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I just started learning Swift. I have got my code to read from the text file, and the App displays the content of the entire text file. How can I display line by line and call upon that line multiple times?
TextFile.txt contains the following:
1. Banana
2. Apple
3. pear
4. strawberry
5. blueberry
6. blackcurrant
The following is what currently have..
if let path = NSBundle.mainBundle().pathForResource("TextFile", ofType: "txt"){
var data = String(contentsOfFile:path, encoding: NSUTF8StringEncoding, error: nil)
if let content = (data){
TextView.text = content
}
If there is another way of doing this please let me know. It would be much appreciated.
Swift 3.0
if let path = Bundle.main.path(forResource: "TextFile", ofType: "txt") {
do {
let data = try String(contentsOfFile: path, encoding: .utf8)
let myStrings = data.components(separatedBy: .newlines)
TextView.text = myStrings.joined(separator: ", ")
} catch {
print(error)
}
}
The variable myStrings should be each line of the data.
The code used is from:
Reading file line by line in iOS SDK written in Obj-C and using NSString
Check edit history for previous versions of Swift.
Swift 5.5
The solution below shows how to read one line at a time. This is quite different from reading the entire contents into memory. Reading line-by-line scales well if you have a large file to read. Putting an entire file into memory does not scale well for large files.
The example below uses a while loop that quits when there are no more lines, but you can choose a different number of lines to read if you wish.
The code works as follows:
create a URL that tells where the file is located
make sure the file exists
open the file for reading
set up some initial variables for reading
read each line using getLine()
close the file and free the buffer when done
You could make the code less verbose if you wish; I have included comments to explain what the variables' purposes are.
Swift 5.5
import Cocoa
// get URL to the the documents directory in the sandbox
let home = FileManager.default.homeDirectoryForCurrentUser
// add a filename
let fileUrl = home
.appendingPathComponent("Documents")
.appendingPathComponent("my_file")
.appendingPathExtension("txt")
// make sure the file exists
guard FileManager.default.fileExists(atPath: fileUrl.path) else {
preconditionFailure("file expected at \(fileUrl.absoluteString) is missing")
}
// open the file for reading
// note: user should be prompted the first time to allow reading from this location
guard let filePointer:UnsafeMutablePointer<FILE> = fopen(fileUrl.path,"r") else {
preconditionFailure("Could not open file at \(fileUrl.absoluteString)")
}
// a pointer to a null-terminated, UTF-8 encoded sequence of bytes
var lineByteArrayPointer: UnsafeMutablePointer<CChar>? = nil
// see the official Swift documentation for more information on the `defer` statement
// https://docs.swift.org/swift-book/ReferenceManual/Statements.html#grammar_defer-statement
defer {
// remember to close the file when done
fclose(filePointer)
// The buffer should be freed by even if getline() failed.
lineByteArrayPointer?.deallocate()
}
// the smallest multiple of 16 that will fit the byte array for this line
var lineCap: Int = 0
// initial iteration
var bytesRead = getline(&lineByteArrayPointer, &lineCap, filePointer)
while (bytesRead > 0) {
// note: this translates the sequence of bytes to a string using UTF-8 interpretation
let lineAsString = String.init(cString:lineByteArrayPointer!)
// do whatever you need to do with this single line of text
// for debugging, can print it
print(lineAsString)
// updates number of bytes read, for the next iteration
bytesRead = getline(&lineByteArrayPointer, &lineCap, filePointer)
}
If you have a huge file and don't want to load all data to memory with String, Data etc. you can use function readLine() which reads content from standard input line by line until EOF is reached.
let path = "path/file.txt"
guard let file = freopen(path, "r", stdin) else {
return
}
defer {
fclose(file)
}
while let line = readLine() {
print(line)
}
This is not pretty, but I believe it works (on Swift 5). This uses the underlying POSIX getline command for iteration and file reading.
typealias LineState = (
// pointer to a C string representing a line
linePtr:UnsafeMutablePointer<CChar>?,
linecap:Int,
filePtr:UnsafeMutablePointer<FILE>?
)
/// Returns a sequence which iterates through all lines of the the file at the URL.
///
/// - Parameter url: file URL of a file to read
/// - Returns: a Sequence which lazily iterates through lines of the file
///
/// - warning: the caller of this function **must** iterate through all lines of the file, since aborting iteration midway will leak memory and a file pointer
/// - precondition: the file must be UTF8-encoded (which includes, ASCII-encoded)
func lines(ofFile url:URL) -> UnfoldSequence<String,LineState>
{
let initialState:LineState = (linePtr:nil, linecap:0, filePtr:fopen(fileURL.path,"r"))
return sequence(state: initialState, next: { (state) -> String? in
if getline(&state.linePtr, &state.linecap, state.filePtr) > 0,
let theLine = state.linePtr {
return String.init(cString:theLine)
}
else {
if let actualLine = state.linePtr { free(actualLine) }
fclose(state.filePtr)
return nil
}
})
}
Here is how you might use it:
for line in lines(ofFile:myFileURL) {
print(line)
}
Probably the simplest, and easiest way to do this in Swift 5.0, would be the following:
import Foundation
// Determine the file name
let filename = "main.swift"
// Read the contents of the specified file
let contents = try! String(contentsOfFile: filename)
// Split the file into separate lines
let lines = contents.split(separator:"\n")
// Iterate over each line and print the line
for line in lines {
print("\(line)")
}
Note: This reads the entire file into memory, and then just iterates over the file in memory to produce lines....
Credit goes to: https://wiki.codermerlin.com/mediawiki/index.php/Code_Snippet:_Print_a_File_Line-by-Line
Update for Swift 2.0 / Xcode 7.2
do {
if let path = NSBundle.mainBundle().pathForResource("TextFile", ofType: "txt"){
let data = try String(contentsOfFile:path, encoding: NSUTF8StringEncoding)
let myStrings = data.componentsSeparatedByCharactersInSet(NSCharacterSet.newlineCharacterSet())
print(myStrings)
}
} catch let err as NSError {
//do sth with Error
print(err)
}
Also worth to mention is that this code reads a file which is in the project folder (since pathForResource is used), and not in e.g. the documents folder of the device
You probably do want to read the entire file in at once. I bet it's very small.
But then you want to split the resulting string into an array, and then distribute the array's contents among various UI elements, such as table cells.
A simple example:
var x: String = "abc\ndef"
var y = x.componentsSeparatedByString("\n")
// y is now a [String]: ["abc", "def"]
One more getline solution:
Easy to use. Just copy past.
Tested on real project.
extension URL
{
func foreachRow(_ mode:String, _ rowParcer:((String, Int)->Bool) )
{
//Here we should use path not the absoluteString (wich contains file://)
let path = self.path
guard let cfilePath = (path as NSString).utf8String,
let m = (mode as NSString).utf8String
else {return}
//Open file with specific mode (just use "r")
guard let file = fopen(cfilePath, m)
else {
print("fopen can't open file: \"\(path)\", mode: \"\(mode)\"")
return
}
//Row capacity for getline()
var cap = 0
var row_index = 0
//Row container for getline()
var cline:UnsafeMutablePointer<CChar>? = nil
//Free memory and close file at the end
defer{free(cline); fclose(file)}
while getline(&cline, &cap, file) > 0
{
if let crow = cline,
// the output line may contain '\n' that's why we filtered it
let s = String(utf8String: crow)?.filter({($0.asciiValue ?? 0) >= 32})
{
if rowParcer(s, row_index)
{
break
}
}
row_index += 1
}
}
}
Usage:
let token = "mtllib "
var mtlRow = ""
largeObjFileURL.foreachRow("r"){ (row, i) -> Bool in
if row.hasPrefix(token)
{
mtlRow = row
return true // end of file reading
}
return false // continue file reading
}
Here is an example of writeing and reading a text file one line at a time
in Swift version 5. Reads one line in at a time and includes EOF detection
//
// main.swift
// IO
//
// Created by Michael LeVine on 8/30/22.
//
import Foundation
let file = "file.txt" //this is the file. we will write to and read from it
let text = "some text\n" //just a text
// test file will be placed on deasktop
let dir = FileManager.default.urls(for: .desktopDirectory, in: .userDomainMask).first
let fileURL = dir!.appendingPathComponent(file).path
let fileURL2 = dir!.appendingPathComponent(file)
let fileManager = FileManager.default
// the following variable used by eof detection which also use var fileManager internally
var eofOffset: UInt64 = 0
if fileManager.fileExists(atPath: fileURL) {
do { try fileManager.removeItem(atPath: fileURL)}
catch {
print("Error removeing old \(fileURL)")
exit(1)
}
}
// create the new file
fileManager.createFile(atPath: fileURL, contents:Data(" ".utf8), attributes: nil)
var fileHandle = FileHandle(forWritingAtPath: fileURL)
//writing
for _ in 1...10 {
fileHandle!.write(text.data(using: .utf8)!)
}
do {
try fileHandle!.close()
}
catch { print("write close error \(error)")
exit(1)
}
// now to read text file by 2 methods
// first use String to read whole file in one gulp
let contents = try! String(contentsOfFile: fileURL)
let lines = contents.split(separator: "\n")
var i: Int = 0
// print out one way
for line in lines {
print("\(i) \(line)")
i=i+1
}
// printout another way
for j in 0...9 {
print("\(i) \(j) \(lines[j])")
i = i + 1
}
//Open up to see about reading line at a time
fileHandle = FileHandle(forReadingAtPath: fileURL)
eofInit() // must be called immediately after fileHandle init
var outputLine: String = ""
i = 0
// read a line and print it out as recieved
while true {
outputLine = getLine()
if eofTest(){
if outputLine.count > 0 {
print("\(i) \(outputLine)")
}
exit(1)
}
print("\(i) \(outputLine)")
i = i + 1
}
// function reads one character at each call and returns it as a 1 character string
// is called only by "getLine"
func getChar() -> String {
var ch: Data
if eofTest() {
return ""
}
do {
try ch = fileHandle!.read(upToCount: 1)! // read 1 character from text file
} catch { print("read 1 char \(error)")
exit(1)
}
let ch2: UnicodeScalar = UnicodeScalar(ch[0]) // convert to unicode scaler as intermediate value
let ch3: String = String(ch2) // Now create string containing that one returned character
return ch3 // and pass to calling function
}
// read in whole line one character at a time -- assumes line terminated by linefeed
func getLine() -> String {
var outputLine : String = ""
var char : String = ""
// keep fetching characters till line feed/eof found
lineLoop:
while true { // its an infinite loop
if eofTest() {
break lineLoop
}
char = getChar() // get next character
if char == "\n" { // test for linefeed
break lineLoop // if found exit loop
}
outputLine.append(char) // lf not found -- append char to output line
}
return outputLine // got line -- return it to calling routine
}
//eof handleing
//init routine must be called immediately after fileHandle inited to get current position
// at start of file
func eofInit()
{ var beginningOffset: UInt64 = 0
do {
try beginningOffset = fileHandle!.offset()
try eofOffset = fileHandle!.seekToEnd()
try fileHandle!.seek(toOffset: beginningOffset)
} catch {
print("Init eof detection error \(error)")
}
}
func eofTest() -> Bool{
var current: UInt64 = 0
do {
current = try fileHandle!.offset()
} catch {
print("eof test get current \(error)")
exit(1)
}
if current < eofOffset {
return false
} else {
return true
}
}
Based on Jason Cross answer simplified version line by line reader(gist).
import Darwin
class FileLineReader {
init?(path: String, removeNewLineOnEnd: Bool = true) {
file = fopen(path, "r")
self.removeNewLineOnEnd = removeNewLineOnEnd
if file == nil {
return nil
}
}
deinit {
fclose(file)
}
var iterator: AnyIterator<String> {
return AnyIterator(self.getNextLine)
}
func getNextLine() -> String? {
var line: UnsafeMutablePointer<CChar>!
var linecap: Int = 0
defer { free(line) }
if getline(&line, &linecap, file) > 0 {
if removeNewLineOnEnd {
var i = 0
while line[i] != 0 { i += 1 }
if i > 0 && line[i-1] == 10 { // new line symbol
line[i-1] = 0
}
}
return String(cString: line)
} else {
return nil
}
}
private let file: UnsafeMutablePointer<FILE>!
private let removeNewLineOnEnd: Bool
}
iUrii approach may not work if you need to open several files.
In an iPhone app I am developing, there is a setting in which you can enter a URL, because of form & function this URL needs to be validated online as well as offline.
So far I haven't been able to find any method to validate the url, so the question is;
How do I validate an URL input on the iPhone (Objective-C) online as well as offline?
Why not instead simply rely on Foundation.framework?
That does the job and does not require RegexKit :
NSURL *candidateURL = [NSURL URLWithString:candidate];
// WARNING > "test" is an URL according to RFCs, being just a path
// so you still should check scheme and all other NSURL attributes you need
if (candidateURL && candidateURL.scheme && candidateURL.host) {
// candidate is a well-formed url with:
// - a scheme (like http://)
// - a host (like stackoverflow.com)
}
According to Apple documentation :
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 conform to RFC 2396. This method parses URLString according to RFCs 1738 and 1808.
Return Value
An NSURL object initialized with URLString. If the string was malformed, returns nil.
Thanks to this post, you can avoid using RegexKit.
Here is my solution (works for iphone development with iOS > 3.0) :
- (BOOL) validateUrl: (NSString *) candidate {
NSString *urlRegEx =
#"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
NSPredicate *urlTest = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", urlRegEx];
return [urlTest evaluateWithObject:candidate];
}
If you want to check in Swift my solution given below:
func isValidUrl(url: String) -> Bool {
let urlRegEx = "^(https?://)?(www\\.)?([-a-z0-9]{1,63}\\.)*?[a-z0-9][-a-z0-9]{0,61}[a-z0-9]\\.[a-z]{2,6}(/[-\\w#\\+\\.~#\\?&/=%]*)?$"
let urlTest = NSPredicate(format:"SELF MATCHES %#", urlRegEx)
let result = urlTest.evaluate(with: url)
return result
}
Instead of writing your own regular expressions, rely on Apple's. I have been using a category on NSString that uses NSDataDetector to test for the presence of a link within a string. If the range of the link found by NSDataDetector equals the length of the entire string, then it is a valid URL.
- (BOOL)isValidURL {
NSUInteger length = [self length];
// Empty strings should return NO
if (length > 0) {
NSError *error = nil;
NSDataDetector *dataDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:&error];
if (dataDetector && !error) {
NSRange range = NSMakeRange(0, length);
NSRange notFoundRange = (NSRange){NSNotFound, 0};
NSRange linkRange = [dataDetector rangeOfFirstMatchInString:self options:0 range:range];
if (!NSEqualRanges(notFoundRange, linkRange) && NSEqualRanges(range, linkRange)) {
return YES;
}
}
else {
NSLog(#"Could not create link data detector: %# %#", [error localizedDescription], [error userInfo]);
}
}
return NO;
}
My solution with Swift:
func validateUrl (stringURL : NSString) -> Bool {
var urlRegEx = "((https|http)://)((\\w|-)+)(([.]|[/])((\\w|-)+))+"
let predicate = NSPredicate(format:"SELF MATCHES %#", argumentArray:[urlRegEx])
var urlTest = NSPredicate.predicateWithSubstitutionVariables(predicate)
return predicate.evaluateWithObject(stringURL)
}
For Test:
var boolean1 = validateUrl("http.s://www.gmail.com")
var boolean2 = validateUrl("https:.//gmailcom")
var boolean3 = validateUrl("https://gmail.me.")
var boolean4 = validateUrl("https://www.gmail.me.com.com.com.com")
var boolean6 = validateUrl("http:/./ww-w.wowone.com")
var boolean7 = validateUrl("http://.www.wowone")
var boolean8 = validateUrl("http://www.wow-one.com")
var boolean9 = validateUrl("http://www.wow_one.com")
var boolean10 = validateUrl("http://.")
var boolean11 = validateUrl("http://")
var boolean12 = validateUrl("http://k")
Results:
false
false
false
true
false
false
true
true
false
false
false
use this-
NSString *urlRegEx = #"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w- ./?%&=]*)?";
I solved the problem using RegexKit, and build a quick regex to validate a URL;
NSString *regexString = #"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
NSString *subjectString = brandLink.text;
NSString *matchedString = [subjectString stringByMatching:regexString];
Then I check if the matchedString is equal to the subjectString and if that is the case the url is valid :)
Correct me if my regex is wrong ;)
I've found the easiest way to do this is like so:
- (BOOL)validateUrl: (NSURL *)candidate
{
NSURLRequest *req = [NSURLRequest requestWithURL:candidate];
return [NSURLConnection canHandleRequest:req];
}
Oddly enough, I didn't really find a solution here that was very simple, yet still did an okay job for handling http / https links.
Keep in mind, THIS IS NOT a perfect solution, but it worked for the cases below. In summary, the regex tests whether the URL starts with http:// or https://, then checks for at least 1 character, then checks for a dot, and then again checks for at least 1 character. No spaces allowed.
+ (BOOL)validateLink:(NSString *)link
{
NSString *regex = #"(?i)(http|https)(:\\/\\/)([^ .]+)(\\.)([^ \n]+)";
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", regex];
return [predicate evaluateWithObject:link];
}
Tested VALID against these URLs:
#"HTTP://FOO.COM",
#"HTTPS://FOO.COM",
#"http://foo.com/blah_blah",
#"http://foo.com/blah_blah/",
#"http://foo.com/blah_blah_(wikipedia)",
#"http://foo.com/blah_blah_(wikipedia)_(again)",
#"http://www.example.com/wpstyle/?p=364",
#"https://www.example.com/foo/?bar=baz&inga=42&quux",
#"http://✪df.ws/123",
#"http://userid:password#example.com:8080",
#"http://userid:password#example.com:8080/",
#"http://userid#example.com",
#"http://userid#example.com/",
#"http://userid#example.com:8080",
#"http://userid#example.com:8080/",
#"http://userid:password#example.com",
#"http://userid:password#example.com/",
#"http://142.42.1.1/",
#"http://142.42.1.1:8080/",
#"http://➡.ws/䨹",
#"http://⌘.ws",
#"http://⌘.ws/",
#"http://foo.com/blah_(wikipedia)#cite-",
#"http://foo.com/blah_(wikipedia)_blah#cite-",
#"http://foo.com/unicode_(✪)_in_parens",
#"http://foo.com/(something)?after=parens",
#"http://☺.damowmow.com/",
#"http://code.google.com/events/#&product=browser",
#"http://j.mp",
#"http://foo.bar/?q=Test%20URL-encoded%20stuff",
#"http://مثال.إختبار",
#"http://例子.测试",
#"http://उदाहरण.परीक्षा",
#"http://-.~_!$&'()*+,;=:%40:80%2f::::::#example.com",
#"http://1337.net",
#"http://a.b-c.de",
#"http://223.255.255.254"
Tested INVALID against these URLs:
#"",
#"foo",
#"ftp://foo.com",
#"ftp://foo.com",
#"http://..",
#"http://..",
#"http://../",
#"//",
#"///",
#"http://##/",
#"http://.www.foo.bar./",
#"rdar://1234",
#"http://foo.bar?q=Spaces should be encoded",
#"http:// shouldfail.com",
#":// should fail"
Source of URLs:
https://mathiasbynens.be/demo/url-regex
You can use this if you do not want http or https or www
NSString *urlRegEx = #"^(http(s)?://)?((www)?\.)?[\w]+\.[\w]+";
example
- (void) testUrl:(NSString *)urlString{
NSLog(#"%#: %#", ([self isValidUrl:urlString] ? #"VALID" : #"INVALID"), urlString);
}
- (void)doTestUrls{
[self testUrl:#"google"];
[self testUrl:#"google.de"];
[self testUrl:#"www.google.de"];
[self testUrl:#"http://www.google.de"];
[self testUrl:#"http://google.de"];
}
Output:
INVALID: google
VALID: google.de
VALID: www.google.de
VALID: http://www.google.de
VALID: http://google.de
Lefakir's solution has one issue.
His regex can't match with "http://instagram.com/p/4Mz3dTJ-ra/".
Url component has combined numerical and literal character. His regex fail such urls.
Here is my improvement.
"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*)+)+(/)?(\\?.*)?"
Below code will let you find the valid URLs
NSPredicate *websitePredicate = [NSPredicate predicateWithFormat:#"SELF MATCHES %#",#"^(((((h|H)(t|T){2}(p|P)s?)|((f|F)(t|T)(p|P)))://(w{3}.)?)|(w{3}.))[A-Za-z0-9]+(.[A-Za-z0-9-:;\?#_]+)+"];
if ([websitePredicate evaluateWithObject:##MY_STRING##])
{
printf"Valid"
}
for such URLS
http://123.com
https://123.com
http://www.123.com
https://www.123.com
ftp://123.com
ftp://www.123.com
www.something.com
The approved answer is incorrect.
I have an URL with an "-" in it, and the validation fails.
Tweeked Vaibhav's answer to support G+ links:
NSString *urlRegEx = #"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w-\\+ ./?%&=]*)?";
Some URL's without / at the end are not detected as the correct one in the solutions above. So this might be helpful.
extension String {
func isValidURL() -> Bool{
let length:Int = self.characters.count
var err:NSError?
var dataDetector:NSDataDetector? = NSDataDetector()
do{
dataDetector = try NSDataDetector(types: NSTextCheckingType.Link.rawValue)
}catch{
err = error as NSError
}
if dataDetector != nil{
let range = NSMakeRange(0, length)
let notFoundRange = NSRange(location: NSNotFound, length: 0)
let linkRange = dataDetector?.rangeOfFirstMatchInString(self, options: NSMatchingOptions.init(rawValue: 0), range: range)
if !NSEqualRanges(notFoundRange, linkRange!) && NSEqualRanges(range, linkRange!){
return true
}
}else{
print("Could not create link data detector: \(err?.localizedDescription): \(err?.userInfo)")
}
return false
}
}
URL Validation in Swift
Details
Xcode 8.2.1, Swift 3
Code
enum URLSchemes: String
import Foundation
enum URLSchemes: String {
case http = "http://", https = "https://", ftp = "ftp://", unknown = "unknown://"
static func detectScheme(urlString: String) -> URLSchemes {
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .http) {
return .http
}
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .https) {
return .https
}
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .ftp) {
return .ftp
}
return .unknown
}
static func getAllSchemes(separetedBy separator: String) -> String {
return "\(URLSchemes.http.rawValue)\(separator)\(URLSchemes.https.rawValue)\(separator)\(URLSchemes.ftp.rawValue)"
}
private static func isSchemeCorrect(urlString: String, scheme: URLSchemes) -> Bool {
if urlString.replacingOccurrences(of: scheme.rawValue, with: "") == urlString {
return false
}
return true
}
}
extension String
import Foundation
extension String {
var isUrl: Bool {
// for http://regexr.com checking
// (?:(?:https?|ftp):\/\/)(?:xn--)?(?:\S+(?::\S*)?#)?(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[#-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:\/[^\s]*)?
let schemes = URLSchemes.getAllSchemes(separetedBy: "|").replacingOccurrences(of: "://", with: "")
let regex = "(?:(?:\(schemes)):\\/\\/)(?:xn--)?(?:\\S+(?::\\S*)?#)?(?:(?!10(?:\\.\\d{1,3}){3})(?!127(?:\\.\\d{1,3}){3})(?!169\\.254(?:\\.\\d{1,3}){2})(?!192\\.168(?:\\.\\d{1,3}){2})(?!172\\.(?:1[6-9]|2\\d|3[0-1])(?:\\.\\d{1,3}){2})(?:[1-9]\\d?|1\\d\\d|2[01]\\d|22[0-3])(?:\\.(?:1?\\d{1,2}|2[0-4]\\d|25[0-5])){2}(?:\\.(?:[1-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))|(?:(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)(?:\\.(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)*(?:\\.(?:[#-z\\u00a1-\\uffff]{2,})))(?::\\d{2,5})?(?:\\/[^\\s]*)?"
let regularExpression = try! NSRegularExpression(pattern: regex, options: [])
let range = NSRange(location: 0, length: self.characters.count)
let matches = regularExpression.matches(in: self, options: [], range: range)
for match in matches {
if range.location == match.range.location && range.length == match.range.length {
return true
}
}
return false
}
var toURL: URL? {
let urlChecker: (String)->(URL?) = { url_string in
if url_string.isUrl, let url = URL(string: url_string) {
return url
}
return nil
}
if !contains(".") {
return nil
}
if let url = urlChecker(self) {
return url
}
let scheme = URLSchemes.detectScheme(urlString: self)
if scheme == .unknown {
let newEncodedString = URLSchemes.http.rawValue + self
if let url = urlChecker(newEncodedString) {
return url
}
}
return nil
}
}
Usage
func tests() {
chekUrl(urlString:"http://example.com")
chekUrl(urlString:"https://example.com")
chekUrl(urlString:"http://example.com/dir/file.php?var=moo")
chekUrl(urlString:"http://xn--h1aehhjhg.xn--d1acj3b")
chekUrl(urlString:"http://www.example.com/wpstyle/?p=364")
chekUrl(urlString:"http://-.~_!$&'()*+,;=:%40:80%2f::::::#example.com")
chekUrl(urlString:"http://example.com")
chekUrl(urlString:"http://xn--d1acpjx3f.xn--p1ai")
chekUrl(urlString:"http://xn--74h.damowmow.com/")
chekUrl(urlString:"ftp://example.com:129/myfiles")
chekUrl(urlString:"ftp://user:pass#site.com:21/file/dir")
chekUrl(urlString:"ftp://ftp.example.com:2828/asdah%20asdah.gif")
chekUrl(urlString:"http://142.42.1.1:8080/")
chekUrl(urlString:"http://142.42.1.1/")
chekUrl(urlString:"http://userid:password#example.com:8080")
chekUrl(urlString:"http://userid#example.com")
chekUrl(urlString:"http://userid#example.com:8080")
chekUrl(urlString:"http://foo.com/blah_(wikipedia)#cite-1")
chekUrl(urlString:"http://foo.com/(something)?after=parens")
print("\n----------------------------------------------\n")
chekUrl(urlString:".")
chekUrl(urlString:" ")
chekUrl(urlString:"")
chekUrl(urlString:"-/:;()₽&#.,?!'{}[];'<>+_)(*#^%$")
chekUrl(urlString:"localhost")
chekUrl(urlString:"yandex.")
chekUrl(urlString:"коряга")
chekUrl(urlString:"http:///a")
chekUrl(urlString:"ftps://foo.bar/")
chekUrl(urlString:"rdar://1234")
chekUrl(urlString:"h://test")
chekUrl(urlString:":// should fail")
chekUrl(urlString:"http://-error-.invalid/")
chekUrl(urlString:"http://.www.example.com/")
}
func chekUrl(urlString: String) {
var result = ""
if urlString.isUrl {
result += "url: "
} else {
result += "not url: "
}
result += "\"\(urlString)\""
print(result)
}
Result
Objective C
- (BOOL)validateUrlString:(NSString*)urlString
{
if (!urlString)
{
return NO;
}
NSDataDetector *linkDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:nil];
NSRange urlStringRange = NSMakeRange(0, [urlString length]);
NSMatchingOptions matchingOptions = 0;
if (1 != [linkDetector numberOfMatchesInString:urlString options:matchingOptions range:urlStringRange])
{
return NO;
}
NSTextCheckingResult *checkingResult = [linkDetector firstMatchInString:urlString options:matchingOptions range:urlStringRange];
return checkingResult.resultType == NSTextCheckingTypeLink && NSEqualRanges(checkingResult.range, urlStringRange);
}
Hope this helps!
did you mean to check if what the user entered is a URL? It can be as simple as a regular expression, for example checking if the string contain www. (this is the way that yahoo messenger checks if the user status is a link or not)
Hope that help
Selfishly, I would suggest using a KSURLFormatter instance to both validate input, and convert it to something NSURL can handle.
I have created inherited class of UITextField which can handle all kind of validation using regex string. In this you just need to give them all the regex string in sequence and their message that you want to show when validation get failed. You can check my blog for more info, it will really help you
http://dhawaldawar.wordpress.com/2014/06/11/uitextfield-validation-ios/
Extending #Anthony's answer to swift, I wrote a category on String which returns an optional NSURL. The return value is nil if the String can not be validated to be a URL.
import Foundation
// A private global detector variable which can be reused.
private let detector = try! NSDataDetector(types: NSTextCheckingType.Link.rawValue)
extension String {
func URL() -> NSURL? {
let textRange = NSMakeRange(0, self.characters.count)
guard let URLResult = detector.firstMatchInString(self, options: [], range: textRange) else {
return nil
}
// This checks that the whole string is the detected URL. In case
// you don't have such a requirement, you can remove this code
// and return the URL from URLResult.
guard NSEqualRanges(URLResult.range, textRange) else {
return nil
}
return NSURL(string: self)
}
}
func checkValidUrl(_ strUrl: String) -> Bool {
let urlRegEx: String = "(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+"
let urlTest = NSPredicate(format: "SELF MATCHES %#", urlRegEx)
return urlTest.evaluate(with: strUrl)
}
My solution in Swift 5:
extension String {
func isValidUrl() -> Bool {
do {
let detector = try NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
// check if the string has link inside
return detector.numberOfMatches(in: self, options: [], range: .init( location: 0, length: utf16.count)) > 0
} catch {
print("Error during NSDatadetector initialization \(error)" )
}
return false
}
}
how to rewrite this objective-c language to swift?
NSString *filePath = #"/Applications/MySample.app";
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath])
{
// avoid open add friend
}
regards.
Equivalent Swift 3 Code:
let filePath = "/Applications/MySample.app"
if (FileManager.default.fileExists(atPath: filePath)) {
// avoid open add friend
}
Swift 2
let filePath = "/Applications/MySample.app"
if (NSFileManager.defaultManager().fileExistsAtPath(filePath))
{
// avoid open add friend
}
Some years after the question has been asked I recommend to take rewrite literally and use the URL related API
let fileURL = URL(fileURLWithPath:"/Applications/MySample.app")
if let _ = try? fileURL.checkResourceIsReachable() {
// file exists
}
let path = "/Applications/MySample.app"
let hasFile = FileManager().fileExists(atPath: path)
if hasFile {
// use file
}
else {
// possibly inform user the file does not exist
}
In my today extension with my device unlocked, this line of code works as expected, returning the data from the image path:
let imageData = NSData(contentsOfFile: path)
However when my device is locked with a passcode, it returns nil. Is there any way to access images in the file system when the device is locked? I can access UserDefaults just fine, but not files in the directory for my shared group. Here is how I am creating the path, calling imagePath, which is correctly populated with the path I expect in both cases:
func rootFilePath() -> String? {
let manager = NSFileManager()
let containerURL = manager.containerURLForSecurityApplicationGroupIdentifier(GROUP_ID)
if let unwrappedURL = containerURL {
return unwrappedURL.path
}
else {
return nil
}
}
func imagePath() -> String? {
let rootPath = rootFilePath()
if let uPath = rootPath {
return "\(uPath)/\(imageId).png"
}
else {
return nil
}
}
I just figured it out! You need to set the file permissions accordingly:
NSFileManager *fm = [[NSFileManager alloc] init];
NSDictionary *attribs = #{NSFileProtectionKey : NSFileProtectionNone};
NSError *unprotectError = nil;
BOOL unprotectSuccess = [fm setAttributes:attribs
ofItemAtPath:[containerURL path]
error:&unprotectError];
if (!unprotectSuccess) {
NSLog(#"Unable to remove protection from file! %#", unprotectError);
}
In many cases you wouldn't normally want to do this, but because the information is intended to be viewed from the lock screen, I'm OK with removing file protection.
In an iPhone app I am developing, there is a setting in which you can enter a URL, because of form & function this URL needs to be validated online as well as offline.
So far I haven't been able to find any method to validate the url, so the question is;
How do I validate an URL input on the iPhone (Objective-C) online as well as offline?
Why not instead simply rely on Foundation.framework?
That does the job and does not require RegexKit :
NSURL *candidateURL = [NSURL URLWithString:candidate];
// WARNING > "test" is an URL according to RFCs, being just a path
// so you still should check scheme and all other NSURL attributes you need
if (candidateURL && candidateURL.scheme && candidateURL.host) {
// candidate is a well-formed url with:
// - a scheme (like http://)
// - a host (like stackoverflow.com)
}
According to Apple documentation :
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 conform to RFC 2396. This method parses URLString according to RFCs 1738 and 1808.
Return Value
An NSURL object initialized with URLString. If the string was malformed, returns nil.
Thanks to this post, you can avoid using RegexKit.
Here is my solution (works for iphone development with iOS > 3.0) :
- (BOOL) validateUrl: (NSString *) candidate {
NSString *urlRegEx =
#"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
NSPredicate *urlTest = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", urlRegEx];
return [urlTest evaluateWithObject:candidate];
}
If you want to check in Swift my solution given below:
func isValidUrl(url: String) -> Bool {
let urlRegEx = "^(https?://)?(www\\.)?([-a-z0-9]{1,63}\\.)*?[a-z0-9][-a-z0-9]{0,61}[a-z0-9]\\.[a-z]{2,6}(/[-\\w#\\+\\.~#\\?&/=%]*)?$"
let urlTest = NSPredicate(format:"SELF MATCHES %#", urlRegEx)
let result = urlTest.evaluate(with: url)
return result
}
Instead of writing your own regular expressions, rely on Apple's. I have been using a category on NSString that uses NSDataDetector to test for the presence of a link within a string. If the range of the link found by NSDataDetector equals the length of the entire string, then it is a valid URL.
- (BOOL)isValidURL {
NSUInteger length = [self length];
// Empty strings should return NO
if (length > 0) {
NSError *error = nil;
NSDataDetector *dataDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:&error];
if (dataDetector && !error) {
NSRange range = NSMakeRange(0, length);
NSRange notFoundRange = (NSRange){NSNotFound, 0};
NSRange linkRange = [dataDetector rangeOfFirstMatchInString:self options:0 range:range];
if (!NSEqualRanges(notFoundRange, linkRange) && NSEqualRanges(range, linkRange)) {
return YES;
}
}
else {
NSLog(#"Could not create link data detector: %# %#", [error localizedDescription], [error userInfo]);
}
}
return NO;
}
My solution with Swift:
func validateUrl (stringURL : NSString) -> Bool {
var urlRegEx = "((https|http)://)((\\w|-)+)(([.]|[/])((\\w|-)+))+"
let predicate = NSPredicate(format:"SELF MATCHES %#", argumentArray:[urlRegEx])
var urlTest = NSPredicate.predicateWithSubstitutionVariables(predicate)
return predicate.evaluateWithObject(stringURL)
}
For Test:
var boolean1 = validateUrl("http.s://www.gmail.com")
var boolean2 = validateUrl("https:.//gmailcom")
var boolean3 = validateUrl("https://gmail.me.")
var boolean4 = validateUrl("https://www.gmail.me.com.com.com.com")
var boolean6 = validateUrl("http:/./ww-w.wowone.com")
var boolean7 = validateUrl("http://.www.wowone")
var boolean8 = validateUrl("http://www.wow-one.com")
var boolean9 = validateUrl("http://www.wow_one.com")
var boolean10 = validateUrl("http://.")
var boolean11 = validateUrl("http://")
var boolean12 = validateUrl("http://k")
Results:
false
false
false
true
false
false
true
true
false
false
false
use this-
NSString *urlRegEx = #"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w- ./?%&=]*)?";
I solved the problem using RegexKit, and build a quick regex to validate a URL;
NSString *regexString = #"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+";
NSString *subjectString = brandLink.text;
NSString *matchedString = [subjectString stringByMatching:regexString];
Then I check if the matchedString is equal to the subjectString and if that is the case the url is valid :)
Correct me if my regex is wrong ;)
I've found the easiest way to do this is like so:
- (BOOL)validateUrl: (NSURL *)candidate
{
NSURLRequest *req = [NSURLRequest requestWithURL:candidate];
return [NSURLConnection canHandleRequest:req];
}
Oddly enough, I didn't really find a solution here that was very simple, yet still did an okay job for handling http / https links.
Keep in mind, THIS IS NOT a perfect solution, but it worked for the cases below. In summary, the regex tests whether the URL starts with http:// or https://, then checks for at least 1 character, then checks for a dot, and then again checks for at least 1 character. No spaces allowed.
+ (BOOL)validateLink:(NSString *)link
{
NSString *regex = #"(?i)(http|https)(:\\/\\/)([^ .]+)(\\.)([^ \n]+)";
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF MATCHES %#", regex];
return [predicate evaluateWithObject:link];
}
Tested VALID against these URLs:
#"HTTP://FOO.COM",
#"HTTPS://FOO.COM",
#"http://foo.com/blah_blah",
#"http://foo.com/blah_blah/",
#"http://foo.com/blah_blah_(wikipedia)",
#"http://foo.com/blah_blah_(wikipedia)_(again)",
#"http://www.example.com/wpstyle/?p=364",
#"https://www.example.com/foo/?bar=baz&inga=42&quux",
#"http://✪df.ws/123",
#"http://userid:password#example.com:8080",
#"http://userid:password#example.com:8080/",
#"http://userid#example.com",
#"http://userid#example.com/",
#"http://userid#example.com:8080",
#"http://userid#example.com:8080/",
#"http://userid:password#example.com",
#"http://userid:password#example.com/",
#"http://142.42.1.1/",
#"http://142.42.1.1:8080/",
#"http://➡.ws/䨹",
#"http://⌘.ws",
#"http://⌘.ws/",
#"http://foo.com/blah_(wikipedia)#cite-",
#"http://foo.com/blah_(wikipedia)_blah#cite-",
#"http://foo.com/unicode_(✪)_in_parens",
#"http://foo.com/(something)?after=parens",
#"http://☺.damowmow.com/",
#"http://code.google.com/events/#&product=browser",
#"http://j.mp",
#"http://foo.bar/?q=Test%20URL-encoded%20stuff",
#"http://مثال.إختبار",
#"http://例子.测试",
#"http://उदाहरण.परीक्षा",
#"http://-.~_!$&'()*+,;=:%40:80%2f::::::#example.com",
#"http://1337.net",
#"http://a.b-c.de",
#"http://223.255.255.254"
Tested INVALID against these URLs:
#"",
#"foo",
#"ftp://foo.com",
#"ftp://foo.com",
#"http://..",
#"http://..",
#"http://../",
#"//",
#"///",
#"http://##/",
#"http://.www.foo.bar./",
#"rdar://1234",
#"http://foo.bar?q=Spaces should be encoded",
#"http:// shouldfail.com",
#":// should fail"
Source of URLs:
https://mathiasbynens.be/demo/url-regex
You can use this if you do not want http or https or www
NSString *urlRegEx = #"^(http(s)?://)?((www)?\.)?[\w]+\.[\w]+";
example
- (void) testUrl:(NSString *)urlString{
NSLog(#"%#: %#", ([self isValidUrl:urlString] ? #"VALID" : #"INVALID"), urlString);
}
- (void)doTestUrls{
[self testUrl:#"google"];
[self testUrl:#"google.de"];
[self testUrl:#"www.google.de"];
[self testUrl:#"http://www.google.de"];
[self testUrl:#"http://google.de"];
}
Output:
INVALID: google
VALID: google.de
VALID: www.google.de
VALID: http://www.google.de
VALID: http://google.de
Lefakir's solution has one issue.
His regex can't match with "http://instagram.com/p/4Mz3dTJ-ra/".
Url component has combined numerical and literal character. His regex fail such urls.
Here is my improvement.
"(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*)+)+(/)?(\\?.*)?"
Below code will let you find the valid URLs
NSPredicate *websitePredicate = [NSPredicate predicateWithFormat:#"SELF MATCHES %#",#"^(((((h|H)(t|T){2}(p|P)s?)|((f|F)(t|T)(p|P)))://(w{3}.)?)|(w{3}.))[A-Za-z0-9]+(.[A-Za-z0-9-:;\?#_]+)+"];
if ([websitePredicate evaluateWithObject:##MY_STRING##])
{
printf"Valid"
}
for such URLS
http://123.com
https://123.com
http://www.123.com
https://www.123.com
ftp://123.com
ftp://www.123.com
www.something.com
The approved answer is incorrect.
I have an URL with an "-" in it, and the validation fails.
Tweeked Vaibhav's answer to support G+ links:
NSString *urlRegEx = #"http(s)?://([\\w-]+\\.)+[\\w-]+(/[\\w-\\+ ./?%&=]*)?";
Some URL's without / at the end are not detected as the correct one in the solutions above. So this might be helpful.
extension String {
func isValidURL() -> Bool{
let length:Int = self.characters.count
var err:NSError?
var dataDetector:NSDataDetector? = NSDataDetector()
do{
dataDetector = try NSDataDetector(types: NSTextCheckingType.Link.rawValue)
}catch{
err = error as NSError
}
if dataDetector != nil{
let range = NSMakeRange(0, length)
let notFoundRange = NSRange(location: NSNotFound, length: 0)
let linkRange = dataDetector?.rangeOfFirstMatchInString(self, options: NSMatchingOptions.init(rawValue: 0), range: range)
if !NSEqualRanges(notFoundRange, linkRange!) && NSEqualRanges(range, linkRange!){
return true
}
}else{
print("Could not create link data detector: \(err?.localizedDescription): \(err?.userInfo)")
}
return false
}
}
URL Validation in Swift
Details
Xcode 8.2.1, Swift 3
Code
enum URLSchemes: String
import Foundation
enum URLSchemes: String {
case http = "http://", https = "https://", ftp = "ftp://", unknown = "unknown://"
static func detectScheme(urlString: String) -> URLSchemes {
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .http) {
return .http
}
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .https) {
return .https
}
if URLSchemes.isSchemeCorrect(urlString: urlString, scheme: .ftp) {
return .ftp
}
return .unknown
}
static func getAllSchemes(separetedBy separator: String) -> String {
return "\(URLSchemes.http.rawValue)\(separator)\(URLSchemes.https.rawValue)\(separator)\(URLSchemes.ftp.rawValue)"
}
private static func isSchemeCorrect(urlString: String, scheme: URLSchemes) -> Bool {
if urlString.replacingOccurrences(of: scheme.rawValue, with: "") == urlString {
return false
}
return true
}
}
extension String
import Foundation
extension String {
var isUrl: Bool {
// for http://regexr.com checking
// (?:(?:https?|ftp):\/\/)(?:xn--)?(?:\S+(?::\S*)?#)?(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]+-?)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[#-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:\/[^\s]*)?
let schemes = URLSchemes.getAllSchemes(separetedBy: "|").replacingOccurrences(of: "://", with: "")
let regex = "(?:(?:\(schemes)):\\/\\/)(?:xn--)?(?:\\S+(?::\\S*)?#)?(?:(?!10(?:\\.\\d{1,3}){3})(?!127(?:\\.\\d{1,3}){3})(?!169\\.254(?:\\.\\d{1,3}){2})(?!192\\.168(?:\\.\\d{1,3}){2})(?!172\\.(?:1[6-9]|2\\d|3[0-1])(?:\\.\\d{1,3}){2})(?:[1-9]\\d?|1\\d\\d|2[01]\\d|22[0-3])(?:\\.(?:1?\\d{1,2}|2[0-4]\\d|25[0-5])){2}(?:\\.(?:[1-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))|(?:(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)(?:\\.(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)*(?:\\.(?:[#-z\\u00a1-\\uffff]{2,})))(?::\\d{2,5})?(?:\\/[^\\s]*)?"
let regularExpression = try! NSRegularExpression(pattern: regex, options: [])
let range = NSRange(location: 0, length: self.characters.count)
let matches = regularExpression.matches(in: self, options: [], range: range)
for match in matches {
if range.location == match.range.location && range.length == match.range.length {
return true
}
}
return false
}
var toURL: URL? {
let urlChecker: (String)->(URL?) = { url_string in
if url_string.isUrl, let url = URL(string: url_string) {
return url
}
return nil
}
if !contains(".") {
return nil
}
if let url = urlChecker(self) {
return url
}
let scheme = URLSchemes.detectScheme(urlString: self)
if scheme == .unknown {
let newEncodedString = URLSchemes.http.rawValue + self
if let url = urlChecker(newEncodedString) {
return url
}
}
return nil
}
}
Usage
func tests() {
chekUrl(urlString:"http://example.com")
chekUrl(urlString:"https://example.com")
chekUrl(urlString:"http://example.com/dir/file.php?var=moo")
chekUrl(urlString:"http://xn--h1aehhjhg.xn--d1acj3b")
chekUrl(urlString:"http://www.example.com/wpstyle/?p=364")
chekUrl(urlString:"http://-.~_!$&'()*+,;=:%40:80%2f::::::#example.com")
chekUrl(urlString:"http://example.com")
chekUrl(urlString:"http://xn--d1acpjx3f.xn--p1ai")
chekUrl(urlString:"http://xn--74h.damowmow.com/")
chekUrl(urlString:"ftp://example.com:129/myfiles")
chekUrl(urlString:"ftp://user:pass#site.com:21/file/dir")
chekUrl(urlString:"ftp://ftp.example.com:2828/asdah%20asdah.gif")
chekUrl(urlString:"http://142.42.1.1:8080/")
chekUrl(urlString:"http://142.42.1.1/")
chekUrl(urlString:"http://userid:password#example.com:8080")
chekUrl(urlString:"http://userid#example.com")
chekUrl(urlString:"http://userid#example.com:8080")
chekUrl(urlString:"http://foo.com/blah_(wikipedia)#cite-1")
chekUrl(urlString:"http://foo.com/(something)?after=parens")
print("\n----------------------------------------------\n")
chekUrl(urlString:".")
chekUrl(urlString:" ")
chekUrl(urlString:"")
chekUrl(urlString:"-/:;()₽&#.,?!'{}[];'<>+_)(*#^%$")
chekUrl(urlString:"localhost")
chekUrl(urlString:"yandex.")
chekUrl(urlString:"коряга")
chekUrl(urlString:"http:///a")
chekUrl(urlString:"ftps://foo.bar/")
chekUrl(urlString:"rdar://1234")
chekUrl(urlString:"h://test")
chekUrl(urlString:":// should fail")
chekUrl(urlString:"http://-error-.invalid/")
chekUrl(urlString:"http://.www.example.com/")
}
func chekUrl(urlString: String) {
var result = ""
if urlString.isUrl {
result += "url: "
} else {
result += "not url: "
}
result += "\"\(urlString)\""
print(result)
}
Result
Objective C
- (BOOL)validateUrlString:(NSString*)urlString
{
if (!urlString)
{
return NO;
}
NSDataDetector *linkDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:nil];
NSRange urlStringRange = NSMakeRange(0, [urlString length]);
NSMatchingOptions matchingOptions = 0;
if (1 != [linkDetector numberOfMatchesInString:urlString options:matchingOptions range:urlStringRange])
{
return NO;
}
NSTextCheckingResult *checkingResult = [linkDetector firstMatchInString:urlString options:matchingOptions range:urlStringRange];
return checkingResult.resultType == NSTextCheckingTypeLink && NSEqualRanges(checkingResult.range, urlStringRange);
}
Hope this helps!
did you mean to check if what the user entered is a URL? It can be as simple as a regular expression, for example checking if the string contain www. (this is the way that yahoo messenger checks if the user status is a link or not)
Hope that help
Selfishly, I would suggest using a KSURLFormatter instance to both validate input, and convert it to something NSURL can handle.
I have created inherited class of UITextField which can handle all kind of validation using regex string. In this you just need to give them all the regex string in sequence and their message that you want to show when validation get failed. You can check my blog for more info, it will really help you
http://dhawaldawar.wordpress.com/2014/06/11/uitextfield-validation-ios/
Extending #Anthony's answer to swift, I wrote a category on String which returns an optional NSURL. The return value is nil if the String can not be validated to be a URL.
import Foundation
// A private global detector variable which can be reused.
private let detector = try! NSDataDetector(types: NSTextCheckingType.Link.rawValue)
extension String {
func URL() -> NSURL? {
let textRange = NSMakeRange(0, self.characters.count)
guard let URLResult = detector.firstMatchInString(self, options: [], range: textRange) else {
return nil
}
// This checks that the whole string is the detected URL. In case
// you don't have such a requirement, you can remove this code
// and return the URL from URLResult.
guard NSEqualRanges(URLResult.range, textRange) else {
return nil
}
return NSURL(string: self)
}
}
func checkValidUrl(_ strUrl: String) -> Bool {
let urlRegEx: String = "(http|https)://((\\w)*|([0-9]*)|([-|_])*)+([\\.|/]((\\w)*|([0-9]*)|([-|_])*))+"
let urlTest = NSPredicate(format: "SELF MATCHES %#", urlRegEx)
return urlTest.evaluate(with: strUrl)
}
My solution in Swift 5:
extension String {
func isValidUrl() -> Bool {
do {
let detector = try NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
// check if the string has link inside
return detector.numberOfMatches(in: self, options: [], range: .init( location: 0, length: utf16.count)) > 0
} catch {
print("Error during NSDatadetector initialization \(error)" )
}
return false
}
}