renaming and saving in NSDocumentsDirectory - iphone

Question

Its like this, in my app, I have a UIScrollView on it is a thumbnail view, they are images from my NSCachesDirectory.
I saved them from my picker then named them in my array like: images0.png,images.1.png... etc
So for example I have images in my directory this way : images0.png, images1.png, images2.png, images3.png.
Then I delete images1.png, the remaining images will be like this : images0.png,images2.png, images3.png right?
What I wanted to achieve is get the images in NSDocumentsDirectory then renamed them AGAIN or sort them again like images0.png, images1.png, images2.png...etc again?
is this possible? hope you could help me.

Answer 1

Use this NSFileManger moveItemAtPath: toPath: error: but you should supply the toPath:same_path_but_different_filename. This moves the file to a new path with new file name that you provide. see this
Since it seems you want the whole logic to rename your images file, here is the code you can try provided the files are in the Document directory
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString * oldPath =[[NSString alloc]init];
NSString * newPath =[[NSString alloc]init];
int count=0;
for (int i=0; i<=[[fileManager contentsOfDirectoryAtPath:documentsDirectory error:nil]count]; i++) {
oldPath=[documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"images%d.png",i]];
if ([fileManager fileExistsAtPath:oldPath]) {
newPath=[documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"images%d.png",count]];
[fileManager moveItemAtPath:oldPath toPath:newPath error:nil];
count+=1;
}
}

Answer 2

Apple doesnot allow renameing of file saved. So alternative is to get all contents at document directory like this:
NSArray *directoryContent = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:yourDocDirPath error:NULL];
Now sort like this:
NSSortDescriptor * descriptor = [NSSortDescriptor sortDescriptorWithKey:nil ascending: YES comparator:^NSComparisonResult(id obj1, id obj2){
return [obj1 compare: obj2 options: NSNumericSearch];
}];
NSArray * sortedDirectoryContent = [directoryContent sortedArrayUsingDescriptors:[NSArray arrayWithObject: descriptor]];
We have sorted array rewrite all files with new name:
for(NSString *fileName in sortedDirectoryContent)
{
NSString *filePath = [yourDocDirPath stringByAppendingPathComponent:fileName];
NSData *fileData = [[NSData alloc]initWithContentsOfFile:filePath];
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
[[NSFileManager defaultManager] removeItemAtPath:filePath error:nil];
if(fileData)
{
NSString *newFilePath = [yourDocDirPath stringByAppendingPathComponent:#"New Name here"];
[fileData writeToFile:newFilePath atomically:YES];
}
}
else
{
if(fileData)
{
NSString *newFilePath = [yourDocDirPath stringByAppendingPathComponent:#"New Name here"];
[fileData writeToFile:newFilePath atomically:YES];
}
}
}