Group posts by values from a custom field - Right posts number by values but same post title

Question

I would like to groupe WP post (from 'dlm_download' post type by values from an acf field 'telechargement_type_fichier'.

Value 1 : Post 1 Post 2 Post 3

Value 2 : Post 4 Post 5 Post 6

Value 3 : Post 7 Post 8 Post 9 ...

Here's my code :

$field_posts = array();
$args = array(  
    'post_type' => 'dlm_download',
    'post_status' => 'publish',
);

$query = new WP_Query($args);

while ( $query->have_posts() ) {
        $query->the_post();
        $field = get_post_meta(get_the_ID(), 'telechargement_type_fichier',true);
        $field_posts[$field][] = $post;
    }

  
 wp_reset_query();

foreach ($field_posts as $field_post => $field_title) {

    echo '<p style="font-weight:bold;">' . esc_html($field_post) . '</p>';

    foreach ($field_title as $post_listing => $listing) 
    {   setup_postdata($listing);
        $id = get_the_id();
        $title = get_the_title($id);
        var_dump($title);
    }
wp_reset_postdata();
}

However, here's the result I obtain :

Value 1 - programme_scolaire

Post 1 - Title
Post 1 - Title
Post 1 - Title

Value 2 - module

Post 1 - Title

Value 3 - flyer

Post 1 - Title
Post 1 - Title

Value 4 - jeu

Post 1 - Title
Post 1 - Title
Post 1 - Title
Post 1 - Title

I obtain the real posts number by existing values field but same post/title into the loop. May be post id error or "reset_postdata()"... Don't understand why.

Could you help me ?

Thanks !

Answer 1

I found the solution.

Making an array :

$field_posts = array();

Making a query with posts you would like to filter by field value and calling the ACF field and value you want to display.

$args = array(  
    'post_type' => 'dlm_download',
    'post_status' => 'publish',
    'posts_per_page' => 20,
        );
$query = new WP_Query($args);

while ( $query->have_posts() ) {
        $query->the_post();
        $title = get_the_title();
        $value = get_field_object('telechargement_type_fichier');
        $field = $value['value']['label'];
        $field_posts[$field][$title] = $post;
   }

Making a foreach loop into a foreach loop to classify each post per field value

foreach($field_posts as $field_post => $field_title) {

    echo '<p><strong>' . $field_post . '</strong></h3>';

    foreach($field_title as $post_listing => $listing) {
        echo '<p>' . $post_listing . '</p>';
    }

} wp_reset_postdata();

I obtain :

• Field value 1

  Post 1
  Post 2

• Field value 2

  Post 3
  Post 4

etc .........

Answer 2

I'm not super familiar with PHP/Wordpress, but I think your inner foreach should look like this:

foreach ($field_post as $post_listing) 
{   setup_postdata($post_listing);
    $id = get_the_id();
    $title = get_the_title($id);
    var_dump($title);
}

Or

foreach ($field_post as $post_listing => $listing) 
{   
    var_dump($listing);
}