Repeat Capture Regex

Question

I've been trying to get this Regex to work, and I feel like I almost have it, but I'm not sure how to get the results I desire. I am using a mock data structure that resembles a JSON object, and am trying to parse the parameters.

The structure resembles groups and options like such: group_label:id{option_1:id,option_2:id ... }

The expression I've come up with so far is

(?:(?:(?<group_name>[a-zA-Z0-9 _]+?):(?<group_id>[0-9]+?){(?:(?:(?<option_name>.+?):(?<option_id>.+?))+?,?)+?},?))+?

and the test data I'm using has been:

My Interests:379{Commercial:0,Consumer:1,Wholesale Reseller:2},Test Group:1234{Test One:1,Test 2:2}

Here is a link to the regex tester I'm looking at, you can see that each group turns into a match, but it only captures the last of each option, where I'd like to have a match for all the options as well.

https://regex101.com/r/GkW57Y/1

It also breaks if I try to specify the start and end of the string, so I'm sure that's a hint to me that something I'm doing is wrong, but I'm not a regex expert, and I'm running shorter on time. As always, any advice is always greatly appreciated!

Answer 1

Here's a regex that will extract the groups and options by just looking for the different features (groups end with {, options start with { or , and end with , or }):

(?<group_name>[a-zA-Z0-9 _]+):(?<group_id>[0-9]+)(?={)|(?<=[{,])(?<option_name>[^:]+):(?<option_id>[^,}]+)(?=[,}])

In PHP you can use it like this to get lists of groups and options:

$string = 'My Interests:379{Commercial:0,Consumer:1,Wholesale Reseller:2},Test Group:1234{Test One:1,Test 2:2}';
$regex = '(?<group_name>[a-zA-Z0-9 _]+):(?<group_id>[0-9]+)(?={)|(?<=[{,])(?<option_name>[^:]+):(?<option_id>[^,}]+)(?=[,}])';
preg_match_all("/$regex/", $string, $matches);
//print_r($matches);
$groups = array_combine(array_filter($matches['group_name']), array_filter($matches['group_id'], function ($v) { return $v !== '';}));
$options = array_combine(array_filter($matches['option_name']), array_filter($matches['option_id'], function ($v) { return $v !== '';}));
print_r($groups);
print_r($options);

Output:

Array (
    [My Interests] => 379
    [Test Group] => 1234
)
Array (
    [Commercial] => 0
    [Consumer] => 1
    [Wholesale Reseller] => 2
    [Test One] => 1
    [Test 2] => 2 
)

If you need a more structured output, you can do something like this after getting the matches:

$output = array();
for ($i = 0; $i < count($matches['group_name']); $i++) {
    if ($matches['group_name'][$i] != '') {
        // new group
        $this_group = $matches['group_name'][$i];
        $output[$this_group] = array('id' => $matches['group_id'][$i]);
    }
    else {
        // option for this group
        $output[$this_group]['options'][$matches['option_name'][$i]] = $matches['option_id'][$i];
    }
}
print_r($output);

Output:

Array (
    [My Interests] => Array (
        [id] => 379
        [options] => Array (
            [Commercial] => 0
            [Consumer] => 1
            [Wholesale Reseller] => 2
        )
    )
    [Test Group] => Array (
        [id] => 1234
        [options] => Array (
            [Test One] => 1
            [Test 2] => 2
         )
    ) 
)

Or possibly this might be more useful:

$output = array();
$this_group = -1;
for ($i = 0; $i < count($matches['group_name']); $i++) {
    if ($matches['group_name'][$i] != '') {
        // new group
        $this_group++;
        $output[$this_group] = array('name' => $matches['group_name'][$i], 'id' => $matches['group_id'][$i]);
    }
    else {
        // option for this group
        $output[$this_group]['options'][$matches['option_name'][$i]] = $matches['option_id'][$i];
    }
}
print_r($output);

Output:

Array (
    [0] => Array (
        [name] => My Interests
        [id] => 379
        [options] => Array (
            [Commercial] => 0
            [Consumer] => 1
            [Wholesale Reseller] => 2
        )
    )
    [1] => Array (
        [name] => Test Group
        [id] => 1234
        [options] => Array (
            [Test One] => 1
            [Test 2] => 2
         )
    ) 
)

Demo on 3v4l.org