[Theme: Underscores (_S) – custom build] PHP Error in my functions.php

I tried putting the hook code outside and correctly it worked.
I don’t know what to do about the loop though, it still gives me this error:

Parse error: syntax error, unexpected T_ENDWHILE in /Users/lucasdechow/Sites/the-damn-margin-blog/wp-content/themes/tdm/functions.php on line 188

Hmm perhaps I use the endwhile wrongly…

I fixed it using this code instead.

Just if anyone finds this thread and wonders how it is done this is how to do it:

First we make a function (in functions.php) called featured which will create a custom WP_Query.

function featured(){
	$featured = new WP_Query( 'posts_per_page=1' );
		if ( $featured->have_posts() ) { 

		while ( $featured->have_posts() ) : $featured->the_post();

			get_template_part( 'content', get_post_format() );

		endwhile;
		}
}
add_action('tdm_before_header','featured');

Now I have created a hook using this function:

function tdm_before_header() {
    do_action('tdm_before_header');
}

…and calls it from the theme using the function itself (note: excerpt) :

...
<div id="page" class="hfeed site cf">
	<?php tdm_before_header(); ?>
	<header id="masthead" class="site-header" role="banner">
...