Pass matched topic wildcards to subscription callback #128

Namoshek · 2022-10-30T20:47:28Z

This PR introduces a new feature for subscriptions made on a wildcard topic. All matched wildcard parts of the topic are now extracted and passed to the subscription callback. This is best explained with an example:

Subscription made on topic pattern 'foo/bar/+'
Message received for topic 'foo/bar/baz'
The matched wildcard topic levels are passed to the subscription callback: ['baz']

Subscription made on topic pattern 'foo/+/bar/#'
Message received for topic 'foo/baz/bar/hello/world'
The matched wildcard topic levels are passed to the subscription callback: ['baz', 'hello/world']

The matched wildcards are passed as fourth parameter to the subscription callback:

$mqtt->subscribe('foo/+/bar/#', function ($topic, $message, $retained, $matchedWildcards) {
    echo sprintf("Received message on topic [%s]: %s\n", $topic, $message);
}, 0);