Shortcode: How to add custom posts?

Question

I am having problems with post__in shortcode atts. It does not show anything. I think the problem is that post__in must be an array but the shortcode ID returns string.

function courses_shortcode($atts) {

 extract(shortcode_atts( array(
    'limit' => 16,
    'id' => array(592, 862, 418, 491, 1227, 1015, 847, 738, 541, 1186, 664, 695, 785),

), $atts ));


  $q_courses = new WP_Query( array(
    'post_type' => array('course'),
    'posts_per_page'  => $limit,
    'post__in' => $id,
    'orderby'    => 'post__in',

));
add_shortcode('video-course', 'courses_shortcode');

The problem is that if I do [video-course limit=8 id="418, 1186"] does not show anything. Limit is working but the ID is not.

Answer 1

Correct. post__in requires an array but the id parameter in [video-course limit=8 id="418, 1186"] is passed in as a string, so in your shortcode, you would have to parse it into an array in order to use it:

if ( !is_array($id) ) {
    // If $id is not an array (not your default value in your example) 
    // then simultaneously parse it into an array and trim white space:
    $id = array_map('trim', explode(',', $id));
}

Then you can use:

'post__in' => $id