CODEWITHSUNDEEP
javascriptregexregex-replace
inhwrbp
inhwrbp

Reputation: 609

Regex replace last part of url path if condition matches?

I am basically trying to remove the last part of a URL if the URL contains the path /ice/flag/. Example:

Input:

https://test.com/plants/ice/flag/237468372912873

Desired Output:

Because the above URL has /ice/flag/ in its path, I want the last part of the URL to be replaced with redacted.

https://test.com/plants/ice/flag/redacted

However, if the URL did not have /ice/flag (ex: https://test.com/plants/not_ice/flag/237468372912873), it shouldn't be replaced.

What I tried to do is to use the answer mentioned here to change the last part of the path:

var url = 'https://test.com/plants/ice/flag/237468372912873'
url = url.replace(/\/[^\/]*$/, '/redacted')

This works in doing the replacement, but I am unsure how to modify this so that it only matches if /ice/flag is in the path. I tried putting \/ice\/flag in certain parts of the regex to change the behavior to only replace if that is in the string, but nothing has been working. Any tips from those more experienced with regex on how to do this would be greatly appreciated, thank you!

Edit: The URL can be formed in different ways, so there may be other paths before or after /ice/flag/. So all of these are possibilities:

Input:

Desired Output:

Upvotes: 1

Views: 836

Answers (3)

anubhava
anubhava

Reputation: 785156

You may search for this regex:

(\/ice\/flag\/(?:[^?#]*\/)?)[^\/#?]+

and replace it with:

$1redacted

RegEx Demo

RegEx Breakup:

  • (: Start capture group #1
    • \/ice\/flag\/: Match /ice/flag/
    • (?:[^?#]*\/)?: Match 0 or more of any char that is not # and ? followed by a / as an optional match
  • ): End capture group #1
  • [^\/#?]+ Match 1+ of any char that is not / and # and ?

Code:

var arr = [
    'https://test.com/plants/ice/flag/237468372912873', 
    'https://test.com/plants/ice/flag/a/b/237468372912873',
    'https://test.com/a/ice/flag/e/237468372912873?p=2/12#aHash',
    'https://test.com/plants/not_ice/flag/237468372912873'];

var rx = /(\/ice\/flag\/(?:[^?#\n]*\/)?)[^\/#?\n]+/;
var subst = '$1redacted';

arr.forEach(el => console.log(el.replace(rx, subst)));

Upvotes: 2

Peter Thoeny
Peter Thoeny

Reputation: 7616

Here is functional code with test input strings based on your requirements:

const input = [
  'https://test.com/plants/ice/flag/237468372912873',
  'https://test.com/plants/extra/ice/flag/237468372912873',
  'https://test.com/plants/ice/flag/extra/237468372912873',
  'https://test.com/plants/ice/flag/extra/extra/237468372912873',
  'https://test.com/plants/ice/flag/extra/237468372912873#someHash',
  'https://test.com/plants/ice/flag/extra/237468372912873?paramOne=1&paramTwo=2#someHash',
  'https://test.com/plants/not_ice/flag/237468372912873'
];
const re = /(\/ice\/flag\/([^\/#?]+\/)*)[^\/#?]+/;

input.forEach(str => {
  console.log('str: ' + str + '\n  => ' + str.replace(re, '$1redacted'));
});

Output:

str: https://test.com/plants/ice/flag/237468372912873
  => https://test.com/plants/ice/flag/redacted
str: https://test.com/plants/extra/ice/flag/237468372912873
  => https://test.com/plants/extra/ice/flag/redacted
str: https://test.com/plants/ice/flag/extra/237468372912873
  => https://test.com/plants/ice/flag/extra/redacted
str: https://test.com/plants/ice/flag/extra/extra/237468372912873
  => https://test.com/plants/ice/flag/extra/extra/redacted
str: https://test.com/plants/ice/flag/extra/237468372912873#someHash
  => https://test.com/plants/ice/flag/extra/redacted#someHash
str: https://test.com/plants/ice/flag/extra/237468372912873?paramOne=1&paramTwo=2#someHash
  => https://test.com/plants/ice/flag/extra/redacted?paramOne=1&paramTwo=2#someHash
str: https://test.com/plants/not_ice/flag/237468372912873
  => https://test.com/plants/not_ice/flag/237468372912873

Regex:

  • ( - capture group start
  • \/ice\/flag\/ - expect /ice/flag/
  • ([^\/#?]+\/)* - zero or more patterns of chars other than /, #, ?, followed by /
  • ) - capture group end
  • [^\/#?]+ - discard anything that is not /, #, ? but expect at least one char (this will force stuff after the last /)

Upvotes: 1

Mina
Mina

Reputation: 17149

You can add a ternary operation condition to check if the url includes /ice/flag by url.includes('/ice/flag'), then replace url.replace(/\/[^\/]*$/, '/redacted') else return the url as it is.

function replace(url) {
  return url.includes('/ice/flag') ? url.replace(/\/[^\/]*$/, '/redacted') : url;
}

console.log(replace("https://test.com/plants/ice/flag/237468372912873"))
console.log(replace("https://test.com/plants/not_ice/flag/237468372912873"));

Upvotes: 0

Related Questions