Can't add text in front of shortcode

Question

Currently I'm using this shortcode within a post

http://pastebin.com/K7WC2Lk3

which works great, but somehow I can't add any text in front of this shortcode, without posting it the other way around.

In example

some dummy text [etalage]

will always be shown as

[etalage] some dummy text

I've read to gather the value into a variable and return it, but I have to admit, I'm not entirely sure how to accomplish this best

Answer 1

Here's your updated shortcode function which puts output in a variable and returns it. Note that you have to use functions that return data rather than output directly, in this case get_the_post_thumbnail() is used in place of the_post_thumbnail()

function cor_etalage_add_shortcode() {
    $output = '<div id="etalage"><ul>';

    $the_query = new WP_Query(array(
        'post_type' => array(
            'portfolio'
        )
    ));

    while ($the_query->have_posts()) : $the_query->the_post();
        $output .= '<li>'. get_the_post_thumbnail($post->ID,'etalage') .'</li>';
    endwhile;
    wp_reset_postdata();
    $output .= '</ul></div>';

    return $output;
}
add_shortcode('etalage', 'cor_etalage_add_shortcode');

EDIT oops, forgot to pass the post ID with get_the_post_thumbnail, updated.