I have been using a plist to store data in my app. I have been able to write and read from the plist with no problem. I created this plist in Xcode, adding the rows of numbers, dictionaries, and arrays myself. However, I would like to be able to reset the plist to the original state, and there must be an easier way to do this than writing a 0 or nil value to every entry in the plist. So what is the easiest way to reset the plist to its initial default state?
The simplest thing would be to delete the file using NSFileManager, like this:
[[NSFileManager defaultManager] removeItemAtPath:plistPath error:NULL];
Or if you don't want to do that, assuming the plist is a dictionary, just load the one from your application bundle and then overwrite the one in your documents, like this:
NSDictionary *originalPlist = [NSDictionary dictionaryWithContentsOfFile:bundleFile];
[originalPlist writeToFile:documentsFile atomically:YES];
Which will overwrite the saved file with the original file.
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:#"mobile-watchlist.plist"];
[fileManager removeItemAtPath: fullPath error:NULL];
You could also try to just rename your Plist. Thats the least work i think.
Related
I am using the solution found here: Save NSArray to File and I am just wondering what type of file format I should save my array as. Can I just use .txt?
Any format. iOS writeToPath: does not read the extension. You can even make up weird file names.
Take the codes from your reference question as example,
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:FILE_NAME];
[myArray writeToFile:filePath atomically:YES];
the FILE_NAME could be in any ASCII values.
The writeToFile of an array object creates a property list file. So, while you can use whatever extension you want, it's generally good style to use the plist extension.
I create a file with attribute NSFileappendonly, i am thinking this is enough to create readonly file in ios.My problem is try to remove the file from device it returns error.Please anyone help me..
A 513 states you do not have permission to write to that folder NSFileWriteNoPermissionError. You need to make sure you are only trying to write to one of the 3 folders in your app's dir (Documents, Temp, or Cache). Generally you use the Documents folder. (Trying to write directly to the main bundle can cause the error you are having)
iOS Environment
You can remove a file with NSFileManager but only if your app is signed and you are attempting to remove from one of the 3 allowed folders. Those 3 folders are only accessible by your app.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectoryPath = [paths objectAtIndex:0];
NSString *yourFile = [documentsDirectoryPath stringByAppendingPathComponent:#"yourFile.txt"];
NSFileManager *fileManager = [NSFileManager defaultManager];
[fileManager removeItemAtPath:yourFile error:NULL];
Sorry I saw similar questions but they don't seem to have some full answers for me. And i try to put it in order so that people will not hate me or my poor english.
I am working with Xcode 4.2 with storyboard and ARC
I can read from my plist file. My task is simply to write back the updated value(s) to my plist file.
My plist is contain in "supporting files" sub folder of the main folder (where story-board is things goes). the file is call Global.plist and GlobalValue2 is a element of the file type string.
So the read file part looks like this
NSString *plistfile = [[NSBundle mainBundle] pathForResource:#"Global" ofType:#"plist"];
NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:plistfile];
FirstValueTextBox.text = [[dict valueForKey:#"GlobalValue1"] stringValue];
learn it from some handy youtube video works just fine. updates the value to my text box.
The real problem comes in when I write back my plist file. When i try the following
NSString *plistfile = [[NSBundle mainBundle] pathForResource:#"Global" ofType:#"plist"];
NSMutableDictionary *dict = [NSMutableDictionary
dictionaryWithContentsOfFile:plistfile];
[dict setValue:#"ABC" forKey:#"GlobalValue2"];
SecondValueTextBox.text = [dict valueForKey:#"GlobalValue2"];
[dict writeToFile:plistfile atomically:YES];
the result is I really saw a updated value pop up on the second text box, but the plist file remain unchanged.
The following are the break down of my questions and my guess for the problem
I try to use NSDictionary(not NSMutableDictionary) and call setValue (crash in runtime)
my guess: NSDictionary object itself is readonly so it crash me when i say add value. But why don't it error me when in coding time? if the object is readonly
I use NSMutableDictionary can call setValue. it doesn't crash me and when i call the updated value at "SecondValueTextBox.text = [dict valueForKey:#"GlobalValue2"];" it really return me the updated value. but the content inside of the plist file is not changed. Which is the result I have right now.
my guess: after some search here and there I think "supporting files" is read only too. pure guess did see anyone directly talk about it.
I did try to move on a little more and some people talks about a "document folder" in Xcode that is a read and write place. I think people also talk about write a code to access that folder. Can someone show me the code here.
My last question, can I hook up my Xcode to that "document folder" or where can i see it(the real file folder structure is different from inside Xcode I think). So that i can see and edit my plist file for testing, and i can see the real result without using codes and stuff
I will be much appreciated if people can tell me my guess is right or wrong and the answer to my 3 and 4 question.
In order for your changes to be persisted in your plist, you would indeed need ot copy it from the resource bundle to the documents dirtectory on launch of the application, then use the plist in the documents to read and write.
Here is how you can copy the file:
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *plistPath = [documentsDirectory stringByAppendingPathComponent:#"Global.plist"];
if ([fileManager fileExistsAtPath:plistPath] == NO) {
NSString *resourcePath = [[NSBundle mainBundle] pathForResource:#"Global" ofType:#"plist"];
[fileManager copyItemAtPath:resourcePath toPath:plistPath error:&error];
}
I am posting this question because I had a complete answer for this written out for another post, when I found it did not apply to the original but I thought was too useful to waste. Thus I have also made this a community wiki, so that others may flesh out question and answer(s). If you find the answer useful, please vote up the question - being a community wiki I should not get points for this voting but it will help others find it
How can I get a path into which file writes are allowed on the iPhone? You can (misleadingly) write anywhere you like on the Simulator, but on the iPhone you are only allowed to write into specific locations.
There are three kinds of writable paths to consider - the first is Documents, where you store things you want to keep and make available to the user through iTunes (as of 3.2):
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
Secondly, and very similar to the Documents directory, there is the Library folder, where you store configuration files and writable databases that you also want to keep around, but you don't want the user to be able to mess with through iTunes:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
NSString *libraryDirectory = [paths objectAtIndex:0];
Note that even though the user cannot see files in iTunes using a device older than 3.2 (the iPad), the NSLibraryDirectory constant has been available since iPhoneOS 2.0, and so can be used for builds targeting 3.0 (or even earlier if you are still doing that). Also the user will not be able to see anything unless you flag an app as allowing users to modify documents, so if you are using Documents today you are fine as long as you change location when updating for support of user documents.
Last there is a cache directory, where you can put images that you don't care exist for the long term or not (the phone may delete them at some point):
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString *cachePath = [paths objectAtIndex:0];
BOOL isDir = NO;
NSError *error;
if (! [[NSFileManager defaultManager] fileExistsAtPath:cachePath isDirectory:&isDir] && isDir == NO) {
[[NSFileManager defaultManager] createDirectoryAtPath:cachePath withIntermediateDirectories:NO attributes:nil error:&error];
}
Note that you have to actually create the Caches directory there, so when writing you have to check and create every time! Kind of a pain, but that's how it is.
Then when you have a writable path, you just append a file name onto it like so:
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"SomeDirectory/SomeFile.txt"];
or
NSString *filePath = [cachePath stringByAppendingPathComponent:#"SomeTmpFile.png"];
Use that path for reading or writing.
Note that you can make subdirectories in either of those writable paths, which one of the example string above is using (assuming one has been created).
If you are trying to write an image into the photo library, you cannot use file system calls to do this - instead, you have to have a UIImage in memory, and use the UIImageWriteToSavedPhotosAlbum() function call defined by UIKit. You have no control over the destination format or compression levels, and cannot attach any EXIF in this way.
Thanks to Kendall & Dave, above, and I thought this amendment was useful to bring up. When using for one-off debug code, I used this trick from Mike Ash's NSBlog to eliminate the temporary variables isDir & error, minimizing the number of lines and making the verbosity almost bearable:
NSFileHandle *dumpFileHandle = nil;
#ifdef DEBUG
NSString *cachePath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) objectAtIndex:0];
if (![[NSFileManager defaultManager] fileExistsAtPath:cachePath isDirectory:&(BOOL){0}])
[[NSFileManager defaultManager] createDirectoryAtPath:cachePath withIntermediateDirectories:YES attributes:nil error:&(NSError*){nil}];
NSString *dumpPath = [cachePath stringByAppendingPathComponent:#"dump.txt"];
[[NSFileManager defaultManager] createFileAtPath:dumpPath contents:nil attributes:nil];
[(dumpFileHandle = [NSFileHandle fileHandleForWritingAtPath:dumpPath]) truncateFileAtOffset:0];
#endif
if (dumpFileHandle) [dumpFileHandle writeData:blah];
I am having a hard time figuring out how to get the property list file that was created using Xcode. I created a property list file using array with NSString members. I want to grab that file and get all the NSString members and save it to a UITextField. But my problem is that I can't see that file. I don't know if I'm looking in the wrong path, or I don't know where the property file is saved.
Most likely, if the file was added via Xcode, the file is in your bundle. To open it use:
NSDictionary *plist = [NSDictionary arrayWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"NameOfFile" ofType:#"plist"]];
Run this in the simulator and then look in the Finder, in Library/Application Support/iPhone Simulator/Applications/... to see if you can find the file, open it in and double check it to make sure Xcode added the file.
To make a copy in your Documents folder:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:#"My.plist"];
if (![plist writeToFile:path atomically:YES])
NSLog(#"not successful in writing the high scores");