NSURL directory files - objective-c

Question

I have for example : www.example.com/ url.
Inside that URL there are few directories for example www.example.com/dir1/ and inside that there are images when clicked I get www.example.com/dir1/image1.jpg.
My problem is that I need to get all files inside www.example.com/dir1/ , so all images that are inside that directory on web. Based on that names I can get final url (like www.example.com/dir1/image1.jpg) but I need to get all the names of images and dunno how.
Thanks.

Answer 1

If you are seeing the apache directory listing you can parse that html and get all your .jpg files.
http://www.raywenderlich.com/14172/how-to-parse-html-on-ios is a tutorial on how to parse HTML

Answer 2

If this is on your server, you need some mechanism to retrieve the names of the files.
For example, if PHP, this is a script that returns a JSON response of all of the JPG/PNG files:
<?php
header('Content-type: application/json');
$files = scandir('.');
$images = array();
foreach ($files as $file)
{
switch(strtolower(substr(strrchr($file,'.'),1)))
{
case 'png':
case 'jpeg':
case 'jpg': $images[] = $file;
}
}
echo json_encode($images);
?>
You can then use NSURLConnection (or AFNetworking or whatever) to retrieve this and convert the JSON to a NSArray.
For example, using AFNetworking:
NSURL *url = [NSURL URLWithString:#"http://yourwebserver.com/some/path/images.php"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[op setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
if ([responseObject isKindOfClass:[NSArray class]])
[self doSomethingWithImageNames:responseObject];
else
NSLog(#"expected array, received: %#", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"AFHTTPRequestOperation error: %#", error);
}];
[op start];
Or NSURLConnection:
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
if (connectionError) {
NSLog(#"sendAsynchronousRequest error: %#", connectionError);
return;
}
NSError *jsonError = nil;
NSArray *imageNames = [NSJSONSerialization JSONObjectWithData:data options:0 error:&jsonError];
if (jsonError) {
NSLog(#"JSONObjectWithData error: %#", jsonError);
return;
}
[self doSomethingWithImageNames:imageNames];
}];
If you have to rely upon the HTML response, while you generally shouldn't use regular expressions, in this limited use case, you can probably get away with it. In my case, my web server reports links to the files using filename syntax, so I can grab those href tags with something like:
AFHTTPRequestOperation *op = [[AFHTTPRequestOperation alloc] initWithRequest:request];
op.responseSerializer = [AFHTTPResponseSerializer serializer];
[op setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
if (![responseObject isKindOfClass:[NSData class]]) {
NSLog(#"Was expecting `NSData` and got %#", responseObject);
return;
}
NSString *string = [[NSString alloc] initWithData:(NSData *)responseObject encoding:NSUTF8StringEncoding];
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"<a\\s[\\s\\S]*?href\\s*?=\\s*?['\"](.*?)['\"][\\s\\S]*?>"
options:NSRegularExpressionCaseInsensitive
error:&error];
NSMutableArray *results = [NSMutableArray array];
[regex enumerateMatchesInString:string
options:0
range:NSMakeRange(0, [string length])
usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {
[results addObject:[string substringWithRange:[result rangeAtIndex:1]]];
}];
[self doSomethingWithImageNames:results];
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(#"AFHTTPRequestOperation error: %#", error);
}];
[op start];