Input:
Animal {cow.<span>moo</span>} <span>noises</span>
Output:
Animal {cow.moo} <span>noises</span>
How could I match only the <span> inside the braces for replacement? I have got as far as matching everything between the braces with
(?<=\{)(.*?)(?=\})
Any help would be greatly appreciated.
You may use a preg_replace_callback to match the strings in between {...} with a basic regex like '~{[^}]+}~' and then replace what you need inside the callback function:
$s = 'Animal {cow.<span>moo</span>} <span>noises</span>';
echo preg_replace_callback('~{[^}]+}~', function($m) {
return str_replace(["<span>", "</span>"], "", $m[0]);
}, $s);
// => Animal {cow.moo} <span>noises</span>
See the PHP demo.
You may use a preg_replace inside the callback function if you need to replace with a regex.
If you want to capture the moo inside the span for substitution you can use this regexp:
\{.*?\<span\>(.*)\<\/span\>\}
Here is an example: https://regex101.com/r/ryP3Y6/1
If you want to delete the <span> tags you can use:
(.*\{.*?)(?:\<[\/]?span\>)(.*)(?:<\/span\>)(\}.*)
And use \1\2\3 for substitution:
With a \G based pattern:
$str = preg_replace('~(?:\G(?!\A)|{)[^}]*?\K</?span>~', '', $str);
This pattern starts with two possible branches:
(?=[^}]*}) after it to ensure there's a closing bracket.\G that is the position after the last match.[^}]*? forbids to go out of the curly bracket enclosed substring.
This design ensures that all series of matches starting from a { are contiguous and that the <span> tags found are between curly brackets.
For small strings and if you are sure curly brackets are balanced and not nested, you can also use a more simple pattern:
$str = preg_replace('~</?span>(?=[^{}]*})~', '', $str);