I'm creating an app with iCloud. But I have some problems.
It creates directory on iCloud using NSFileWrapper, then it creates NSData (text) file in NSFileWrapper directory.
I'm using this code to convert NSData to NSString:
text=[NSString stringWithUTF8String:[fileData bytes]];
And it works correctly only on the device, which creates this text file. On other devices file is loaded successfully, but when I try to convert or print it (or other call methods), result is **BAD_ACCESS** and object doesn't exist (retain count of file data is 2).
Any ideas?
I think you should be converting it to a string like this:
NSString *string = [[NSString alloc] initWithData:[fileData bytes] encoding:NSUTF8Encoding];
Related
I am wanting to write my own logs to a text file on my iPhone. I wrote up a quick method that writes a string to a file. Right now it saves it into the Documents directory, which, if on the device is going to be a pain to get off, since I can't just browse to it. Is there a better way to quickly get this file off the device after I have written to it?
/**
* Logs a string to file
*
* #version $Revision: 0.1
*/
+ (void)logWithString:(NSString *)string {
// Create the file
NSError *error;
// Directory
NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:#"Documents"];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:#"log.txt"];
// Get the file contents
NSData *localData = [NSData dataWithContentsOfFile:filePath];
if (localData) {
NSString *logString = [[NSString alloc] initWithData:localData encoding:NSUTF8StringEncoding];
string = [logString stringByAppendingFormat:#"%#\n", string];
[logString release];
}
// Write to the file
[string writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:&error];
}//end
Add Application supports iTunes file sharing to your application target's build info in Xcode:
Then, you can easily browse, retrieve and delete any files created by the app from iTunes, right under Devices > Your device > Apps > File Sharing:
You may have to capture what number of logs you have created so far and create a new name for each log biased on that.
So you might save your last made logs name as a string in NSUserDefaults and get the number off the end of that and add one onto that captured int ready for the next name.
So if you have #"Log4" you can get the 4 out of that and make it 5 so that the next log is named "Log5"
Just my 2 cents :P
With regard to the 'How to get the file' part of the question
iExplorer, previously iPhone Explorer allows you to view your apps, including their documents folder without jailbreaking your devices.
In my experience (albeit of an older version), getting the files from the phone can be a little temporamental (i.e. I drag a file onto my desktop and although it creates the file, it doesn't write any of the data), you can get the files from your device.
My app parses an xml file from my server, but I want to store parsed xml file and next start of my app, controller initially should load stored xml file, then controller should parse it again to check that there may be an update I did on xml file, if there is, new elements parsed should also be stored again.
I am referring to those app such as magazines, newspaper apps. When you open those kind of apps, it loads stored data that was downloaded previous session. Yet, after it loads, it starts to update the data, and it stores new update again.
Where do I start? What do you guys suggest?
Thanks in advance...
You can use CoreData or SQLite (use Objective-C wrapper FMDB https://github.com/ccgus/fmdb) to persist your XML. Then update the database everytime you see a unique id. Depends on how your XML data is.
It's actually quite easy to store to the documents directory. For example:
NSData *data; //this is your xml file
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docs = [paths objectAtIndex:0];
NSString *filename = [NSString stringWithFormat:#"test.xml"];
NSString *path = [docs stringByAppendingPathComponent:filename];
[data writeToFile:path atomically:YES];
Then to retrieve it later, you can get the path like above, but retrieve the file instead of writing it:
NSData *data = [NSData dataWithContentsOfFile:path];
either CoreData or SQLite can do the trick
My app is accessing data from a remote XML file. I have no issues receiving and parsing the data. However, I'd like to take the most current XML data and store it locally so - in the event that the user's internet service isn't available - the local data from the previous load is used.
Is there a simple way to do this? Or am I going to have to create an algorithm that will create a plist as the xml data is parsed? That seems rather tedious... I was wondering if there was an easier way to save the data as a whole.
Thanks in advance!
I don't know what format your XML data is in as you receive it, but using NSData might be helpful here, because it has very easy-to-use methods for reading/writing data from either a URL or a pathname.
For example:
NSURL *url = [NSURL URLWithString:#"http://www.fubar.com/sample.xml"];
NSData *data = [NSData dataWithContentsOfURL:url]; // Load XML data from web
// construct path within our documents directory
NSString *applicationDocumentsDir =
[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSString *storePath = [applicationDocumentsDir stringByAppendingPathComponent:#"sample.xml"];
// write to file atomically (using temp file)
[data writeToFile:storePath atomically:TRUE];
You can also easily convert an NSData object to/from a raw buffer (pointer/length) in memory, so if your data is already downloaded you might do:
NSData *data = [NSData dataWithBytes:ptr length:len]; // Load XML data from memory
// ... continue as above, to write the NSData object to file in Documents dir
i'm new to iPhone programming and coding in XCode SDK.I want to access and read the configuration file which i have placed in Resource folder in XCode,my configuration file looks like this
#key=value$
#vinu=flower$
#cathy=fruit$
I want to compare the key and access the value from configuration file.
Since i'm working with iPhone OS, i cant use NSWorkspace.Hence i'm using NSFileHandle.
This is how my code looks like,
NSString *path = [[NSBundle mainBundle] pathForResource:#"configuration" ofType:#"txt"];
NSFileHandle *readHandle = [NSFileHandle fileHandleForReadingAtPath:path];
NSString *txtString = [[NSString alloc] initWithData:
[readHandle readDataToEndOfFile] encoding:NSUTF8StringEncoding];
please let me know is the procedure correct, and how to proceed. ??
Thank You.
Do yourself a favor and save it as a plist, and not a straight text file.
However, if you need to read it in like that, the simplest way is to read it into a string and then go from there, ie:
NSString * fileContents = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
If the file is super large and the only reasonable way to read it is line-by-line, then you can quickly see that this is something that has come up before (Particularly: Objective-C: Reading a file line by line).
How does one read a data file in an iPhone project? For example, lets say I have a static file called "level.dat" that is structured as follows:
obstacles: 10
time: 100
obstacle1: 10,20
...
I would like to read the contents of the file into a NSString then do the parsing. How do I read the contents of a file into a string? Also, where in the project should the "level.dat" file reside? Should it be under "Resources" or just in the main directory?
Thanks in advance!
See this answer: How to fopen() on the iPhone? which shows how to get access to resources in your bundle. Once you have the path, just use [NSString stringWithContentsOfFile:encoding:error:].
NSString *path = [[NSBundle mainBundle] pathForResource: #"level" ofType: #"dat"]
NSError *error = nil;
NSString *data = [NSString stringWithContentsOfFile: path
encoding: NSUTF8StringEncoding
error: &error];
While this isn't what you asked for, consider turning your files into plists. You will have to reformat them into XML, but then you can load them straight into a NSDictionary with:
dict = [NSDictionary dictionaryWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"levels" ofType:#"plist"]];
Have you considered putting the data in an SQLite database instead of a flat file? I find that the API is very easy to use on the iPhone.
It is how I do all of my data storage on the phone now.
If you need help parsing the data string, there's a helpful article on Cocoa For Scientist