When you have a filesystem path, you can have a ".." removed (and the previous path component removed as well) by using the stringByResolvingSymlinksInPath selector. How can I achieve the same thing for a URL? For example I start out with, say:
www.example.com/themes/themeA/../common/assetA.png
Which I need converted to:
www.example.com/themes/common/assetA.png
For a URL use the NSURL method:
- (NSURL *)standardizedURL
Returns a new URL that points to the same resource as the original URL and is an absolute path.
Example:
NSString *s = #"www.example.com/themes/themeA/../common/assetA.png";
NSURL *u = [NSURL URLWithString:s];
NSURL *su = [u standardizedURL];
NSLog(#"su: %#", su);
NSLog output:
su: www.example.com/themes/common/assetA.png
What about the following?
NSString* resolved_url
= [[[NSURL URLWithString: #"www.example.com/themes/themeA/../common/assetA.png"] standardizedURL] absoluteString];
If you want NSURL instead of NSString, remove call to absoluteString.
Related
I'm trying to convert a NSString (a path to a file in the documents directory) to a NSURL, but the NSURL is always null. Here is my code:
NSURL *urlToPDF = [NSURL URLWithString:appDelegate.pdfString];
NSLog(#"AD: %#", appDelegate.pdfString);
NSLog(#"PDF: %#", urlToPDF);
pdf = CGPDFDocumentCreateWithURL((CFURLRef)urlToPDF);
And here is the log:
2012-03-20 18:31:49.074 The Record[1496:15503] AD: /Users/John/Library/Application Support/iPhone Simulator/5.1/Applications/E1F20602-0658-464D-8DDC-52A842CD8146/Documents/issues/3.1.12/March 1, 2012.pdf
2012-03-20 18:31:49.074 The Record[1496:15503] PDF: (null)
I think part of the problem might be that the NSString contains slashes / and dashes -. What am I doing incorrectly? Thanks.
Why don't you create your file path in this way which is.
NSString *filePath = [[NSBundle mainBundle]pathForResource:#"pdfName" ofType:#"pdf"];
And then create your url with file path like this.
NSURL *url = [NSURL fileURLWithPath:filePath];
The thing is, appDelegate.pdfString isn't a valid URL, it's a path. A file URL looks like:
file://host/path
or for the local host:
file:///path
So you actually want:
NSURL *urlToPDF = [NSURL URLWithString:[NSString stringWithFormat:#"file:///%#", appDelegate.pdfString]];
...except your path has spaces, which need to be URL encoded, so you actually want:
NSURL *urlToPDF = [NSURL URLWithString:[NSString stringWithFormat:#"file:///%#", [appDelegate.pdfString stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]]];
I have an NSString containing a url and when I allocate NSURL with the NSString, NSURL outputs (null). It's because there are some illegal characters in the url, which NSURL can't read without encoding the NSString containing the url.
NSString *u = [incomingUrlString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:u];
NSLog(#"INCOMINGURLSTRING: %#" , u);
NSLog(#"URL: %#" , url);
Output is:
INCOMINGURLSTRING: /url/path/fileName_blå.pdf
URL: (null)
incomingUrlString contains the Norwegian letter "å", which I think is the reason for the NSURL being (null)
I also tried this:
NSString *trimmedString = [file stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
NSString *encodedString = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef)trimmedString, NULL, (CFStringRef)#"!*'\"();:#&=+$,/?%#[]% ", kCFStringEncodingUTF8);
NSLog(#"TRIMMEDSTRING: %#" , trimmedString);
NSLog(#"ENCODEDSTRING: %#" , [encodedString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding]);
NSURL *url = [NSURL URLWithString:encodedString];
NSLog(#"URL: %#" , url);
Here the output is:
TRIMMEDSTRING: /url/path/fileName_blå.pdf
ENCODEDSTRING: /url/path/fileName_blå.pdf
URL: %2Furl%2FPath%2FfileName_bl%C3%A5.pdf
My goal is to load the URL into a UIWebView. It works for all the other incoming urls except for this one, they all look the same except for the filename. This is the only one containg an illegal character. But I have to find a way to encode this, because there will be more files containg either "æ", "ø" or "å" in the future.
I know the output does not look correct according to url standards, which I did on purpose. I can't show the correct url with http://blah blah because of security reasons.
Can anyone help?
The method you're using for percent-encoding the characters in the string also escapes legal URL characters. This would be appropriate if you were encoding a URL parameter, in this case though it would be better to simply use stringByAddingPercentEscapesUsingEncoding: because it leaves the characters that are part of the URL's structure (':', '/', etc.) intact:
NSString *u = #"http://example/path/fileName_blå.pdf";
u = [u stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:u];
NSLog(#"%#", url); // http://example.com/path/fileName_bl%C3%A5.pdf
If you have an URL that is a file path you must use + (id)fileURLWithPath:(NSString *)path. For the URLWithString: method the String must contain a scheme like file:// or http://.
stringByAddingPercentEscapesUsingEncoding is deprecated.
The new way (iOS 7+) to do it is:
NSString *encoded = [raw stringByAddingPercentEncodingWithAllowedCharacters:NSCharacterSet.URLPathAllowedCharacterSet];
File path is defined by https://www.rfc-editor.org/rfc/rfc8089.
The key part is to allow characters . and / and disallow %. CharacterSet.urlPathAllowed fits the requirements.
Output with your example:
incomingString: /url/path/fileName_blå.pdf
encodedString: /url/path/fileName_bl%C3%A5.pdf
URL: /url/path/fileName_bl%C3%A5.pdf
I found also that for some North European characters, NSISOLatin1StringEncoding fits better.
- (void) testEncoding {
NSString * urlString = #"http://example/path/fileName_blå.pdf";
urlString = [urlString stringByAddingPercentEscapesUsingEncoding:NSISOLatin1StringEncoding];
NSURL * url = [NSURL URLWithString:urlString];
NSLog(#"URL: %#", url);
}
Trying to convert a string to NSURL and this is not happening.
barcodeTextLabel.text = foundCode.barcodeString;
urlToGrab = [NSString stringWithFormat:#"%#", foundCode.barcodeString]; // foundCode.barcodeString is an NSString
urlToGrab shows the following "error invalid CFStringRef"
This is how you create an NSURL from an NSString:
NSURL *url = [NSURL URLWithString:#"http://www.google.com"];
You can use following for creating the file path to url.
NSURL *yourURL = [NSURL fileURLWithPath:#"/Users/xyz/Desktop/abc.sqlite"];
If foundCode.barcodeString is the string you want as your URL, then (like the above answer) use the NSURL class method URLWithString:(NSString *).
Your code should look like:
NSURL urlToGrab = [NSURL URLWithString:foundCode.barcodeString];
Where is your error coming into to play? The way your code is, urlToGrab is an instance of NSString. I would imagine you would get an error like you described if you tried to make an HTTP request on an NSString rather than NSURL.
Swapnali patil's answer works, but I will add an explanation.
You will get a nil if the format of NSString doesn't fit file criteria for NSURL (file:///xxx/file.ext).
My needs were with loading a JPG image via URL file path to nsdata; NSURL * u=[[NSURL alloc] initWithString:fpath] returned nil, but NSURL *yourURL = [NSURL fileURLWithPath:fpath] as in mentioned answer worked. A URL for files will be file:///users/xxx/pic.jpg format and give disk access. NSURL * u=[[NSURL alloc] initWithString:(NSString*) ] will also give nil object if nsstring is web URL but if missing http://
I have problem with NSURL. I am trying to create NSURL with string
code
NSString *prefix = (#"tel://1234567890 ext. 101");
NSString *dialThis = [NSString stringWithFormat:#"%#", prefix];
NSURL *url = [[NSURL alloc] initWithString:dialThis];
NSLog(#"%#",url);
also tried
NSURL *url = [NSURL URLWithString:dialThis];
but it gives null . what is wrong ?
Thanks..
Your problem is the unescaped spaces in the URL. This, for instance, works:
NSURL *url = [NSURL URLWithString:#"tel://1234567890x101"];
Edit: As does this..
NSURL *url2 = [NSURL URLWithString:[#"tel://1234567890 ext. 101"
stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
Before passing any string as URL you don't control, you have to encode the whitespace:
NSString *dialThis = [prefix stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
// tel://1234567890%20ext.%20101
As a side note, iOS is not going to dial any extension. The user will have to do that manually.
From Apple URL Scheme Reference: Phone Links:
To prevent users from maliciously redirecting phone calls or changing the behavior of a phone or account, the Phone application supports most, but not all, of the special characters in the tel scheme. Specifically, if a URL contains the * or # characters, the Phone application does not attempt to dial the corresponding phone number.
Im not sure the "ext." in phone number can be replce by what value? but you can try like this,
NSString *prefix = [NSString stringWithString: #"tel://1234567890 ext. 101"];
NSString *dialThis = [NSString stringWithFormat:#"%#", prefix];
NSURL *url = [NSURL URLWithString:[dialThis stringByReplacingOccurrencesOfString:#" ext. " withString:#"#"]];
// it might also represent by the pause symbol ','.
you can go to find the ext. is equivalent to what symbol in the phone, then replace it.
but dunno it can be work in actual situation or not....
As with iOS 9.0,
stringByAddingPercentEscapesUsingEncoding:
has been deprecated.
Use the following method for converting String to NSURL.
let URL = "URL GOES HERE"
let urlString = URL.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLFragmentAllowedCharacterSet())
If you've got something you think should be a URL string but know nothing about how URL strings are supposed to be constructed, you can use NSURL's URLWithDataRepresentation:relativeToURL: method. It parses the URL string (as bytes in an NSData) and percent-encodes characters as needed. Use the NSUTF8StringEncoding for best results when converting your NSString to NSData.
NSURL *url = [NSURL URLWithDataRepresentation:[#"tel:1234567890 ext. 101" dataUsingEncoding:NSUTF8StringEncoding] relativeToURL:nil];
NSLog(#"%#",url);
creates a URL with the string 1234567890%20ext.%20101
It attempts to do the right thing. However, for best results you should find the specification for the URL scheme you using and follow it's syntax to create your URL string. For the tel scheme, that is https://www.rfc-editor.org/rfc/rfc3966.
P.S. You had "tel://" instead of "tel:" which is incorrect for a tel URL.
Try this one, It works for me....
NSString *prefix = (#"tel://1234567890 ext. 101");
NSString *dialThis = [NSString stringWithFormat:#"%#", prefix];
NSURL *url = [NSURL URLWithString:[queryString stringByReplacingOccurrencesOfString:#" " withString:#"%20"]];
NSLog(#"%#",url);
Make an extension for use in any part of the project as well:
extension String {
var asNSURL: NSURL! {
return NSURL(string: self)
}
}
From now you can use
let myString = "http://www.example.com".asNSURL
or
myString.asNSURL
another issue where I seem to have found an solution for ObjC but not MonoTouch.
I want a NSUrl from an URL (as string).
The string may contain whitespace and backslashes.
Why is NSUrl returning null for such string, even though these are valid urls in a browser?
For example:
NSUrl foo = NSUrl.FromString(#"http://google.com/search?\query");
foo == null
Any suggestions?
[NSURL URLWithString:[googlSearchString stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding]];
Referenced by
Stack Overflow....
You probably need to process the string first with
stringByAddingPercentEscapesUsingEncoding:
... so that it can be processed a valid URL.
URLWithString:
Creates and returns an NSURL object initialized with a provided string.
(id)URLWithString:(NSString *)URLString
Parameters
URLString
The string with which to initialize the NSURL object. Must be a URL that conforms to RFC 2396. This method parses URLString according to RFCs 1738 and 1808. (To create NSURL objects for file system paths, use fileURLWithPath:isDirectory: instead.)
Return Value
An NSURL object initialized with URLString. If the string was malformed, returns nil.
NSString * urlString = #"http://example/newcase/path/fileNames";
urlString = [urlString stringByAddingPercentEscapesUsingEncoding:NSISOLatin1StringEncoding];
NSURL * url = [NSURL URLWithString:urlString];
NSLog(#"URL: %#", url);