Wrap iframes/embeds, but do it before oEmbed happens

Question

I am trying to wrap any iframe/embed in my content with some Facebook Instant Articles friendly code (only for that feed). I have it working, but it adds this code to oEmbed output as well which adds in a wrapper that is not needed (since the Facebook Instant Articles already handles oEmbed embeds).

Basically, how can I get the wrap on iframes/embeds to happen before the oEmbed stuff happens?

Below is the code I have:

function wrap_iframe( $content ) {
    if (is_feed( INSTANT_ARTICLES_SLUG )) {
        // Match any iframes or embeds
        $pattern = '~<iframe.*</iframe>|<embed.*</embed>~';
        preg_match_all( $pattern, $content, $matches );
        foreach ( $matches[0] as $match ) {
            $wrappedframe = '<figure class="op-interactive"><iframe>' . $match . '</iframe></figure>';
            $content = str_replace($match, $wrappedframe, $content);
        }
        return $content;
    }
}
add_filter( 'the_content', 'wrap_iframe' );

Answer 1

WordPress embed the URLs on same filter with priority of 8

in /wp-includes/class-wp-embed.php

// Attempts to embed all URLs in a post
add_filter( 'the_content', array( $this, 'autoembed' ), 8 );

and you are parsing content after it with priority of 10 then defiantly you will get the parsed output.

You just need to do it early before WordPress embed URLs

add_filter( 'the_content', 'wrap_iframe', 5 );

Answer 2

There is a specific filter for this: embed_oembed_html.

add_filter('embed_oembed_html', function($html) {
    return '<figure class="op-interactive">'.$html.'</figure>';
}, 11); 

Source: Wordpress codex