Regex to match spaces except for spaces inside url pattern

Question

Hi I'm new to regex and I am trying to use this to catch spaces \s{2,} in the junk but NOT including the spaces inside the "url":"https://x.com/a/C25/XPS - Connection - May 2013.docx". Currently, I have a scenario where url is not encoded yet so it may contain spaces inside.

Sample Text:

"startofjunk      junkjunkjunkjunk","url":"https://x.com/a/C25/XPS  - Connection - May 2013.docx","contentsource":"AX","returpath":null,"detailpath":"https://ax.sample.com/Rep>ositories/form.aspx?path=C25/96/99&mode=Read","detailspath2":"samplepath"

Desired Text:

"startofjunk junkjunkjunkjunk","url":"https://x.com/a/C25/XPS  - Connection - May 2013.docx","contentsource":"AX","returpath":null,"detailpath":"https://ax.sample.com/Rep>ositories/form.aspx?path=C25/96/99&mode=Read","detailspath2":"samplepath"

please help. Thanks

Answer 1

Description

This regex will find an replace all multiple spaces with a single space, and will bypass the url section. In a sequence of X number of spaces, the first space is placed into group 1 which is fed to the output as \1 and the additional spaces are ignored. The URL section is bypassed because if it is encountered as part of the | or statement, then it is captured into group 2 which is then injected back into the output by the \2 replacement.

Regex: (\s)\s*|("url":"[^"]*"), Replace with: \1\2

Source String

"startofjunk        junkjunkjunkjunk","url":"https://x.com/a/C25/XPS - Connection - May 2013.docx","contentsource":"AX","returpath":null,"detailpath":"https://ax.sample.com/Rep>ositories/form.aspx?path=C25/96/99&mode=Read","detailspath2":"samplepath"

PHP example

This php example is included to simply show that the regex works

<?php
$sourcestring="your source string";
echo preg_replace('/(\s)\s*|("url":"[^"]*")/im','\1',$sourcestring);
?>

$sourcestring after replacement:
"startofjunk junkjunkjunkjunk","url":"https://x.com/a/C25/XPS - Connection - May 2013.docx","contentsource":"AX","returpath":null,"detailpath":"https://ax.sample.com/Rep>ositories/form.aspx?path=C25/96/99&mode=Read","detailspath2":"samplepath"

Answer 2

Use a look-ahead to assert that your spaces occur before "url". Also use a look-behind so your whole match is the excess spaces:

(?<=\s)\s+(?=.*"url":)

To remove excess spaces, replace the entire match with blank (ie nothing), or if your application language allows it, remove the entire match.