append PHP function to the_content

Question

I'm using the Jetpack plugin for related items and social sharing. Both of these options filter the_content and append themselves to the end of it. The problem is that I'm using custom navigation in my posts which I output by using this code above and after the_content in my single.php.

<div class="navigare">  
    <?php multipagebar(); ?>
    <div class="dropdown">
        <?php TA_content_jump(1); ?> 
    </div>
</div>  

I know that to append something to the_content I can use a filter:

add_filter('the_content', function($content)
{
    return 'text-to-append' . $content;
});

My question and problem is: how to append the navigation PHP functions so that they display before the related and social sharing items of Jetpack?

Answer 1

You will need to experiment with priority.

add_filter(
  'the_content', 
  function($content) {
      return 'text-to-append' . $content;
  },
  10 // this is a priority number; 10 is default
);

The "10" is the default priority. I don't know what number JetPack uses but your original code, without a priority, should run at "10" so I'd try "9", or "8". It should be possible to get your code to execute before JetPack's code.