How to prepend text to the_content, but after img/shortcode

Question

I was trying to add some text to the beginning of every post (the text comes from post_meta, but for this example let's assume it's static text).

Here's what I tried:

add_filter('the_content', function($content)
{
    return 'Text from meta - ' . $content;
});

However, if the post starts with a - usually floated - image (sometimes even wrapped in a caption shortcode), the added text will come before the image.

I would like for the text to be prepended to the first paragraph in the post. Is there any way to accomplish this without parsing the full HTML?

Answer 1

I finally settled on using a regex, with a limit of 1 so it only happens on the first paragraph:

add_filter('the_content', function($content)
{
    $content = preg_replace('/<p[^>]*>/', '$1Text from meta - ', $content, 1);
    return $content;
});