I have tried (searching for) various possible solutions here on SO, in vain. Most of them simply replace all occurrences of backslashes, and don't respect backslashes that should otherwise be untouched.
For instance, if I have a Hi, it\'s me. How\'re you doing?, it should be Hi, it's me. How're you doing?. However, if someone tries to get creative with ASCII art, like
\\// \\// \\//
//\\ //\\ //\\
(WOW even SO won't let me add text as is, the above text needed extra backslashes to be displayed correctly.)
I cannot use [myString stringByReplacingOccurrencesOfString:#"\\" withString:#""]; since it will replace ALL backslashes. I do not want that.
I would like the string to be displayed as is.
NOTE: The strings in question here are values in NSDictionarys received as JSON from a web service. The use is in a service like a chat client, so it is important that text is handled correctly.
ULTRA IMPORTANT NOTE: I'm open to all ideas like library functions, regular expressions, human sacrifices, as long it gets the job done.
try this ...i cannot understand your question but it may help full for you,i think so
- (void)remove:(NSString*)str
{
NSString* const pattern = #"(\"[^\"]*\"|[^, ]+)";
NSRegularExpression *regex = [[NSRegularExpression alloc] initWithPattern:pattern
options:0
error:nil];
NSRange searchRange = NSMakeRange(0, [str length]);
NSArray *matches = [regex matchesInString:str
options:0
range:searchRange];
for (NSTextCheckingResult *match in matches) {
NSRange matchRange = [match range];
NSLog(#"%#", [str substringWithRange:matchRange]);
}
NSLog(#"%#",str);
}
call this method..
NSString* str = #"Hi, it\'s me. How\'re you doing?";
[self remove:str];
then the output is
Hi, it's me. How're you doing?
Related
First off, I have no control over the text I am getting. Just wanted to put that out there so you know that I can't change the links.
The text I am trying to find links in using NSDataDetector contains the following:
<h1>My main item</h1>
<img src="http://www.blah.com/My First Image Here.jpg">
<h2>Some extra data</h2>
The detection code I am using is this, but it will not find this link:
NSDataDetector *linkDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:nil];
NSArray *matches = [linkDetector matchesInString:myHTML options:0 range:NSMakeRange(0, [myHTML length])];
for (NSTextCheckingResult *match in matches)
{
if ([match resultType] == NSTextCheckingTypeLink)
{
NSURL *url = [match URL];
// does some stuff
}
}
Is this a bug with Apple's link detection here, where it can't detect links with spaces, or am I doing something wrong?
Does anyone have a more reliable way to detect links regardless of whether they have spaces or special characters or whatever in them?
I just got this response from Apple for a bug I filed on this:
We believe this issue has been addressed in the latest iOS 9 beta.
This is a pre-release iOS 9 update.
Please refer to the release notes for complete installation
instructions.
Please test with this release. If you still have issues, please
provide any relevant logs or information that could help us
investigate.
iOS 9 https://developer.apple.com/ios/download/
I will test and let you all know if this is fixed with iOS 9.
You could split the strings into pieces using the spaces so that you have an array of strings with no spaces. Then you could feed each of those strings into your data detector.
// assume str = <img src="http://www.blah.com/My First Image Here.jpg">
NSArray *components = [str componentsSeparatedByString:#" "];
for (NSString *strWithNoSpace in components) {
// feed strings into data detector
}
Another alternative is to look specifically for that HTML tag. This is a less generic solution, though.
// assume that those 3 HTML strings are in a string array called strArray
for (NSString *htmlLine in strArray) {
if ([[htmlLine substringWithRange:NSMakeRange(0, 8)] isEqualToString:#"<img src"]) {
// Get the url from the img src tag
NSString *urlString = [htmlLine substringWithRange:NSMakeRange(10, htmlLine.length - 12)];
}
}
I've found a very hacky way to solve my issue. If someone comes up with a better solution that can be applied to all URLs, please do so.
Because I only care about URLs ending in .jpg that have this problem, I was able to come up with a narrow way to track this down.
Essentially, I break out the string into components based off of them beginning with "http:// into an array. Then I loop through that array doing another break out looking for .jpg">. The count of the inner array will only be > 1 when the .jpg"> string is found. I then keep both the string I find, and the string I fix with %20 replacements, and use them to do a final string replacement on the original string.
It's not perfect and probably inefficient, but it gets the job done for what I need.
- (NSString *)replaceSpacesInJpegURLs:(NSString *)htmlString
{
NSString *newString = htmlString;
NSArray *array = [htmlString componentsSeparatedByString:#"\"http://"];
for (NSString *str in array)
{
NSArray *array2 = [str componentsSeparatedByString:#".jpg\""];
if ([array2 count] > 1)
{
NSString *stringToFix = [array2 objectAtIndex:0];
NSString *fixedString = [stringToFix stringByReplacingOccurrencesOfString:#" " withString:#"%20"];
newString = [newString stringByReplacingOccurrencesOfString:stringToFix withString:fixedString];
}
}
return newString;
}
You can use NSRegularExpression to fix all URLs by using a simple regex to detect the links and then just encode the spaces (if you need more complex encoding you can look into CFURLCreateStringByAddingPercentEscapes and there are plenty of examples out there). The only thing that might take you some time if you haven't worked with NSRegularExpression before is how to iterate the results and do the replacing, the following code should do the trick:
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"src=\".*\"" options:NSRegularExpressionCaseInsensitive error:&error];
if (!error)
{
NSInteger offset = 0;
NSArray *matches = [regex matchesInString:myHTML options:0 range:NSMakeRange(0, [myHTML length])];
for (NSTextCheckingResult *result in matches)
{
NSRange resultRange = [result range];
resultRange.location += offset;
NSString *match = [regex replacementStringForResult:result inString:myHTML offset:offset template:#"$0"];
NSString *replacement = [match stringByReplacingOccurrencesOfString:#" " withString:#"%20"];
myHTML = [myHTML stringByReplacingCharactersInRange:resultRange withString:replacement];
offset += ([replacement length] - resultRange.length);
}
}
Try this regex pattern: #"<img[^>]+src=(\"|')([^\"']+)(\"|')[^>]*>" with ignore case ... Match index=2 for source url.
regex demo in javascript: (Try for any help)
Demo
Give this snippet a try (I got the regexp from your first commentator user3584460) :
NSError *error = NULL;
NSString *myHTML = #"<http><h1>My main item</h1><img src=\"http://www.blah.com/My First Image Here.jpg\"><h2>Some extra data</h2><img src=\"http://www.bloh.com/My Second Image Here.jpg\"><h3>Some extra data</h3><img src=\"http://www.bluh.com/My Third-Image Here.jpg\"></http>";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"src=[\"'](.+?)[\"'].*?>" options:NSRegularExpressionCaseInsensitive error:&error];
NSArray *arrayOfAllMatches = [regex matchesInString:myHTML options:0 range:NSMakeRange(0, [myHTML length])];
NSTextCheckingResult *match = [regex firstMatchInString:myHTML options:0 range:NSMakeRange(0, myHTML.length)];
for (NSTextCheckingResult *match in arrayOfAllMatches) {
NSRange range = [match rangeAtIndex:1];
NSString* substringForMatch = [myHTML substringWithRange:range];
NSLog(#"Extracted URL : %#",substringForMatch);
}
In my log, I have :
Extracted URL : http://www.blah.com/My First Image Here.jpg
Extracted URL : http://www.bloh.com/My Second Image Here.jpg
Extracted URL : http://www.bluh.com/My Third-Image Here.jpg
You should not use NSDataDetector with HTML. It is intended for parsing normal text (entered by an user), not computer-generated data (in fact, it has many heuristics to actually make sure it does not detect computer-generated things which are probably not relevant to the user).
If your string is HTML, then you should use an HTML parsing library. There are a number of open-source kits to help you do that. Then just grab the href attributes of your anchors, or run NSDataDetector on the text nodes to find things not marked up without polluting the string with tags.
URLs really shouldn't contain spaces. I'd remove all spaces from the string before doing anything URL-related with it, something like the following
// Custom function which cleans up strings ready to be used for URLs
func cleanStringForURL(string: NSString) -> NSString {
var temp = string
var clean = string.stringByReplacingOccurrencesOfString(" ", withString: "")
return clean
}
My app puts a space after the ":" in case the user forgets to. Like so:
input = [input stringByReplacingOccurrencesOfString:#":" withString:#": "];
This works well if they type in English. It will make "My friends are:James.." into "My friends are: James..." and this is fine.
BUT the problem I'm having is it also ads a space within a time. It will make "12:30" into "12: 30". I could make a bunch of these codes with all the number possibilities to fix, which is too much.
input = [input stringByReplacingOccurrencesOfString:#": 0" withString:#":0"];
What is the easier way to do this? I've tried:
input = [input stringByReplacingOccurrencesOfString:#"\\b\\d\\d?:\\s\\d\\d\\b" withString:#"\\b\\d\\d?:\\d\\d\\b" options: NSRegularExpressionSearch range:NSMakeRange(0, [input length])];
But all that does is change ALL times from "hh: mm" to "bdd?:ddb" and that's it. how do I make an NSString replacement retain it's previous characters? Like how can I make it still keep the same numbers that were previously put? All I want to change is the ": " to be ":" in a time.
I've tried "if" statements with NSNotFound but it wasn't working. I wanted it that if it found a "hh:mm" format, to NOT add a space, but if it didn't, to add a space but that didn't work.
You were on the right lines with the last version, but you need to use NSRegularExpression. The following should do the whole thing for you (adding spaces after colons, but not when sandwiched between double digits or already followed by a space):
NSString *input = #"My friends are:James, John. It's 10:30 right now.";
NSMutableString *workingString = [input mutableCopy];
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"(((?<!(\\b\\d\\d)):)|(:(?!(\\d\\d\\b))))(?!\\s)" options:0 error:nil];
[regex replaceMatchesInString:workingString options:0 range:NSMakeRange(0, [workingString length]) withTemplate:#": "];
input = [workingString copy];
NSLog(#"%#", input); // Prints "My friends are: James, John. It's 10:30 right now."
You can do it in this way..If you have either time in string or only sentence with no numbers...
NSCharacterSet *s = [NSCharacterSet characterSetWithCharactersInString:#"1234567890"];
NSRange r = [input rangeOfCharacterFromSet:s];
if (r.location != NSNotFound)
{
input = [input stringByReplacingOccurrencesOfString:#":" withString:#": "];
}
Hope it helps you..
I have a VERY long NSString. It contains about 100 strings I need to pull out of it, all randomly scattered throughout. They are all commonly are between imgurl= and &.
I could use NSRange and just loop through pulling out each string, but I'm wondering if there is a quicker was to pick out everything in a simple API call? Maybe something I am missing here?
Looking for the quickest way to do this. Thanks!
Using NSString methods componentsSeparatedByString and componentsSeparatedByCharactersInSet:
NSString *longString = some really long string;
NSArray *longStringComponents = [longString componentsSeparatedByString:#"imgurl="];
for (NSString *string in longStringComponents){
NSString *imgURLString = [[string componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:#"&"]] firstObject];
// do something with imgURLString...
}
If you feel adventurous then you can use regular expression. Since you said that the string you are looking is between imgurl and &, I assumed its a url and made the sample code to do the same.
NSString *str = #"http://www.example.com/image?imgurl=my_image_url1&imgurl=myimageurl2&somerandom=blah&imgurl=myurl3&someother=lol";
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"(?:imageurl=)(.*?)(?:&|\\r)"
options:NSRegularExpressionCaseInsensitive
error:&error];
//should do error checking here...
NSArray *matches = [regex matchesInString:str
options:0
range:NSMakeRange(0, [str length])];
for (NSTextCheckingResult *match in matches)
{
//[match rangeAtIndex:0] <- gives u the whole string matched.
//[match rangeAtIndex:1] <- gives u the first group you really care about.
NSLog(#"%#", [str substringWithRange:[match rangeAtIndex:1]]);
}
If I were you, I will still go with #bobnoble method because its easier and simpler compared to regex. You will have to do more error checking using this method.
I am trying to get the following regex to work on ios in order to make sure the user is only inputting numbers and a dot. I am not able to get number of matches to be above 0. I have also tried NSRange one as well and that will give me 0 no matter what as well, so my regex is not working, even thought I am pretty sure it should with what I have there. Any suggestions.
The Code I wrote is here with errorRegex is defined in the .h file and regError is defined as well.
errorRegex = [NSRegularExpression regularExpressionWithPattern:#"[^0-9.]*"
options: NSRegularExpressionCaseInsensitive error:®Error];
NSUInteger rangeOfFirstMatch = [errorRegex numberOfMatchesInString:servAmount1TF.text
options:0 range:NSMakeRange(0, [servAmount1TF.text length])];
Why not use stock-standard c's regex.h ?
See an example here:
http://cboard.cprogramming.com/c-programming/117525-regex-h-extracting-matches.html
And more information here:
https://stackoverflow.com/a/422159/1208218
errorRegex is of type NSRegularExpression, but the error is of type UIButtonContent. This has all the halmarks of a memory error. Something in your code not going though a proper retain/release cycle.
I got a unit test to work with the expression #"[^0-9.]+"
- (void)testRE
{
NSError *regError = nil;
NSRegularExpression *errorRegex;
NSString *string;
NSUInteger count;
errorRegex = [NSRegularExpression regularExpressionWithPattern:#"[^0-9.]+"
options: NSRegularExpressionCaseInsensitive
error:®Error];
STAssertNil(regError, nil);
string = #"00.0";
count = [errorRegex numberOfMatchesInString:string
options:0
range:NSMakeRange(0, [string length])];
STAssertEquals(count, 0U, nil);
string = #"00A00";
count = [errorRegex numberOfMatchesInString:string
options:0
range:NSMakeRange(0, [string length])];
STAssertEquals(count, 1U, nil);
}
NSRegularExpression *errorCheckRegEx = [[NSRegularExpression alloc] initWithPattern:#"\\b^([0-9]+(\\.)?[0-9]*)$|^([0-9]*(\\.)?[0-9]+)$|^[0-9]*$|^([0-9]*(\\/)?[0-9]*)$\\b" options:NSRegularExpressionCaseInsensitive error:nil];
[match setArray: [errorCheckRegEx matchesInString:servAmount1TF.text options:0 range:NSMakeRange(0, [servAmount1TF.text length])]];
I figured out what I needed to do when I could finally get back to it so if anyone was interested this is what I came up with. The \b is just what ios uses in their regexp which is kind of dumb, but it will not work without that so I leave it there when it doesn't feel natural to do especially after ruby's example. This regular expression will get fractions, decimals -> .3; 2.3; 2; and does it from the front to end of the line. What I think might have been happening was the fact that I was not using the \b and also not matching correctly, which is the second line. Either way it works great now. Thanks for the help.
Say I have a string that contains a control code "\f3" (yes it is RTF). I want to replace that control code with another string. At the moment I am using [mutableString replaceOccurrencesOfString:#"\f3" withString:#"replacement string" options:0 range:NSMakeRange(0, [mutableString length])];
This works fine, however sometimes the code can be "\f4" or even "\f12" for example. How do I replace these strings? I could use replaceOccurrencesOfString for each, but the better way to do it is using wildcards, as it could be any number.
Regular expressions would do it.
Take a look at NSRegularExpression (iOS >= 4) and this page for how regular expressions work.
You will want something like:
// Create your expression
NSError *error = nil;
NSRegularExpression *regex =
[NSRegularExpression regularExpressionWithPattern:#"\\b\f[0-9]*\\b"
options:NSRegularExpressionCaseInsensitive
error:&error];
// Replace the matches
NSString *modifiedString = [regex stringByReplacingMatchesInString:string
options:0
range:NSMakeRange(0, [string length])
withTemplate:#"replacement string"];
WARNING : I've not tested my regaular expression and I'm not that great at getting them right first time; I just know that regular expressions are the way forward for you and it has to look something like that ;)