Sticky post appears twice

Question

I am trying to modify the number of posts_per_page in the loop. This way:

function posts_per_page($query) {
    $query->query_vars['posts_per_page'] = 3;
}
add_filter('pre_get_posts', 'posts_per_page', 11);

The problem I have is that when I do so, then sticky posts appear twice in the loop: first one at the begining of the loop and second one in their original position. So in this case, the first page has 4 posts (3 of loop without sticky + the sticky post), and the sticky post will appear (again) later in its "page" with other 2 posts.

EDIT: SOLUTION

After doing quite much research I realised sticky posts appear always in the first page. If the original sticky post was already in the first page then only the sticky appears (this post only will appear one). I needed to know exacty how many posts will my query have, but $wp_query->found_posts was not counting the sticky posts. And if I did $wp_query->found_posts + get_option( 'sticky_posts' ) wouldnt be correct as it doesnt consider the 'sticky post from first page' I said before and also counts non-published sticky posts.

With $wp_query->posts I get the real number of posts in my first page, so:

$sticky = count($wp_query->posts) - get_option( 'posts_per_page' );

if ($sticky<0) {$sticky=0;}//In case there is only one page of results

Now $sticky will have the real number of sticky posts.

Answer 1

What you describe is not an issue but normal WordPress behaviour. When you mark a post as a sticky it will be at the top of the list and it will appear in it's original postition as well, unless the original position is on the first page. A sticky will appear at the top of the posts and in it's original position but it will not appear twice on the same page.

You might want to do something like this:

<?php
while (have_posts()) : the_post();
    if ( !in_array( $post->ID, $do_not_duplicate ) ) { // check IDs         
// display posts ...
        the_title();

//store id in "do not duplicate
$do_not_duplicate = $post->ID;
    }
endwhile;
?>

source with minor edit: http://wpengineer.com/1719/filter-duplicate-posts-in-the-loop/

Answer 2

More correct would be to use the set method.

function posts_per_page($query) {
    $query->set('posts_per_page',3);
}
add_filter('pre_get_posts', 'posts_per_page', 11);

Try that.

Note: I can't duplicate this multiple sticky issue. If that doesn't solve things edit your question with more detail. That may be theme specific or due to a plugin.

Answer 3

Consider a case where one needs the following:

• Keep sticky posts at the top.
• Not duplicate sticky posts in later pages
• Have each page be limited to a specific number of posts (even the first page).

It is very complex to do by setting parameters in the pre_get_posts hook because there is no simple way to set the number of posts for the first page. WordPress naturally sends back all sticky posts + the posts on the first page. It is not a good idea to try to calculate a new value of posts_per_page based on the number of sticky posts of the following complications.

• There are many cases to consider. Sometimes sticky posts are less that the posts_per_page, sometimes more, and sometimes equal. Each case will need to be dealt with separably.
• There is no way to deal with the case where the number of sticky posts exceeds posts_per_page as described in an answer to a similar question

Therefore the solution is to modify the code executes the loop.

                global $wp_query, $post;
                // Setup manual paging scheme.
                $page_requested        = $wp_query->query_vars['paged'] ? $wp_query->query_vars['paged'] : 1;
                $number_per_page       = $wp_query->query_vars['posts_per_page'];
                $first_post_to_display = ( $page_requested - 1 ) * $number_per_page + 1;
                $last_post_to_display  = $first_post_to_display + $number_per_page - 1;
                $current_post          = 1;
                // Re query posts without paging so it won't duplicate the sticky posts.
                $query = new WP_Query( array( 'nopaging' => true ) );
                while ( $query->have_posts() ) :
                    $query->the_post();
                    $should_display_this_post = $current_post >= $first_post_to_display && $current_post <= $last_post_to_display;
                    if ( $should_display_this_post ) {
                        ?>
                  <Template code to output post content here>
 
                <?php } 
                 ++$current_post;
                 endwhile;
?>

Explanation:

• Re query all posts without paging in order to remove duplicates (while preserving the high priority of sticky posts.
• Manually Calculate which posts should be displayed based on the requested page number and the desired posts_per_page.