I am trying to find the range of specific substrings of a string. Each substring begins with a hashtag and can have any character it likes within it (including emojis). Duplicate hashtags should be detected at distinct ranges. A kind user from here suggested this code:
var str = "The range of #hashtag should be different to this #hashtag"
let regex = try NSRegularExpression(pattern: "(#[A-Za-z0-9]*)", options: [])
let matches = regex.matchesInString(str, options:[], range:NSMakeRange(0, str.characters.count))
for match in matches {
print("match = \(match.range)")
}
However, this code does not work for emojis. What would be the regex expression to include emojis? Is there a way to detect a #, followed by any character up until a space/line break?
Similarly as in Swift extract regex matches,
you have to pass an NSRange to the match functions, and the
returned ranges are NSRanges as well. This can be achieved
by converting the given text to an NSString.
The #\S+ pattern matches a # followed by one or more
non-whitespace characters.
let text = "The 😀range of #hashtag🐶 should 👺 be 🇩🇪 different to this #hashtag🐮"
let nsText = text as NSString
let regex = try NSRegularExpression(pattern: "#\\S+", options: [])
for match in regex.matchesInString(text, options: [], range: NSRange(location: 0, length: nsText.length)) {
print(match.range)
print(nsText.substringWithRange(match.range))
}
Output:
(15,10)
#hashtag🐶
(62,10)
#hashtag🐮
You can also convert between NSRange and Range<String.Index>
using the methods from NSRange to Range<String.Index>.
Remark: As #WiktorStribiżew correctly noticed, the above pattern
will include trailing punctuation (commas, periods, etc). If
that is not desired then
let regex = try NSRegularExpression(pattern: "#[^[:punct:][:space:]]+", options: [])
would be an alternative.
Related
I have some Arabic text which has some decimals as well.
for example this text
"بِسۡمِ اللّٰہِ الرَّحۡمٰنِ الرَّحِیۡمِ ﴿۱﴾"
"وَاِذَا قِیۡلَ لَہُمۡ اٰمِنُوۡا کَمَاۤ اٰمَنَ النَّاسُ قَالُوۡۤا اَنُؤۡمِنُ کَمَاۤ اٰمَنَ السُّفَہَآءُ ؕ اَلَاۤ اِنَّہُمۡ ہُمُ السُّفَہَآءُ وَلٰکِنۡ لَّا یَعۡلَمُوۡنَ ﴿۱۴﴾"
This text has verse numbers as Arabic digits in the end.
I wanted to find out all the matches for the verse numbers in these verses.
In swift I am tring to use the regular expression but somehow i am not coming up with the correct regex.
Here is my code:
func getRegex() {
// unicode for the arabic digits
let regexStr = "[\u{0660}-\u{0669}]+"
//let regexStr = "[\\p{N}]+"
//let regexStr = "[۹۸۷۶۵۴۳۲۱۰]+"
do {
let regex = try NSRegularExpression(pattern: regexStr, options: .caseInsensitive)
let matches = regex.matches(in: self.arabicText, options: .anchored, range: NSRange(location: 0, length: self.arabicText.count))
print("Matches count : \(matches.count)")
} catch {
print(error)
}
}
Can somebody guide me on how I can get the matches for the Arabic digits in the example Arabic text?
The .anchored argument makes the pattern only match at the start of string, so you need to remove it.
Also, as your string is not ASCII, you need to use self.arabicText.utf16.count string property rather than accessing the self.arabicText.count directly.
So, you can use
let regexStr = "[۹۸۷۶۵۴۳۲۱۰]+"
and then
let matches = regex.matches(in: self.arabicText, options: [], range: NSRange(location: 0, length: self.arabicText.utf16.count))
In my case, I need to Implement Regex for my UITextField. Here, my textfield should allow only uppercase with number mixed values.
For Example:
AI1234
ER3456
I used below one, but not working
^[A-Z0-9]{3}?$
This regex matches the pattern above
2 Uppercase characters followed by 4 numbers
^[A-Z]{2}\\d{4}
You can test it on https://regexr.com/
Edit:
let str = """
AI1234
ER3456
"""
let pattern = try? NSRegularExpression(pattern: "[A-Z]{2}\\d{4}", options: [])
let range = NSRange(location: 0, length: str.utf16.count)
let matches = pattern?.matches(in: str, options: [], range: range)
print(matches)
I had written a regex for matching cell addresses like in a spreadsheet and tried to match input strings using NSRegularExpression's matches(in string:, options:, range:) method.
let input = "A:IV"
let regexStr = "(\\$?(([a-h]?[a-z])|i[a-v])([ \\t]*)(:([ \\t]*)\\$?(([a-h]?[a-z])|i[a-v])([ \\t]*))*(:([ \\t]*)\\$?(([a-h]?[a-z])|i[a-v])))"
let colRegex = try! NSRegularExpression.init(pattern: regexStr, options: .caseInsensitive)
let matches = colRegex.matches(in: input, options: [], range: NSRange(location: 0, length: input.utf16.count))
for match in matches {
print("Match >>>>", match)
}
This code prints only a single match A:I and does not match A:IV.
When I change the regex like this :
(\\$?(i[a-v]|([a-h]?[a-z]))([ \\t]*)(:([ \\t]*)\\$?(i[a-v]|([a-h]?[a-z]))([ \\t]*))*(:([ \\t]*)\\$?(i[a-v]|([a-h]?[a-z]))))
The code prints a single match A:IV and not A:I. Even though matching the entire input string is my goal, I do not understand why there is no more than one match for any given input string. There seems to no option that negates this behaviour either.
Our app Api returns a field with custom format for user mentions just like:
"this is a text with mention for #(steve|user_id)".
So before display it on UITextView, need to process the text, find the pattern and replace with something more user friendly.
Final result would be "this is a text with mention for #steve" where #steve should have a link attribute with user_id. Basically the same functionality as Facebook.
First I've created an UITextView extension, with a match function for the regex pattern.
extension UITextView {
func processText(pattern: String) {
let inString = self.text
let regex = try? NSRegularExpression(pattern: pattern, options: [])
let range = NSMakeRange(0, inString.characters.count)
let matches = (regex?.matchesInString(inString, options: [], range: range))! as [NSTextCheckingResult]
let attrString = NSMutableAttributedString(string: inString, attributes:attrs)
//Iterate over regex matches
for match in matches {
//Properly print match range
print(match.range)
//A basic idea to add a link attribute on regex match range
attrString.addAttribute(NSLinkAttributeName, value: "\(schemeMap["#"]):\(must_be_user_id)", range: match.range)
//Still text it's in format #(steve|user_id) how could replace it by #steve keeping the link attribute ?
}
}
}
//To use it
let regex = ""\\#\\(([\\w\\s?]*)\\|([a-zA-Z0-9]{24})\\)""
myTextView.processText(regex)
This is what I have right now, but I'm stucked trying to get final result
Thanks a lot !
I changed your regex a bit, but got a pretty good result. Modified the code a little as well, so you can test it directly in Playgrounds.
func processText() -> NSAttributedString {
let pattern = "(#\\(([^|]*)([^#]*)\\))"
let inString = "this is a text with mention for #(steve|user_id1) and #(alan|user_id2)."
let regex = try? NSRegularExpression(pattern: pattern, options: [])
let range = NSMakeRange(0, inString.characters.count)
let matches = (regex?.matchesInString(inString, options: [], range: range))!
let attrString = NSMutableAttributedString(string: inString, attributes:nil)
print(matches.count)
//Iterate over regex matches
for match in matches.reverse() {
//Properly print match range
print(match.range)
//Get username and userid
let userName = attrString.attributedSubstringFromRange(match.rangeAtIndex(2)).string
let userId = attrString.attributedSubstringFromRange(match.rangeAtIndex(3)).string
//A basic idea to add a link attribute on regex match range
attrString.addAttribute(NSLinkAttributeName, value: "\(userId)", range: match.rangeAtIndex(1))
//Still text it's in format #(steve|user_id) how could replace it by #steve keeping the link attribute ?
attrString.replaceCharactersInRange(match.rangeAtIndex(1), withString: "#\(userName)")
}
return attrString
}
I have a string: "Hey #username that's funny". For a given string, how can I search the string to return all ranges of string with first character # and last character to get the username?
I suppose I can get all indexes of # and for each, get the substringToIndex of the next space character, but wondering if there's an easier way.
If your username can contain only letters and numbers, you can use regular expression for that:
let s = "Hey #username123 that's funny"
if let r = s.rangeOfString("#\\w+", options: NSStringCompareOptions.RegularExpressionSearch) {
let name = s.substringWithRange(r) // #username123"
}
#Vladimir's answer is correct, but if you're trying to find multiple occurrences of "username", this should also work:
let s = "Hey #username123 that's funny"
let ranges: [NSRange]
do {
// Create the regular expression.
let regex = try NSRegularExpression(pattern: "#\\w+", options: [])
// Use the regular expression to get an array of NSTextCheckingResult.
// Use map to extract the range from each result.
ranges = regex.matchesInString(s, options: [], range: NSMakeRange(0, s.characters.count)).map {$0.range}
}
catch {
// There was a problem creating the regular expression
ranges = []
}
for range in ranges {
print((s as NSString).substringWithRange(range))
}