Validate url with query string containing email address using PHP - php

Question

Hi I have problem with correct url validation with query string containing email address like:
https://example.com/?email=john+test1#example.com
this email is ofc correct one john+test1#example.com is an alias of john#example.com
I have regex like this:
$page = trim(preg_replace('/[\\0\\s+]/', '', $page));
but it don't work as I expected because it replaces + to empty string what is wrong. It should keep this + as alias of email address and should cut out special characters while maintaining the correctness of the address.
Example of wrong url with +:
https://examp+le.com/?email=example#exam+ple.com
Other urls without email in query string should be validating correctly using this regex
Any idea how to solve it?

Answer 1

I think this is what you looking for:
<?php
function replace_plus_sign($string){
return
preg_replace(
'/#/',
'+',
preg_replace(
'/\++/i',
'',
preg_replace_callback(
'/(email([\d]+)?=)([^#]+)/i',
function($matches){
return $matches[1] . preg_replace('/\+(?!$)/i', '#', $matches[3]);
},
$string
)
)
);
}
$page = 'https://exam+ple.com/email=john+test1+#example.com&email2=john+test2#exam+ple.com';
echo replace_plus_sign($page);
Gives the following output:
https://example.com/email=john+test1#example.com&email2=john+test2#example.com
At first, I replaced the valid + sign on email addresses with a #, then removing all the remainings +, after that, I replaced the # with +.
This solution won't work if there's a #s on the URL if so you will need to use another character instead of # for the temporary replacement.