I am using Kimono Labs to scrape a bunch of websites. I'd like to append "/critic-reviews" to the end of a url Kimono allows regex only in this format -
/^()(.*?)()$/
I have a bunch of URLs in this representative format -
http://www.metacritic.com/game/playstation-4/disney-infinity-30-edition
Try to add this function in "Modify results" :
function transform (data) {
function add_url(item) {
item.title.href += "/critic-reviews";
return item;
}
for (var collection in data.results) {
data.results[collection] = data.results[collection].map(add_url);
}
return data;
}
this seems to be one matching pattern?
http://www.metacritic.com/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)
http://regexone.com/lesson/kleene_operators gives you a walkthrough of how this works.
http://www.regextester.com/ and test your regex up there.
Related
I'm trying to extract the part of url (To be more specific, I'm trying to extract the value of page_info parameter in the url which is next to rel="next"
String testUrl = "<https://demo.myshopify.com/admin/api/2022-01/products.json?limit=10&page_info=eyJkaXJlY3Rpb24iOiJwcmV2IiwibGFzdF9pZCI6NjczMDU4MDcyMTc1NCwibGFzdF92YWx1ZSI6IjE4SyBHb2xkIFBsYXRlZCBCcmFjZWxldCJ9>; rel='previous', <https://demo.myshopify.com/admin/api/2022-01/products.json?limit=10&page_info=eyJkaXJlY3Rpb24iOiJuZXh0IiwibGFzdF9pZCI6NjczMDIyNzcxMjA5MCwibGFzdF92YWx1ZSI6IjE4SyBHb2xkIFBsYXRlZCBIZWFydCBQZW5kYW50IE5lY2tsYWNlIn0>; rel='next'";
List<String> splitUrl = testUrl.split("=");
print(splitUrl[5]);
// this is what it prints out
eyJkaXJlY3Rpb24iOiJuZXh0IiwibGFzdF9pZCI6NjczMDIyNzcxMjA5MCwibGFzdF92YWx1ZSI6IjE4SyBHb2xkIFBsYXRlZCBIZWFydCBQZW5kYW50IE5lY2tsYWNlIn0>; rel
// this is what I'm trying to extract
eyJkaXJlY3Rpb24iOiJuZXh0IiwibGFzdF9pZCI6NjczMDIyNzcxMjA5MCwibGFzdF92YWx1ZSI6IjE4SyBHb2xkIFBsYXRlZCBIZWFydCBQZW5kYW50IE5lY2tsYWNlIn0
// value for rel="next"
I tried to split the url by using split function on String but that would also bring the angle bracket with it. I'm trying to extract only page_info= parameter value which is for rel="next"
I know this has to do something with regex but I'm not really good at it! Any help would be really appreciated
I grabbed that url from header response (paginated REST API), it returns two page_info parameters (one for next and other one for previous page) I'm trying to extract value for next page. Splitting the url didn't help me
thank you
An alternative approach is to use Uri.parse to parse the URL:
void main() {
String testUrl = "<https://demo.myshopify.com/admin/api/2022-01/products.json?limit=10&page_info=eyJkaXJlY3Rpb24iOiJwcmV2IiwibGFzdF9pZCI6NjczMDU4MDcyMTc1NCwibGFzdF92YWx1ZSI6IjE4SyBHb2xkIFBsYXRlZCBCcmFjZWxldCJ9>; rel='previous', <https://demo.myshopify.com/admin/api/2022-01/products.json?limit=10&page_info=eyJkaXJlY3Rpb24iOiJuZXh0IiwibGFzdF9pZCI6NjczMDIyNzcxMjA5MCwibGFzdF92YWx1ZSI6IjE4SyBHb2xkIFBsYXRlZCBIZWFydCBQZW5kYW50IE5lY2tsYWNlIn0>; rel='next'";
// Extract just the URL.
var match = RegExp(r'<([^>]*)>').firstMatch(testUrl);
if (match != null) {
var uri = Uri.parse(match.group(1)!);
print(uri.queryParameters['page_info']); // Prints: eyJkaXJlY3Rpb24iOiJ...
}
}
Note that the above wouldn't need any of the RegExp code if testUrl were a proper URL without the angle brackets and rel='next' junk.
the regEx pattern page_info=([\w]+)
gives you
eyJkaXJlY3Rpb24iOiJwcmV2IiwibGFzdF9pZCI6NjczMDU4MDcyMTc1NCwibGFzdF92YWx1ZSI6IjE4SyBHb2xkIFBsYXRlZCBCcmFjZWxldCJ9
eyJkaXJlY3Rpb24iOiJuZXh0IiwibGFzdF9pZCI6NjczMDIyNzcxMjA5MCwibGFzdF92YWx1ZSI6IjE4SyBHb2xkIFBsYXRlZCBIZWFydCBQZW5kYW50IE5lY2tsYWNlIn0
https://regexr.com/6qj1h
Hello I want to extract JSON from below input string.
I have tried bellow regex in java and it is working fine,
private static final Pattern shortcode_media = Pattern.compile("\"shortcode_media\":(\\{.+\\})");
I want in regex for dart.
Input String
<script type="text/javascript">window.__initialDataLoaded(window._sharedData);</script><script type="text/javascript">window.__additionalDataLoaded('/p/B9fphP5gBeG/',{"graphql":{"shortcode_media":{"__typename":"GraphSidecar","id":"2260708142683789190","shortcode":"B9fphP5gBeG","dimensions":{"height":1326,"width":1080}}}});</script><script type="text/javascript">
<script type="text/javascript">window.__initialDataLoaded(window._newData);</script><script type="text/javascript">window._newData('/p/B9fphP5gBeG/',{"graphql":{"post":{"__typename":"id","id":"2260708142683789190","new_code":"B9fphP5gBeG"}}});</script><script type="text/javascript">
(function(){
function normalizeError(err) {
var errorInfo = err.error || {};
var getConfigProp = function(propName, defaultValueIfNotTruthy) {
var propValue = window._sharedData && window._sharedData[propName];
return propValue ? propValue : defaultValueIfNotTruthy;
};
return {}
}
)
Expected json
{"graphql":{"shortcode_media":{"__typename":"GraphSidecar","id":"2260708142683789190","shortcode":"B9fphP5gBeG","dimensions":{"height":1326,"width":1080}}}}
Note: There are multiple json string in input string, i need json of shortcode_media tag
please use
void main() {
String json = '''
{"graphql":
{"shortcode_media":{"__typename":"GraphSidecar","id":"2260708142683789190","shortcode":"B9fphP5gBeG","dimensions":{"height":1326,"width":1080}}},
"abc":{"def":"test"}
}
''';
RegExp regExp = new RegExp(
"\"shortcode_media\":(\\{.+\\})",
caseSensitive: false,
multiLine: false,
);
print(regExp.stringMatch(json).toString());
}
output
"shortcode_media":{"__typename":"GraphSidecar","id":"2260708142683789190","shortcode":"B9fphP5gBeG","dimensions":{"height":1326,"width":1080}}}
Dartpad
The corresponding Dart RegExp would be:
static final RegExp shortcodeMedia = RegExp(r'"shortcode_media":(\{.+\})");
It does not work, though. JSON is not a regular language, so you can't parse it using regular expressions.
The value of "shortcode_media" in your example JSON ends with several } characters. The RegExp will stop the match at the third of those, even though the second } is the one matching the leading {. If your JSON text contains any further values after the shortcode_media entry, those might be included as well.
Stopping at the first } would also be too short.
If someone reorders the JSON source code to the equivalent
"shortcode_media":{"dimensions":{"height":1326,"width":1080},"__typename":"GraphSidecar","id":"2260708142683789190","shortcode":"B9fphP5gBeG"}
(that is, putting the "dimensions" entry first), then you would only capture until the end of the dimensions block.
I would recommend either using a proper JSON parser, or at least improving the RegExp to be able to handle a single nested JSON object - since you seem to already know that it will happen.
Such a RegExp could be:
RegExp(r'"shortcode_media":(\{(?:[^{}]*(?:\{.*?\})?)*?\})')
This RegExp will capture the correct number of braces for the example code, but still won't work if there are more nested JSON objects. Only a real parser can handle the general case correctly.
I would like to have a pipe which is detecting any url in a string and creating a link with it. At the moment I created this, which seems not working:
#Pipe({name:'matchUrl'})
export class MatchUrlPipe implements PipeTransform {
transform(value: string, arg?: any): any {
var exp = /https?:\/\/(www\.)?[-a-zA-Z0-9#:%._\+~#=]{2,256}\.[a-z]{2,4}\b([-a-zA-Z0-9#:%_\+.~#?&//=]*)/g;
return value.replace(exp, "<a href='$1'>$1</a>");
}
}
How can I fix it?
Seems like there are two problems with your implementation:
Your regex has the first capturing group ( $1 ) matching the 'www' part of the url. You want to change the regex like this for it to work (note the extra pair of parethesis at the start and end of the regex):
var exp = /(https?:\/\/(www\.)?[-a-zA-Z0-9#:%._\+~#=]{2,256}\.[a-z]{2,4}\b([-a-zA-Z0-9#:%_\+.~#?&//=]*))/g;
Pipes can't render html normally. You need a trick to do that as mentioned in other questione like this. You need to assign your 'piped value' to the attribute outerHTML of a span for example (the span will not be rendered).
Plunker example
Does someone have a regular expression that gets a link to a Youtube video (not embedded object) from (almost) all the possible ways of linking to Youtube?
I think this is a pretty common problem and I'm sure there are a lot of ways to link that.
A starting point would be:
http://www.youtube.com/watch?v=iwGFalTRHDA
http://www.youtube.com/watch?v=iwGFalTRHDA&feature=related
http://youtu.be/iwGFalTRHDA
http://youtu.be/n17B_uFF4cA
http://www.youtube.com/embed/watch?feature=player_embedded&v=r5nB9u4jjy4
http://www.youtube.com/watch?v=t-ZRX8984sc
http://youtu.be/t-ZRX8984sc
... please add more possible links and/or regular expressions to detect them.
So far I got this Regular expression working for the examples I posted, and it gets the ID on the first group:
http(?:s?):\/\/(?:www\.)?youtu(?:be\.com\/watch\?v=|\.be\/)([\w\-\_]*)(&(amp;)?[\w\?=]*)?
You can use this expression below.
(?:https?:\/\/)?(?:www\.)?youtu\.?be(?:\.com)?\/?.*(?:watch|embed)?(?:.*v=|v\/|\/)([\w\-_]+)\&?
I'm using it, and it cover the most used URLs.
I'll keep updating it on This Gist.
You can test it on this tool.
I like #brunodles's solution the most but you can still match non video links like https://www.youtube.com/feed/subscriptions
I went with this solution
(?:https?:\/\/)?(?:www\.)?youtu(?:\.be\/|be.com\/\S*(?:watch|embed)(?:(?:(?=\/[-a-zA-Z0-9_]{11,}(?!\S))\/)|(?:\S*v=|v\/)))([-a-zA-Z0-9_]{11,})
It can also be used to match multiple whitespace separated links.
The video id will be captured in the first group.
Tested with the following urls:
youtu.be/iwGFalTRHDA
youtube.com/watch?v=iwGFalTRHDA
www.youtube.com/watch?v=iwGFalTRHDA
http://www.youtube.com/watch?v=iwGFalTRHDA
https://www.youtube.com/watch?v=iwGFalTRHDA
https://www.youtube.com/watch?v=MoBL33GT9S8&feature=share
https://www.youtube.com/embed/watch?feature=player_embedded&v=iwGFalTRHDA
https://www.youtube.com/embed/watch?v=iwGFalTRHDA
https://www.youtube.com/embed/v=iwGFalTRHDA
https://www.youtube.com/watch/iwGFalTRHDA
http://www.youtube.com/attribution_link?u=/watch?v=aGmiw_rrNxk&feature=share
https://m.youtube.com/watch?v=iwGFalTRHDA
// will not match
https://www.youtube.com/feed/subscriptions
https://www.youtube.com/channel/UCgc00bfF_PvO_2AvqJZHXFg
https://www.youtube.com/c/NatGeoEdOrg/videos
https://regex101.com/r/rq2KLv/1
I improved the links posted above with a friend for a script I wrote for IRC to recognize even links without http at all. It worked on all stress tests I got so far, including garbled text with barely recognizable youtube urls, so here it is:
~(?:https?://)?(?:www\.)?youtu(?:be\.com/watch\?(?:.*?&(?:amp;)?)?v=|\.be/)([\w\-]+)(?:&(?:amp;)?[\w\?=]*)?~
I testet all the regular expressions that are shown here and none could cover all url types that my client was using.
I built this pretty much through trial and error, but it seems to work with all the patterns that Poppy Deejay posted.
"(?:.+?)?(?:\/v\/|watch\/|\?v=|\&v=|youtu\.be\/|\/v=|^youtu\.be\/)([a-zA-Z0-9_-]{11})+"
Maybe it helps someone who is in a similar situation that I had today ;)
Piggy backing on Fanmade, this covers the below links including the url encoded version of attribution_links:
(?:.+?)?(?:\/v\/|watch\/|\?v=|\&v=|youtu\.be\/|\/v=|^youtu\.be\/|watch\%3Fv\%3D)([a-zA-Z0-9_-]{11})+
https://www.youtube.com/attribution_link?a=tolCzpA7CrY&u=%2Fwatch%3Fv%3DMoBL33GT9S8%26feature%3Dshare
https://www.youtube.com/watch?v=MoBL33GT9S8&feature=share
http://www.youtube.com/watch?v=iwGFalTRHDA
https://www.youtube.com/watch?v=iwGFalTRHDA
http://www.youtube.com/watch?v=iwGFalTRHDA&feature=related
http://youtu.be/iwGFalTRHDA
http://www.youtube.com/embed/watch?feature=player_embedded&v=iwGFalTRHDA
http://www.youtube.com/embed/watch?v=iwGFalTRHDA
http://www.youtube.com/embed/v=iwGFalTRHDA
http://www.youtube.com/watch?feature=player_embedded&v=iwGFalTRHDA
http://www.youtube.com/watch?v=iwGFalTRHDA
www.youtube.com/watch?v=iwGFalTRHDA
www.youtu.be/iwGFalTRHDA
youtu.be/iwGFalTRHDA
youtube.com/watch?v=iwGFalTRHDA
http://www.youtube.com/watch/iwGFalTRHDA
http://www.youtube.com/v/iwGFalTRHDA
http://www.youtube.com/v/i_GFalTRHDA
http://www.youtube.com/watch?v=i-GFalTRHDA&feature=related
http://www.youtube.com/attribution_link?u=/watch?v=aGmiw_rrNxk&feature=share&a=9QlmP1yvjcllp0h3l0NwuA
http://www.youtube.com/attribution_link?a=fF1CWYwxCQ4&u=/watch?v=qYr8opTPSaQ&feature=em-uploademail
http://www.youtube.com/attribution_link?a=fF1CWYwxCQ4&feature=em-uploademail&u=/watch?v=qYr8opTPSaQ
I've been having problems lately with the atttribution_link urls so i tried making my own regex that works for those too.
Here is my regex string:
(https?://)?(www\\.)?(yotu\\.be/|youtube\\.com/)?((.+/)?(watch(\\?v=|.+&v=))?(v=)?)([\\w_-]{11})(&.+)?
and here are some test cases i've tried:
http://www.youtube.com/watch?v=iwGFalTRHDA
https://www.youtube.com/watch?v=iwGFalTRHDA
http://www.youtube.com/watch?v=iwGFalTRHDA&feature=related
http://youtu.be/iwGFalTRHDA
http://www.youtube.com/embed/watch?feature=player_embedded&v=iwGFalTRHDA
http://www.youtube.com/embed/watch?v=iwGFalTRHDA
http://www.youtube.com/embed/v=iwGFalTRHDA
http://www.youtube.com/watch?feature=player_embedded&v=iwGFalTRHDA
http://www.youtube.com/watch?v=iwGFalTRHDA
www.youtube.com/watch?v=iwGFalTRHDA
www.youtu.be/iwGFalTRHDA
youtu.be/iwGFalTRHDA
youtube.com/watch?v=iwGFalTRHDA
http://www.youtube.com/watch/iwGFalTRHDA
http://www.youtube.com/v/iwGFalTRHDA
http://www.youtube.com/v/i_GFalTRHDA
http://www.youtube.com/watch?v=i-GFalTRHDA&feature=related
http://www.youtube.com/attribution_link?u=/watch?v=aGmiw_rrNxk&feature=share&a=9QlmP1yvjcllp0h3l0NwuA
http://www.youtube.com/attribution_link?a=fF1CWYwxCQ4&u=/watch?v=qYr8opTPSaQ&feature=em-uploademail
http://www.youtube.com/attribution_link?a=fF1CWYwxCQ4&feature=em-uploademail&u=/watch?v=qYr8opTPSaQ
Also remember to check the string you get for your video url, sometimes it may get the percent characters. If so just do this
url = [url stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
and it should fix it.
Remember also that the index of the youtube key is now index 9.
NSRange youtubeKey = [result rangeAtIndex:9]; //the youtube key
NSString * strKey = [url substringWithRange:youtubeKey] ;
It'd be the longest RegEx in the world if you managed to cover all link formats, but here's one to get you started which will cover the first couple of link formats:
http://(www\.)?youtube\.com/watch\?.*v=([a-zA-Z0-9]+).*
The second group will match the video ID if you need to get that out.
(?:http?s?:\/\/)?(?:www.)?(?:m.)?(?:music.)?youtu(?:\.?be)(?:\.com)?(?:(?:\w*.?:\/\/)?\w*.?\w*-?.?\w*\/(?:embed|e|v|watch|.*\/)?\??(?:feature=\w*\.?\w*)?&?(?:v=)?\/?)([\w\d_-]{11})(?:\S+)?
https://regex101.com/r/nJzgG0/3
Detects YouTube and YouTube Music link in any string
I took all variants from here:
https://gist.github.com/rodrigoborgesdeoliveira/987683cfbfcc8d800192da1e73adc486#file-youtubeurlformats-txt
And built this regexp (YouTube ID is in group 2):
(\/|%3D|v=|vi=)([0-9A-z-_]{11})[%#?&\s]
Check it here: https://regexr.com/4u4ud
Edit: Works for any single string w/o breaks.
I'm working with that kind of links:
http://www.youtube.com/v/M-faNJWc9T0?fs=1&rel=0
And here's the regEx I'm using to get ID from it:
"(.+?)(\/v/)([a-zA-Z0-9_-]{11})+"
This is iterating on the existing answers and handles edge cases better. (for example http://thisisnotyoutu.be/thing)
/(?:https?:\/\/|www\.|m\.|^)youtu(?:be\.com\/watch\?(?:.*?&(?:amp;)?)?v=|\.be\/)([\w\-]+)(?:&(?:amp;)?[\w\?=]*)?/
here is the complete solution for getting youtube video id for java or android, i didn't found any link which doesn't work with this function
public static String getValidYoutubeVideoId(String youtubeUrl)
{
if(youtubeUrl == null || youtubeUrl.trim().contentEquals(""))
{
return "";
}
youtubeUrl = youtubeUrl.trim();
String validYoutubeVideoId = "";
String regexPattern = "^(?:https?:\\/\\/)?(?:[0-9A-Z-]+\\.)?(?:youtu\\.be\\/|youtube\\.com\\S*[^\\w\\-\\s])([\\w\\-]{11})(?=[^\\w\\-]|$)(?![?=&+%\\w]*(?:['\"][^<>]*>|<\\/a>))[?=&+%\\w]*";
Pattern regexCompiled = Pattern.compile(regexPattern, Pattern.CASE_INSENSITIVE);
Matcher regexMatcher = regexCompiled.matcher(youtubeUrl);
if(regexMatcher.find())
{
try
{
validYoutubeVideoId = regexMatcher.group(1);
}
catch(Exception ex)
{
}
}
return validYoutubeVideoId;
}
This is my answer to use in Scala. This is useful to extract 11 digits from Youtube's URL.
"https?://(?:[0-9a-zA-Z-]+.)?(?:www.youtube.com/|youtu.be\S*[^\w-\s])([\w -]{11})(?=[^\w-]|$)(?![?=&+%\w](?:[\'"][^<>]>|))[?=&+%\w-]*"
def getVideoLinkWR: UserDefinedFunction = udf(f = (videoLink: String) => {
val youtubeRgx = """https?://(?:[0-9a-zA-Z-]+\.)?(?:youtu\.be/|youtube\.com\S*[^\w\-\s])([\w \-]{11})(?=[^\w\-]|$)(?![?=&+%\w]*(?:[\'"][^<>]*>|</a>))[?=&+%\w-./]*""".r
videoLink match {
case youtubeRgx(a) => s"$a".toString
case _ => videoLink.toString
}
}
Youtube video URL Change to iframe supported link:
REGEX: https://regex101.com/r/LeZ9WH/2/
http://www.youtube.com/watch?v=iwGFalTRHDA
http://www.youtube.com/watch?v=iwGFalTRHDA&feature=related
http://youtu.be/iwGFalTRHDA
http://youtu.be/n17B_uFF4cA
http://www.youtube.com/embed/watch?feature=player_embedded&v=r5nB9u4jjy4
http://www.youtube.com/watch?v=t-ZRX8984sc
http://youtu.be/t-ZRX8984sc
https://youtu.be/2sFlFPmUfNo?t=1
Php function example:
if (!function_exists('clean_youtube_link')) {
/**
* #param $link
* #return string|string[]|null
*/
function clean_youtube_link($link)
{
return preg_replace(
'#(.+?)(\/)(watch\x3Fv=)?(embed\/watch\x3Ffeature\=player_embedded\x26v=)?([a-zA-Z0-9_-]{11})+#',
"https://www.youtube.com/embed/$5",
$link
);
}
}
This should work for almost all youtube links when extracting from a string:
((?:https?:)?\/\/)?((?:www|m)\.)?((?:youtube\.com|youtu.be))(\/(?:[\w\-]+\?v=|embed\/|v\/)?)([\w\-]{10}).\b
var isValidYoutubeLink: Bool{
// working for all the youtube url's
NSPredicate(format: "SELF MATCHES %#", "(?:http?s?:\\/\\/)?(?:www.)?(?:m.)?(?:music.)?youtu(?:\\.?be)(?:\\.com)?(?:(?:\\w*.?:\\/\\/)?\\w*.?\\w*-?.?\\w*\\/(?:embed|e|v|watch|.*\\/)?\\??(?:feature=\\w*\\.?\\w*)?&?(?:v=)?\\/?)([\\w\\d_-]{11})(?:\\S+)?").evaluate(with: self)
}
With this Javascript Regex, the first capture is a video ID :
^(?:https?:)?(?:\/\/)?(?:www\.)?(?:youtu\.be\/|youtube(?:\-nocookie)?\.(?:[A-Za-z]{2,4}|[A-Za-z]{2,3}\.[A-Za-z]{2})\/)(?:watch|embed\/|vi?\/)*(?:\?[\w=&]*vi?=)?([^#&\?\/]{11}).*$
(?-s)^https?\W+(?:www\.|m\.|music\.)*youtu\.?be(?:\.com|\/watch|\/o?embed|\/shorts|\/attribution_link\?[&\w\-=]*[au]=|\/ytsc\w+|[\?&\/]+[ve]i?\b|\?feature=\w+|-nocookie)*[\/=]([a-z\d\-_]{11})[\?&#% \t ] *.*$
or
(?-s)^(?:(?!https?[:\/]|www\.|m\.yo|music\.yo|youtu\.?be[\/\.]|watch[\/\?]|embed\/)\V)*(?:https?[:\/]+|www\.|m\.|music\.)+youtu\.?be(?:\.com\/|watch|o?embed(?:\/|\?url=\S+?)?|shorts|attribution_link\?[&\w\-=]*[au]=\/?|ytsc\w+|[\?&]*[ve]i?\b|\?feature=\w+|[\?&]time_continue=\d+|-nocookie|%[23][56FD])*(?:[\/=]|%2F|%3D)([a-z\d\-_]{11})[\?&#% \t ]? *.*$
(the part >>#% \t⠀ ]<< should contain continuous space, which is Alt+255, but stackoverflow-com can't print it)
(this string may be replaced to \1, sorted and abbreviated with: )
V█(?-i)^([A-Za-z\d\-_]{11})(?:\v+\1)*$
>█https:\/\/youtu\.be\/\1
(./dot can take up any symbol; \V or [^\r\n] can any except special, emoji and others; this >> [^!-⠀：／‽｜\s] << can grab some emoji)
https://youtu.be/x26ANNC3C-8 • ♾ 𝕳𝕰𝕽𝕰𝕿𝕳𝕰𝖄𝕮𝕺𝕸𝕰 - 𝔩𝔢𝔞𝔳𝔢 𝔪𝔢 𝔞𝔩𝔬𝔫𝔢 • 7:15
This regex solve my problem, I can get youtube link having watch, embed or shared link
(?:http(?:s)?:\/\/)?(?:www\.)?(?:youtu\.be\/|youtube\.com\/(?:(?:watch)?\?(?:.*&)?v(?:i)?=|(?:embed|v|vi|user)\/))([^\?&\"'<> #]+)
You can check here https://regex101.com/r/Kvk0nB/1
I have a HTML with the following content:
... some text ...
link ... some text ...
... some text ...
link ... some text ...
... some text ...
I would like to parse that and get a match with named groups:
match 1
group["user"]=123
group["section"]=2
match 2
group["user"]=678
group["section"]=5
I can do it if parameters always go in order, first User and then Section, but I don't know how to do it if the order is different.
Thank you!
In my case I had to parse an Url because the utility HttpUtility.ParseQueryString is not available in WP7. So, I created a extension method like this:
public static class UriExtensions
{
private static readonly Regex queryStringRegex;
static UriExtensions()
{
queryStringRegex = new Regex(#"[\?&](?<name>[^&=]+)=(?<value>[^&=]+)");
}
public static IEnumerable<KeyValuePair<string, string>> ParseQueryString(this Uri uri)
{
if (uri == null)
throw new ArgumentException("uri");
var matches = queryStringRegex.Matches(uri.OriginalString);
for (int i = 0; i < matches.Count; i++)
{
var match = matches[i];
yield return new KeyValuePair<string, string>(match.Groups["name"].Value, match.Groups["value"].Value);
}
}
}
Then It's matter of using it, for example
var uri = new Uri(HttpUtility.UrlDecode(#"file.aspx?userId=123§ion=2"),UriKind.RelativeOrAbsolute);
var parameters = uri.ParseQueryString().ToDictionary( kvp => kvp.Key, kvp => kvp.Value);
var userId = parameters["userId"];
var section = parameters["section"];
NOTE: I'm returning the IEnumerable instead of the dictionary directly just because I'm assuming that there might be duplicated parameter's name. If there are duplicated names, then the dictionary will throw an exception.
Why use regex to split it out?
You could first extrct the query string. Split the result on & and then create a map by splitting the result from that on =
You didn't specify what language you are working in, but this should do the trick in C#:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
namespace RegexTest
{
class Program
{
static void Main(string[] args)
{
string subjectString = #"... some text ...
link ... some text ...
... some text ...
link ... some text ...
... some text ...";
Regex regexObj =
new Regex(#"<a href=""file.aspx\?(?:(?:userId=(?<user>.+?)§ion=(?<section>.+?)"")|(?:section=(?<section>.+?)&user=(?<user>.+?)""))");
Match matchResults = regexObj.Match(subjectString);
while (matchResults.Success)
{
string user = matchResults.Groups["user"].Value;
string section = matchResults.Groups["section"].Value;
Console.WriteLine(string.Format("User = {0}, Section = {1}", user, section));
matchResults = matchResults.NextMatch();
}
Console.ReadKey();
}
}
}
Using regex to first find the key value pairs and then doing splits... doesn't seem right.
I'm interested in a complete regex solution.
Anyone?
Check this out
\<a\s+href\s*=\s*["'](?<baseUri>.+?)\?(?:(?<key>.+?)=(?<value>.+?)[&"'])*\s*\>
You can get pairs with something like Groups["key"].Captures[i] & Groups["value"].Captures[i]
Perhaps something like this (I am rusty on regex, and wasn't good at them in the first place anyway. Untested):
/href="[^?]*([?&](userId=(?<user>\d+))|section=(?<section>\d+))*"/
(By the way, the XHTML is malformed; & should be & in the attributes.)
Another approach is to put the capturing groups inside lookaheads:
Regex r = new Regex(#"<a href=""file\.aspx\?" +
#"(?=[^""<>]*?user=(?<user>\w+))" +
#"(?=[^""<>]*?section=(?<section>\w+))";
If there are only two parameters, there's no reason to prefer this way over the alternation-based approaches suggested by Mike and strager. But if you needed to match three parameters, the other regexes would grow to several times their current length, while this one would only need another lookahead like just like the two existing ones.
By the way, contrary to your response to Claus, it matters quite a bit which language you're working in. There's a huge variation in capabilities, syntax, and API from one language to the next.
You did not say which regex flavor you are using. Since your sample URL links to an .aspx file, I'll assume .NET. In .NET, a single regex can have multiple named capturing groups with the same name, and .NET will treat them as if they were one group. Thus you can use the regex
userID=(?<user>\d+)§ion=(?<section>\d+)|section=(?<section>\d+)&userID=(?<user>\d+)
This simple regex with alternation will be far more efficient than any tricks with lookaround. You can easily expand it if your requirements include matching the parameters only if they're in a link.
a simple python implementation overcoming the ordering problem
In [2]: x = re.compile('(?:(userId|section)=(\d+))+')
In [3]: t = 'href="file.aspx?section=2&userId=123"'
In [4]: x.findall(t)
Out[4]: [('section', '2'), ('userId', '123')]
In [5]: t = 'href="file.aspx?userId=123§ion=2"'
In [6]: x.findall(t)
Out[6]: [('userId', '123'), ('section', '2')]