So I have encoded a bunch of objects for writing, but I'm having trouble with the file management. I can't seem to open the existing file, or create a new file.
I've tried creating an empty file of the same name, or just creating a new file. It doesn't seem to respond (or do anything at all for that matter).
edit So I've followed some of the advice here, and now I'm getting a bad access crash.
Here's where I get the path:
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
filePath = [documentsDirectory stringByAppendingPathComponent:@"/bucketListData.dat"];
And here's the modified method.
-(void) writeFile
{
NSData *encodedObject;
encodedObject = [NSKeyedArchiver archivedDataWithRootObject: bucketItems];
NSFileHandle *file;
file = [NSFileHandle fileHandleForReadingAtPath:filePath];
if(file == nil)
{
NSLog(@"Failed to open a file handle for writing. Attempting to create a file.");
[[NSFileManager defaultManager] createFileAtPath:filePath contents:nil attributes:nil];
file = [NSFileHandle fileHandleForReadingAtPath:filePath];
if(file == nil)
{
NSLog(@"Unable to create new file.");
}
}
[file writeData: encodedObject];
[file closeFile];
}
You don't have permissions to write to root, you can only access your sandbox, and you are creating a read-only handle. Try this way:
NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *filePath = [docDir stringByAppendingPathComponent:@"bucketListData.dat"];
NSFileHandle *file = [NSFileHandle fileHandleForWritingAtPath:filePath];
if (!file) {
NSLog(@"Attempting to create the file");
if (![[NSFileManager defaultManager] createFileAtPath:filePath
contents:nil
attributes:nil]) {
NSLog(@"Failed to create file");
}
else {
file = [NSFileHandle fileHandleForWritingAtPath:filePath];
}
}
NSLog(@"File handle: %@", file);
You are trying to open a file at the root of the filesystem, but you don't have access to that on iOS. Create the file in the documents directory instead:
NSData* encodedObject = [NSKeyedArchiver archivedDataWithRootObject: bucketItems];
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString* basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
NSString* path = [basePath stringByAppendingPathComponent:@"bucketListData.dat"];
NSFileHandle* file = [NSFileHandle fileHandleForReadingAtPath:path];
You need to write the file at the documents directory. And then use stringByAppendingPathComponent tu create the full path. This should work, I hope this helps...
-(void) writeFile
{
NSData *encodedObject;
encodedObject = [NSKeyedArchiver archivedDataWithRootObject: bucketItems];
NSFileHandle *file;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory;
if(paths && [paths count]>0){
documentsDirectory=[paths objectAtIndex:0];
file = [NSFileHandle fileHandleForReadingAtPath:[documentsDirectory stringByAppendingPathComponent:@"/bucketListData.dat"]];
if(file == nil)
{
NSLog(@"Failed to open a file handle for writing. Attempting to create a file.");
[[NSFileManager defaultManager] createFileAtPath:[documentsDirectory stringByAppendingPathComponent:@"/bucketListData.dat"] contents:nil attributes:nil];
file = [NSFileHandle fileHandleForReadingAtPath:[documentsDirectory stringByAppendingPathComponent:@"/bucketListData.dat"]];
if(file == nil)
{
NSLog(@"Unable to create new file.");
}
}
[file writeData: encodedObject];
[file closeFile];
}
}
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