Regex to remove all except XML - regex

Question

I need help with a Regex for notepad++ to match all but XML
The regex I'm using:
(!?\<.*\>) <-- I want the opposite of this (in first three lines)
The example code:
[20173003] This text is what I want to delete [<Person><Name>Foo</Name><Surname>Bar</Surname></Person>], and this text too.
[20173003] This is another text to delete [<Person><Name>Bar</Name><Surname>Foo</Surname></Person>]
[20173003] This text too... [<Person><Name>Lorem</Name><Surname>Ipsum</Surname></Person>], delete me!
[20173003] But things like this make the regex to fail < [<Person><Name>Lorem</Name><Surname>Ipsum</Surname></Person>], or this>
Expected result:
<Person><Name>Foo</Name><Surname>Bar</Surname></Person>
<Person><Name>Bar</Name><Surname>Foo</Surname></Person>
<Person><Name>Lorem</Name><Surname>Ipsum</Surname></Person>
<Person><Name>Lorem</Name><Surname>Ipsum</Surname></Person>
Thanks in advance!

Answer 1

This is not perfect, but should work with your input that looks quite simple and well-structured.
If you need to handle just a single unnested <Person> tag, you may use simple (<Person>.*?</Person>)|. regex (that will match and capture into Group 1 any <Person> tag and will match any other char) and replace with a conditional replacement pattern (?{1}$1\n:) (that will reinsert Person tag with a newline after it or will replace the match with an empty string):
To make it a bit more generic, you may capture the opening and corresponding closing XML tags with a recursion-based Boost regex, and the appropriate conditional replacement pattern:
Find What: (<(\w+)[^>]*>(?:(?!</?\2\b).|(?1))*</\2>)|.
Replace With: (?{1}$1\n:)
. matches newline: ON
Regex Details:
(<(\w+)[^>]*>(?:(?!</?\2\b).|(?1))*</\2>) - Capturing group 1 (that will be later recursed with the (?1) subrouting call) matching
<(\w+)[^>]*> - any opening tag with its name captured into Group 2
(?:(?!</?\2\b).|(?1))* - zero or more occurrences of:
(?!</?\2\b). - any char (.) not starting a sequence of </ + tag name as a whole word with an optional / in front
| - or
(?1) - the whole Group 1 subpattern is recursed (repeated)
</\2> - the corresponding closing tag
| - or
. - any single char.
Replacement pattern:
(?{1} - if Group 1 matches:
$1\n - replace with its contents + a newline
: - else replace with an empty string
) - end of the replacement pattern.