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

Answer

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