NSFileHandle fileHandleForWritingAtPath: return null!

user_135555 0
Viewed 13861

my iPad app has a small download facility, for which I want to append the data using an NSFileHandle. The problem is the creation call only returns null file handles. What could be the problem? Here is the three lines of code that are supposed to create my file handle:

NSString *applicationDocumentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
self.finalPath = [applicationDocumentsDirectory stringByAppendingPathComponent: self.fileName]; 
NSFileHandle *output = [NSFileHandle fileHandleForWritingAtPath:self.finalPath];

I checked the file path, and I could see nothing wrong.

TYIA

nsfilehandle cocoa-touch
2 Answers

Get documents directory path

+(NSURL *)getDocumentsDirectoryPath
{
    return [[[NSFileManager defaultManager]URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask]lastObject];
}

Save text to end of the file

if file doesnt exist create it and write data

+(void)saveText:(NSString *)textTobeSaved atPath:(NSString*)fileName
{
    NSString *filePath = [NSString stringWithFormat:@"%@.text",fileName];
    
    NSString *path = [[self getDocumentsDirectoryPath].path
                      stringByAppendingPathComponent:filePath];
    NSFileHandle *fileHandler = [NSFileHandle fileHandleForWritingAtPath:path];
    if(fileHandler == nil) {
        [[NSFileManager defaultManager] createFileAtPath:path contents:nil attributes:nil];
        fileHandler = [NSFileHandle fileHandleForWritingAtPath:path];
    } else {
        textTobeSaved = [NSString stringWithFormat:@"\n-----------------------\n %@",textTobeSaved];
        [fileHandler seekToEndOfFile];
    }
    
    [fileHandler writeData:[textTobeSaved dataUsingEncoding:NSUTF8StringEncoding]];
    [fileHandler closeFile];
}

get text from file with specified filename

+(NSString *)getTextFromFilePath:(NSString *)fileName
{
    NSString *filePath = [NSString stringWithFormat:@"%@.text",fileName];
    
    NSString *path = [[self getDocumentsDirectoryPath].path
                      stringByAppendingPathComponent:filePath];
    NSLog(@"%@",path);
    if(path!=nil)
    {
    NSString *savedString = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
    
    return savedString;
  }else{
    return @"";
  } 
}

Delete file

+(void)deleteFile:(NSString *)fileName
{
    NSString *filePath = [NSString stringWithFormat:@"%@.text",fileName];
    
    NSString *path = [[self getDocumentsDirectoryPath].path
                      stringByAppendingPathComponent:filePath];
    
    NSFileHandle *fileHandler = [NSFileHandle fileHandleForWritingAtPath:path];
    if(fileHandler != nil) {
        [[NSFileManager defaultManager]removeItemAtPath:path error:nil];
    }
    
}
user_20724160
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