PHP preg_match_all - extract content from pattern in different order

I'm cleaning up some wordpress short codes in my code and I'm looking for a solution that would extract the right values no matter the order of the values.

Example:

[Links label="my_label" url="my_url" external="other_value"]

If I want to extract my_label, my_url and other_value, I would use the following structure:

preg_match_all('/\[Links label=\"(.*?)\" url=\"(.*?)\" external=\"(.*?)\"\]/', $content, $output_array);

The problem is that I sometimes have a different order like this:

[Links url="my_url" external="other_value" label="my_label"]

My previous preg_match_all doesn't work with this. I have tried to put each pattern between (...) or use | but I don't get the expected result. I have seen solutions here to identify strings but I need more than identifying strings, I need to extract values.

It's probably something trivial for a regex expert.

Thanks

Solution

If the properties could also be a different amount in any order and should start with [Links , you can make use of the \G anchor. The key is in capture group 1, the value in capture group 2.

(?:\[Links|\G(?!^))(?=[^][]*])\h+([^\s=]+)="([^\s"]+)"

Explanation

(?: Non capture group
- \[Links Match [Links
- | Or
- \G(?!^) Assert the position at the end of the previous match, not at the start
) Close non capture group
(?=[^][]*]) Positive lookahead, assert a ] at the right
\h+ Match 1+ horizontal whitespace chars
( Capture group 1
- [^\s=]+ Match 1+ times any char except = or a whitespace char
) Close group 1
=" Match literally
( Capture group 2
- [^\s"]+ Match 1+ times any char except " or a whitespace char
)" Close group 2 and match "

Regex demo

Example

$re = '/(?:\[Links|\G(?!^))(?=[^][]*])\h+([^\s=]+)="([^\s"]+)"/m';
$str = '[Links label="my_label" url="my_url" external="other_value"]';

preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
print_r($matches);

Output

Array
(
    [0] => Array
        (
            [0] => [Links label="my_label"
            [1] => label
            [2] => my_label
        )

    [1] => Array
        (
            [0] =>  url="my_url"
            [1] => url
            [2] => my_url
        )

    [2] => Array
        (
            [0] =>  external="other_value"
            [1] => external
            [2] => other_value
        )

)

Php demo