Proper way to giving name to file when [NSData writeToFile:] used - ios

Question

I'm using that code to save downloaded videos from internet to application document folder:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *save_it = [documentsDirectory stringByAppendingPathComponent:video_filename];
NSError *error;
BOOL success = [fileData writeToFile:save_it options:0 error:&error];
if (!success) {
NSLog(#"writeToFile failed with error %#", error);
}
it works, but if there is a slash "/" in the video_filename it breaks because of slash is directory seperator, I know.
For example when video_filename is : Best Video / Best Song Ever.3gpp , log says:
{NSFilePath=/Users/Apple/Library/Developer/CoreSimulator/Devices/5A7D36F5-6EDB-495D-9E8E-B9EB22E5357C/data/Containers/Data/Application/B1D0AC48-D84C-4A0D-9F09-08BF4C45DD32/Documents/Best Video / Best Song Ever.3gpp, NSUnderlyingError=0x7d339430 "The operation couldn’t be completed. No such file or directory"}
I don't know is there any other special character that will make crashing,
So what is the best way of cleaning these special characters from nsstring ?
We can make SEO friendly urls in PHP, I'm searching a function like that to do this.

Answer 1

The first problem I see here is that your file path includes some spaces. in the example you gave, the value of video_filename variable is "Best Video / Best Song Ever.3gpp" which includes spaces around the slash. You first have to delete the spaces, this might help you do that:
NSArray *components = [video_filename componentsSeparatedByString:#"/"];
for (NSInteger i = 0, i < components.count, ++i) {
NSString *string = components[i];
string = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
components[i] = string;
}
NSString *path = [components componentsJoinedByString:#"/"];
If I understood correctly, your video_filename might be either in the form xxx.3gpp or yyy/xxx.3gpp. If it's the format of yyyy/xxxx.3gpp, you first have to create a directory named yyyy and then save the file to that directory.
This might help you do that:
- (void)createDirectory:(NSString *)directoryName
atFilePath:(NSString *)filePath
{
NSString *filePathAndDir = [filePath
stringByAppendingPathComponent:directoryName];
NSError *error;
if (![[NSFileManager defaultManager] createDirectoryAtPath:filePathAndDir
withIntermediateDirectories:NO
attributes:nil
error:&error]) {
NSLog(#"Create directory error: %#", error);
}
}
and the way you would use this is
[self createDirectory:components[0] atFilePath:documentsDirectory];
hope this helps!

Answer 2

So if your filename is actually "Best Video / Best Song Ever.3gpp" I am sorry but nothing easy comes to mind.
Now if Best Video is a folder where you will save your file you can use :
+(NSString*) getPathToFolder:(NSString*) folderName {
NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
NSString *folderPath = [documentsPath stringByAppendingPathComponent:folderName];
NSFileManager *fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath:folderPath]) {
NSLog(#"Creating a new folder at\n%#", folderPath) ;
[fileManager createDirectoryAtPath:folderPath withIntermediateDirectories:NO attributes:nil error:nil];
}
return folderPath ;
}
This will check if your folder exist or not, if it does not exists then it will create it.
it will return the path you will want to use to save your file.
Now regarding the naming of the files, using spaces is highly unadvisable, I suggest using :
NSString* pathWITHSpaces ;
NSString* pathWithoutSpaces = [pathWITHSpaces stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
Hope this helps a bit