Flutter Dart: RegEx to extract URLs from a String

Question

This is my string:

    window.urlVideo = 'https://node34.vidstreamcdn.com/hls/5d59908aea5aa101a054dec2a1cd3aff/5d59908aea5aa101a054dec2a1cd3aff.playlist.m3u8';
var playerInstance = jwplayer("myVideo");
var countplayer = 1;
var countcheck = 0;
playerInstance.setup({
    sources: [{
        "file": urlVideo
    }],
    tracks: [{
        file: "https://cache.cdnfile.info/images/13f9ddcaf2d83d846056ec44b0f1366d/12.vtt",
        kind: "thumbnails"
    }],
    image: "https://cache.cdnfile.info/images/13f9ddcaf2d83d846056ec44b0f1366d/12_cover.jpg",
});

function changeLink() {
    window.location = "//vidstreaming.io/load.php?id=MTM0OTgz&title=Mairimashita%21+Iruma-kun+Episode+12";
}
window.shouldChangeLink = function () {
    window.location = "//vidstreaming.io/load.php?id=MTM0OTgz&title=Mairimashita%21+Iruma-kun+Episode+12";
}

I am using flutter dart.

How can I get window.urlVideo URL link and image URL link and .vtt file link?

Or

How can I get a list of URLs from a String? I tried finding a way with and without using RegEx but I couldn't.

Any help is apreciated

Solution 1

This may not be the complete regex, but this worked for me for randomly picked links:

void main() {
  final text = """My website url: https://blasanka.github.io/
Google search using: www.google.com, social media is facebook.com, http://example.com/method?param=flutter
stackoverflow.com is my greatest website. DartPad share: https://github.com/dart-lang/dart-pad/wiki/Sharing-Guide see this example and edit it here https://dartpad.dev/3d547fa15849f9794b7dbb8627499b00""";

  RegExp exp = new RegExp(r'(?:(?:https?|ftp):\/\/)?[\w/\-?=%.]+\.[\w/\-?=%.]+');
  Iterable<RegExpMatch> matches = exp.allMatches(text);

  matches.forEach((match) {
    print(text.substring(match.start, match.end));
  });
}

Result:

https://blasanka.github.io/
www.google.com
facebook.com
http://example.com/method?param=flutter
stackoverflow.com
https://github.com/dart-lang/dart-pad/wiki/Sharing-Guide
https://dartpad.dev/3d547fa15849f9794b7dbb8627499b00

Play with it here: https://dartpad.dev/3d547fa15849f9794b7dbb8627499b00

Solution 2

Try this,

final urlRegExp = new RegExp(
    r"((https?:www\.)|(https?:\/\/)|(www\.))[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9]{1,6}(\/[-a-zA-Z0-9()@:%_\+.~#?&\/=]*)?");
final urlMatches = urlRegExp.allMatches(text);
List<String> urls = urlMatches.map(
        (urlMatch) => text.substring(urlMatch.start, urlMatch.end))
    .toList();
urls.forEach((x) => print(x));

Solution 3

Much safer to use a library like linkify instead of rolling your own regex.

/// Attempts to extract link from a string.
///
/// If no link is found, then return null.
String extractLink(String input) {
  var elements = linkify(input,
      options: LinkifyOptions(
        humanize: false,
      ));
  for (var e in elements) {
    if (e is LinkableElement) {
      return e.url;
    }
  }
  return null;
}

Comments

[Her0Her0]

Linkify uses the following regex right now: r'^(.*?)((?:https?:\/\/|www\.)[^\s/$.?#].[^\s]*)'. Based on my testing at https://regexr.com/3e6m0, this matches https://google..............totallyrealurl,ofcourse!?

[CHRIS LEE]

This should be marked as the correct answer!

[Kamlesh]

I have a String Made by https://cretezy.com and Expected output: Made by <a href="https://cretezy.com">https://cretezy.com</a>. Kindly suggest me how can we do this? Thanks a lot.

[Kamlesh]

Not worked for me. I have a string which has https://support.google.com/firebase?authuser=0#topic=6399725 url and your solution converts it to like https://support.google.com/firebase?authuser=0 ignoring hash and further text string #topic=6399725. Kindly suggest how can we solve it. Thanks a lot.

[Kamlesh]

Thank you so much dear, your solution worked for me perfectly :)

[Blasanka]

@Kamlesh you can add any special char you want to the reg expression as mentioned in above comments. Based on the special char you may have to use escape character

[Kamlesh]

Thanks @Blasanka for your reply. This solution worked perfectly for me - stackoverflow.com/a/59445736/10329023