NSURL does not support the use of curly braces (i.e. {}) in URLs. My application needs to talk to a server that requires the use of curly braces in the URL. I'm considering using bridges to write the networking code in Python or C++, or even rewriting the C code for NSURL to make it accept curly braces. Percent escapes are not accepted by my remote server.
Do I have any other good alternatives?
EDIT: Explained why addingPercentEscapesUsingEncoding and the like don't work for me here.
Will it work for you if you escape the braces?
This code:
// escape {} with %7B and %7D
NSURL *url = [NSURL URLWithString:#"http://somesite.com/%7B7B643FB915-845C-4A76-A071-677D62157FE07D%7D.htm"];
NSLog(#"%#", url);
// {} don't work and return null
NSURL *badurl = [NSURL URLWithString:#"http://somesite.com/{7B643FB915-845C-4A76-A071-677D62157FE07D}.htm"];
NSLog(#"%#", badurl);
Outputs:
2011-11-30 21:25:06.655 Craplet[48922:707] http://somesite.com/%7B7B643FB915-845C-4A76-A071-677D62157FE07D%7D.htm
2011-11-30 21:25:06.665 Craplet[48922:707] (null)
So, escaping seems to work
Here's how you can programmatically escape the url:
NSString *escapedUrlString = [unescaped stringByAddingPercentEscapesUsingEncoding: NSASCIIStringEncoding];
EDIT:
In your comment below, you said your server won't accept encoded braces and was there any other alternatives. First, I would try and get the server fixed. If that's not possible ... I haven't tried this with braces etc... but the layer below NS networking classes is CFNetworking.
See this:
http://developer.apple.com/library/ios/#documentation/Networking/Conceptual/CFNetwork/CFHTTPTasks/CFHTTPTasks.html#//apple_ref/doc/uid/TP30001132-CH5-SW2
From that doc:
CFStringRef url = CFSTR("http://www.apple.com");
CFURLRef myURL = CFURLCreateWithString(kCFAllocatorDefault, url, NULL);
CFStringRef requestMethod = CFSTR("GET");
....
Once again, haven't tried it and I'm running out. might try it later but if a layer isn't working your first options are to move down the stack.
Bryan's answer is perfectly great (+1 to him!), but another solution would be to use NSString's stringByAddingPercentEscapesUsingEncoding: method.
Like this:
NSString * originalURLAsString = [NSString stringWithString: #"http://somesite.com/{7B643FB915-845C-4A76-A071-677D62157FE07D}.htm"];
NSString * properlyEncodedString = [originalURLAsString stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding];
NSURL * url = [NSURL URLWithString: properlyEncodedString];
I hope this info helps you out!
To call using CFNetwork can use the follwoing
-(void)getDataFromUrl{
CFStringRef tempURLA = CFSTR("http://my.test.server/iostest/index.html?{\"a\":\"b\"}");
CFStringRef tempUrlSting = CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)tempURLA,CFSTR("{}"), CFSTR("\""), CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));
CFURLRef myURL = CFURLCreateWithString(kCFAllocatorDefault, tempUrlSting, NULL);
CFStringRef requestMethod = CFSTR("GET");
CFHTTPMessageRef myRequest = CFHTTPMessageCreateRequest(kCFAllocatorDefault, requestMethod, myURL,kCFHTTPVersion1_1);
CFStringRef headerFieldName = CFSTR("Accept");
CFStringRef headerFieldValue = CFSTR("text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
CFHTTPMessageSetHeaderFieldValue(myRequest, headerFieldName, headerFieldValue);
[self performHTTPRequest:myRequest];
}
-(void)performHTTPRequest:(CFHTTPMessageRef)request {
CFURLRef gotdatab = (__bridge CFURLRef)(CFBridgingRelease(CFHTTPMessageCopyRequestURL(request)));
// NSLog(#"(CFHTTPMessageRef request %#",gotdatab);
CFReadStreamRef requestStream = CFReadStreamCreateForHTTPRequest(NULL, request);
CFReadStreamOpen(requestStream);
NSMutableData *responseBytes = [NSMutableData data];
NSError *error;
while (TRUE) {
if (CFReadStreamHasBytesAvailable(requestStream)) {
UInt8 streambuffer[1024];
int readBytes = CFReadStreamRead (requestStream,streambuffer,sizeof(streambuffer));
NSLog(#"Read: %d",readBytes);
[responseBytes appendBytes:streambuffer length:readBytes];
}
if (CFReadStreamGetStatus(requestStream) == kCFStreamStatusError) {
error = (NSError*)CFBridgingRelease(CFReadStreamCopyError (requestStream));
if ([error code] == 61) {
// connection refused
NSLog(#"Error occured: %d",[error code]);
}
break;
}
if (CFReadStreamGetStatus(requestStream) == kCFStreamStatusAtEnd) {
NSLog(#"Stream reached end!");
error = nil;
break;
}
}//
CFHTTPMessageRef response = (CFHTTPMessageRef)CFReadStreamCopyProperty(requestStream, kCFStreamPropertyHTTPResponseHeader);
if (response==NULL) {
NSLog(#"response is null");
return;
}
}
The above was done using examples from here and here
But even the above method has the same issue. That is: if {} are not encoded the URL doesn't get generated. If the {} are encoded the server doesn't return a proper value.
Any other suggestions to resolve this posts issue?
Related
I have a text with http:// in NSString. I want to get that http link from the NSString. How can i get the link/url from the string? Eg: 'Stack over flow is very useful link for the beginners https://stackoverflow.com/'. I want to get the 'https://stackoverflow.com/' from the text. How can i do this? Thanks in advance.
I am not sure what you exactly mean by link but if you want to convert your NSString to NSURL than you can do the following:
NSString *urlString = #"http://somepage.com";
NSURL *url = [NSURL URLWithString:urlString];
EDIT
This is how to get all URLs in a given NSString:
NSString *str = #"This is a grate website http://xxx.xxx/xxx you must check it out";
NSArray *arrString = [str componentsSeparatedByString:#" "];
for(int i=0; i<arrString.count;i++){
if([[arrString objectAtIndex:i] rangeOfString:#"http://"].location != NSNotFound)
NSLog(#"%#", [arrString objectAtIndex:i]);
}
Rather than splitting the string into an array and messing about that way, you can just search for the substring beginning with #"http://":
NSString *str = #"Stack over flow is very useful link for the beginners http://stackoverflow.com/";
// get the range of the substring starting with #"http://"
NSRange rng = [str rangeOfString:#"http://" options:NSCaseInsensitiveSearch];
// Set up the NSURL variable to hold the created URL
NSURL *newURL = nil;
// Make sure that we actually have found the substring
if (rng.location == NSNotFound) {
NSLog(#"URL not found");
// newURL is initialised to nil already so nothing more to do.
} else {
// Get the substring from the start of the found substring to the end.
NSString *urlString = [str substringFromIndex:rng.location];
// Turn the string into an URL and put it into the declared variable
newURL = [NSURL URLWithString:urlString];
}
try this :
nsstring *str = #"Stack over flow is very useful link for the beginners http://stackoverflow.com/";
nsstring *http = #"http";
nsarray *arrURL = [str componentsSeparatedByString:#"http"];
this will give two objects in the nsarray. 1st object will be having:Stack over flow is very useful link for the beginners and 2nd will be : ://stackoverflow.com/ (i guess)
then you can do like:
NSString *u = [arrURL lastObject];
then do like:
nsstring *http = [http stringByAppendingFormat:#"%#",u];
Quite a lengthy,but i think that would work for you. Hope that helps you.
I have a for-loop that currently loops 4 times.
//Add all the URLs from the server to the array
for (int i = 1; i <= 5; i++){
NSString *tempString = [[NSString alloc] initWithFormat : #"http://photostiubhart.comoj.com/GalleryImages/%dstiubhart1.jpg", i];
[myURLS addObject: [NSURL URLWithString:tempString]];
[tempString release];
}
As you can see the URL has a digit in it that get incremented by 1 each loop to create a new URL where the next image will be. However, the amount of images on the server won't necessarily be 4, it could be a lot more or even less. My problem is this, is there a way I can check if there is an image stored at the URL? And if there is not, break the loop and continue program execution?
Thanks,
Jack
Here is idea to check with HTTP response
NSURLRequest *request;
NSURLResponse *response = nil;
NSError **error=nil;
NSData *data=[[NSData alloc] initWithData:[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:error]];
NSString* retVal = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
// you can use retVal , ignore if you don't need.
NSInteger httpStatus = [((NSHTTPURLResponse *)response) statusCode];
NSLog(#"responsecode:%d", httpStatus);
// there will be various HTTP response code (status)
// you might concern with 404
if(httpStatus == 404)
{
// do your job
}
or
while(httpStatus == 200){
static int increment = 0;
increment++;
// check other URL yoururl/somthing/increment++
}
but it will be slow. what my suggestion is, if you are using your own webserver, then, you can send all the image information initially. I'm sure you are doing this job on annonymous or other website :)
Let me know if it helps you or not
Here is simplest way to check if URL is valid:
NSURL *URL = [NSURL URLWithString:#"www.your.unvalidated.yet/url"];
if ( [[UIApplication sharedApplication] canOpenURL:[URL absoluteURL]] )
{
//your link is ok
}
What's an efficient way to take an NSURL object such as the following:
foo://name/12345
and break it up into one string and one unsigned integer, where the string val is 'name' and the unsigned int is 12345?
I'm assuming the algorithm involves converting NSURL to an NSString and then using some components of NSScanner to finish the rest?
I can only add an example here, the NSURL class is the one to go. This is not complete but will give you a hint on how to use NSURL:
NSString *url_ = #"foo://name.com:8080/12345;param?foo=1&baa=2#fragment";
NSURL *url = [NSURL URLWithString:url_];
NSLog(#"scheme: %#", [url scheme]);
NSLog(#"host: %#", [url host]);
NSLog(#"port: %#", [url port]);
NSLog(#"path: %#", [url path]);
NSLog(#"path components: %#", [url pathComponents]);
NSLog(#"parameterString: %#", [url parameterString]);
NSLog(#"query: %#", [url query]);
NSLog(#"fragment: %#", [url fragment]);
output:
scheme: foo
host: name.com
port: 8080
path: /12345
path components: (
"/",
12345
)
parameterString: param
query: foo=1&baa=2
fragment: fragment
This Q&A NSURL's parameterString confusion with use of ';' vs '&' is also interesting regarding URLs.
NSURL has a method pathComponents, which returns an array with all the different path components. That should help you get the integer part. To get the name I'd use the host method of the NSURL. The docs say, that it should work if the URL is properly formatted, might as well give it a try then.
All in all, no need to convert into a string, there seems to be plenty of methods to work out the components of the URL from the NSURL object itself.
Actually there is a better way to parse NSURL. Use NSURLComponents. Here is a simle example:
Swift:
extension URL {
var params: [String: String]? {
if let urlComponents = URLComponents(url: self, resolvingAgainstBaseURL: true) {
if let queryItems = urlComponents.queryItems {
var params = [String: String]()
queryItems.forEach{
params[$0.name] = $0.value
}
return params
}
}
return nil
}
}
Objective-C:
NSURLComponents *components = [NSURLComponents componentsWithURL:url resolvingAgainstBaseURL:NO];
NSArray *queryItems = [components queryItems];
NSMutableDictionary *dict = [NSMutableDictionary new];
for (NSURLQueryItem *item in queryItems)
{
[dict setObject:[item value] forKey:[item name]];
}
Thanks to Nick for pointing me in the right direction.
I wanted to compare file urls but was having problems with extra slashes making isEqualString useless. You can use my example below for comparing two urls by first de-constructing them and then comparing the parts against each other.
- (BOOL) isURLMatch:(NSString*) url1 url2:(NSString*) url2
{
NSURL *u1 = [NSURL URLWithString:url1];
NSURL *u2 = [NSURL URLWithString:url2];
if (![[u1 scheme] isEqualToString:[u2 scheme]]) return NO;
if (![[u1 host] isEqualToString:[u2 host]]) return NO;
if (![[url1 pathComponents] isEqualToArray:[url2 pathComponents]]) return NO;
//check some properties if not nil as isEqualSting fails when comparing them
if ([u1 port] && [u2 port])
{
if (![[u1 port] isEqualToNumber:[u2 port]]) return NO;
}
if ([u1 query] && [u2 query])
{
if (![[u1 query] isEqualToString:[u2 query]]) return NO;
}
return YES;
}
We are pulling content off our website using XML/NSMutableURLRequest and sometimes it pulls through the "curly" style apostrophe and quotes, ’ rather than '. NSMutableURLRequest seems to hate these and turns them into the strange \U00e2\U0080\U0099 string.
Is there something that I can to do prevent this? I am using the GET method, so should I be somehow telling it to use UTF-8? Or, am I missing something?
UIApplication* app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = YES;
NSString *urlStr = [NSString stringWithFormat:#"%#",url];
NSURL *serviceUrl = [NSURL URLWithString:urlStr];
NSMutableURLRequest *serviceRequest = [NSMutableURLRequest requestWithURL:serviceUrl];
[serviceRequest setHTTPMethod:#"GET"];
NSURLResponse *serviceResponse;
NSError *serviceError;
app.networkActivityIndicatorVisible = NO;
return [NSURLConnection sendSynchronousRequest:serviceRequest returningResponse:&serviceResponse error:&serviceError];
NSURLConnection returns an NSData response. You can take that NSData response and turn it into a string. Then take this string, turn it back into a NSData object, properly UTF-8 encoding it along the way, and feed it to NSXMLParser.
Example: (Assuming response is the NSData response from your request)
// long variable names for descriptive purposes
NSString* xmlDataAsAString = [[[NSString alloc] initWithData:response] autorelease];
NSData* toFeedToXMLParser = [xmDataAsAString dataUsingEncoding:NSUTF8StringEncoding];
NSXMLParser* parser = [[[NSXMLParser alloc] initWithData:toFeedToXMLParser] autorelease];
// now utilize parser...
I would suggest replacing those characters using stringByReplacingCharactersInRange:withString: to replace the unwanted strings.
NSString *currentTitle = #"Some string with a bunch of stuff in it.";
//Create a new range for each character.
NSRange rangeOfDash = [currentTitle rangeOfString:#"character to replace"];
NSString *location = (rangeOfDash.location != NSNotFound) ? [currentTitle substringToIndex:rangeOfDash.location] : nil;
if(location){
currentTitle = [[currentTitle stringByReplacingOccurrencesOfString:location withString:#""] mutableCopy];
}
I've done this in the past to handle the same problem you describe.
Try using the stringByReplacingPercentEscapesUsingEncoding:
I am interested in detecting the MIME-type for a file in the documents directory of my iPhone application. A search through the docs did not provide any answers.
It's a bit hacky, but it should work, don't know for sure because I'm just guessing at it
There are two options:
If you just need the MIME type, use the timeoutInterval: NSURLRequest.
If you want the data as well, you should use the commented out NSURLRequest.
Make sure to perform the request in a thread though, since it's synchronous.
NSString* filePath = [[NSBundle mainBundle] pathForResource:#"imagename" ofType:#"jpg"];
NSString* fullPath = [filePath stringByExpandingTildeInPath];
NSURL* fileUrl = [NSURL fileURLWithPath:fullPath];
//NSURLRequest* fileUrlRequest = [[NSURLRequest alloc] initWithURL:fileUrl];
NSURLRequest* fileUrlRequest = [[NSURLRequest alloc] initWithURL:fileUrl cachePolicy:NSURLCacheStorageNotAllowed timeoutInterval:.1];
NSError* error = nil;
NSURLResponse* response = nil;
NSData* fileData = [NSURLConnection sendSynchronousRequest:fileUrlRequest returningResponse:&response error:&error];
fileData; // Ignore this if you're using the timeoutInterval
// request, since the data will be truncated.
NSString* mimeType = [response MIMEType];
[fileUrlRequest release];
Add MobileCoreServices framework.
Objective C:
#import <MobileCoreServices/MobileCoreServices.h>
NSString *fileExtension = [myFileURL pathExtension];
NSString *UTI = (__bridge_transfer NSString *)UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, (__bridge CFStringRef)fileExtension, NULL);
NSString *contentType = (__bridge_transfer NSString *)UTTypeCopyPreferredTagWithClass((__bridge CFStringRef)UTI, kUTTagClassMIMEType);
Swift:
import MobileCoreServices
func mimeType(fileExtension: String) -> String? {
guard !fileExtension.isEmpty else { return nil }
if let utiRef = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, fileExtension as CFString, nil) {
let uti = utiRef.takeUnretainedValue()
utiRef.release()
if let mimeTypeRef = UTTypeCopyPreferredTagWithClass(UTI, kUTTagClassMIMEType) {
let mimeType = MIMETypeRef.takeUnretainedValue()
mimeTypeRef.release()
return mimeType as String
}
}
return nil
}
The accepted answer is problematic for large files, as others have mentioned. My app deals with video files, and loading an entire video file into memory is a good way to make iOS run out of memory. A better way to do this can be found here:
https://stackoverflow.com/a/5998683/1864774
Code from above link:
+ (NSString*) mimeTypeForFileAtPath: (NSString *) path {
if (![[NSFileManager defaultManager] fileExistsAtPath:path]) {
return nil;
}
// Borrowed from https://stackoverflow.com/questions/5996797/determine-mime-type-of-nsdata-loaded-from-a-file
// itself, derived from https://stackoverflow.com/questions/2439020/wheres-the-iphone-mime-type-database
CFStringRef UTI = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, (CFStringRef)[path pathExtension], NULL);
CFStringRef mimeType = UTTypeCopyPreferredTagWithClass (UTI, kUTTagClassMIMEType);
CFRelease(UTI);
if (!mimeType) {
return #"application/octet-stream";
}
return [NSMakeCollectable((NSString *)mimeType) autorelease];
}
Prcela solution did not work in Swift 2. The following simplified function will return the mime-type for a given file extension in Swift 2:
import MobileCoreServices
func mimeTypeFromFileExtension(fileExtension: String) -> String? {
guard let uti: CFString = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, fileExtension as NSString, nil)?.takeRetainedValue() else {
return nil
}
guard let mimeType: CFString = UTTypeCopyPreferredTagWithClass(uti, kUTTagClassMIMEType)?.takeRetainedValue() else {
return nil
}
return mimeType as String
}
I was using the answer provided by slf in a cocoa app (not iPhone) and noticed that the URL request seems to be reading the entire file from disk in order to determine the mime type (not great for large files).
For anyone wanting to do this on the desktop here is the snippet I used (based on Louis's suggestion):
NSString *path = #"/path/to/some/file";
NSTask *task = [[[NSTask alloc] init] autorelease];
[task setLaunchPath: #"/usr/bin/file"];
[task setArguments: [NSArray arrayWithObjects: #"-b", #"--mime-type", path, nil]];
NSPipe *pipe = [NSPipe pipe];
[task setStandardOutput: pipe];
NSFileHandle *file = [pipe fileHandleForReading];
[task launch];
[task waitUntilExit];
if ([task terminationStatus] == YES) {
NSData *data = [file readDataToEndOfFile];
return [[[NSString alloc] initWithData: data encoding: NSUTF8StringEncoding] autorelease];
} else {
return nil;
}
If you called that on a PDF file it would spit out: application/pdf
Based on the Lawrence Dol/slf answer above, I have solved the NSURL loading the entire file into memory issue by chopping the first few bytes into a head-stub and getting the MIMEType of that. I have not benchmarked it, but it's probably faster this way too.
+ (NSString*) mimeTypeForFileAtPath: (NSString *) path {
// NSURL will read the entire file and may exceed available memory if the file is large enough. Therefore, we will write the first fiew bytes of the file to a head-stub for NSURL to get the MIMEType from.
NSFileHandle *readFileHandle = [NSFileHandle fileHandleForReadingAtPath:path];
NSData *fileHead = [readFileHandle readDataOfLength:100]; // we probably only need 2 bytes. we'll get the first 100 instead.
NSString *tempPath = [NSHomeDirectory() stringByAppendingPathComponent: #"tmp/fileHead.tmp"];
[[NSFileManager defaultManager] removeItemAtPath:tempPath error:nil]; // delete any existing version of fileHead.tmp
if ([fileHead writeToFile:tempPath atomically:YES])
{
NSURL* fileUrl = [NSURL fileURLWithPath:path];
NSURLRequest* fileUrlRequest = [[NSURLRequest alloc] initWithURL:fileUrl cachePolicy:NSURLCacheStorageNotAllowed timeoutInterval:.1];
NSError* error = nil;
NSURLResponse* response = nil;
[NSURLConnection sendSynchronousRequest:fileUrlRequest returningResponse:&response error:&error];
[[NSFileManager defaultManager] removeItemAtPath:tempPath error:nil];
return [response MIMEType];
}
return nil;
}
On Mac OS X this would be handled through LaunchServices and UTIs. On the iPhone these are not available. Since the only way for data to get into your sandbox is for you to put it there, most apps have intrinsic knowledge about the data of any file they can read.
If you have a need for such a feature you should file a feature request with Apple.
I'm not sure what are the practices on iPhone, but if you're allowed to, I'd make use of UNIX philosophy here: use program file, which is the standard way to detect filetype on an UNIX operating system. It includes a vast database of magic markers for filetype detection. Since file is probably not shipped on iPhone, you could include it in your app bundle. There might be a library implementing file's functionality.
Alternatively, you could trust the browser. Browsers send the MIME type they guessed somewhere in the HTTP headers. I know that I can easily grab the MIME type information in PHP. That of course depends if you're willing to trust the client.
Make sure are you import the coreservices
import <CoreServices/CoreServices.h>
in your file.