writeToFile:path options:NSDataWritingAtomic error:&error];
or
NSArray *array = [NSArray arrayWithObjects:
[NSImage imageNamed:#"0"],
[NSImage imageNamed:#"1"],
[NSImage imageNamed:#"2"],
nil];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:array];
NSError *error = nil;
NSString *path=#"/Users/myusername/Desktop/_stuff.dat";
[data writeToFile:path options:NSDataWritingAtomic error:&error];
But both produce a file that is 4KB (empty). If I NSLog the error it is (null). Am I making the data the wrong way?
Edit: If I open the resulting file with a text editor, it looks like this:
I wrote a quick example:
Missing: memory management / error handling / proper file handling
// Archive
NSMutableArray *array = [[NSMutableArray alloc] init];
NSString * input = #"/Users/Anne/Desktop/1.png";
[array addObject:[NSData dataWithContentsOfFile:input]];
[array addObject:[NSData dataWithContentsOfFile:input]];
[array addObject:[NSData dataWithContentsOfFile:input]];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:array];
NSString *path = #"/Users/Anne/Desktop/archive.dat";
[data writeToFile:path options:NSDataWritingAtomic error:nil];
// Unarchive
NSMutableArray *archive = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
NSData * firstObject = [archive objectAtIndex:0];
NSString * output = #"/Users/Anne/Desktop/2.png";
NSURL *fileURL = [[NSURL alloc] initFileURLWithPath:output];
[firstObject writeToURL:fileURL atomically:YES];
You can also add NSImages to the NSMutableArray:
NSString * input = #"/Users/Anne/Desktop/1.png";
NSImage *image = [[NSImage alloc] initWithContentsOfFile: input];
[array addObject:image];
But that will significantly increase the file size.
Response to the following comment:
So if I only need to access an image at runtime (in the archive), is there a way to access that image at an index without unarchiving the whole thing? Seems like unnecessary overhead to me.
I assume you're still struggling with this problem?
Hiding (or encrypting) app resources?
Like i mentioned earlier, combining all files into one big file does the trick.
Just make sure you remember the file-length of each file and file-order.
Then you can extract any specific file you like without reading the whole file.
This might be a more sufficient way if you only need to extract one file at the time.
Quick 'dirty' sample:
// Two sample files
NSData *fileOne = [NSData dataWithContentsOfFile:#"/Users/Anne/Desktop/1.png"];
NSData *fileTwo = [NSData dataWithContentsOfFile:#"/Users/Anne/Desktop/2.png"];
// Get file length
int fileOneLength = [fileOne length];
int fileTwoLength = [fileTwo length];
// Combine files into one container
NSMutableData * container = [[NSMutableData alloc] init];
[container appendData:fileOne];
[container appendData:fileTwo];
// Write container to disk
[container writeToFile:#"/Users/Anne/Desktop/container.data" atomically:YES];
// Read data and extract sample files again
NSData *containerFile = [NSData dataWithContentsOfFile:#"/Users/Anne/Desktop/container.data"];
NSData *containerFileOne =[containerFile subdataWithRange:NSMakeRange(0, fileOneLength)];
NSData *containerFileTwo =[containerFile subdataWithRange:NSMakeRange(fileOneLength, fileTwoLength)];
// Write extracted files to disk (will be exactly the same)
[containerFileOne writeToFile:#"/Users/Anne/Desktop/1_extracted.png" atomically:YES];
[containerFileTwo writeToFile:#"/Users/Anne/Desktop/2_extracted.png" atomically:YES];
// Only extract one file from the container
NSString * containerPath = #"/Users/Anne/Desktop/container.data";
NSData * oneFileOnly = [[NSFileHandle fileHandleForReadingAtPath:containerPath] readDataOfLength:fileOneLength];
// Write result to disk
[oneFileOnly writeToFile:#"/Users/Anne/Desktop/1_one_file.png" atomically:YES];
Tip:
You can also save the 'index' inside the container file.
For example: The first 500 bytes contain the required information.
When you need a specific file: Read the index, get the file position and extract it.
You are archiving a NSMutable array of NSImage. This two classes conform to the NSCoding protocol required by NSKeyedArchiver, so I don't see where would be your problem.
So, here are many ideas to test.
First, are you sure that the data you think you have are valid? In your first code snippet, you write [NSData dataWithContentsOfFile:#"0.png"]. This method expects an absolute file path.
Assuming the problem is not in your code, just in your question, let's continue:
Do you have something different than nil in the variable data after your archiving? Ie, after the assignement to data, can you add this code. If the assertion fail, you will get an exception at runtime:
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:array];
NSAssert(nil != data, #"My object data is nil after archiving");
If the problem was not here, what is the return of the line [data writeToFile:path options:NSDataWritingAtomic error:&error];
(Not the variable error, but the return value of the call to the method - writeToFile: options: error:)
What happens if you simplify your code and just do this:
result = [NSKeyedArchiver archiveRootObject:data
toFile:archivePath];
If everything was ok, have you tried to unarchive your file with NSKeyedUnarchiver?
The problem is that [NSData dataWithContentsOfFile:#"0.png"] looks for the file "0.png" in the current directory, but what the application thinks of as the current directory is probably not the place you're expecting. For graphical apps, you should always either use an absolute path or a path relative to some place that you can get the absolute path of (e.g. your app bundle, the application support directory, some user-selected location).
For command-line tools, using the current directory is more common. But I doubt that's the case here.
Another thing I noticed on Mavericks and up is that the folders in the path must be in existence. Meaning you must create the folder structure prior to saving into that folder. If you try to write to a folder on the desktop or elsewhere, even with sandboxing off, it will fail if the folder does not exist. I know this has been answered already, but I found that my issue continued regardless, but once I make sure that the folder structure was in place, I could do my writing to that folder.
On a side note: I'm sure that you could do this from NSFileManager, and I'll be doing that myself once I finalize my app structure, but hope this helps someone else lost in the sauce.