blurkness Before I address your questions, why do you want to add your own wrapper on YouTube videos? You can already style them in CSS:
[data-s9e-mediaembed="youtube"] { border: 1px solid #000; }
I don't know why your modification doesn't work but I guess it's possible it is executed before the s9e/mediaembed extension is, which would overwrite it. What you should do is this: look into the event system to make sure yours is executed after the media embed tags are created. And don't use add()
to get the tag, use $configurator->tags['youtube']
.
About Reddit threads, it depends on the version of the library currently installed. The latest released Flarum is limited to 0.4.11 and Reddit threads were added in a 0.5.x version.