Why is my category template ignoring post type?

Question

I am currently working on two sites that make extensive use of custom post types. For both we have a defined number of items (cpts) that fall under a particular bucket (categories).

One of the sites is for a design shop, so the cpts are websites, logos, business cards, etc. And the categories are all the clients (several hundred).

Since the number of categories is quite large and always changing, I need to use a category.php template to display the collected projects (cpts) for a particular client.

I also need my cpts to display in a certain order--so websites in the top section of the page, logos in the bottom section, for example.

I initially created mulitple loops using query_posts & wp_reset_query. This got the posts to show where I wanted, but pagination was screwed up and after reading more I realized using query_posts is a big no-no.

However, whenever I use WP_Query it seems to completely ingnore my post_type argument (and only post_type). For example:

<?php
$current_cat = get_query_var('cat');
$args1 = array(
  'post_type' => 'event',
  'cat' => $current_cat,
  'offset' => 1
);

$query1 = new WP_Query( $args1 );

while ($query1->have_posts()) {
$query1->the_post();
echo '<li><a href="'.get_permalink( $post->ID).'">' . get_the_title() . '</a></li>';
} //endwhile;

?>      

The other thing is that I am only seeing this issue on the category template. When I use a loop similar to the above on a page template it returns the correct post types. What am I missing here?

Answer 1

Your issue is definitely caused by the lack of a pre_get_posts filter. Try this in your theme/functions.php:

// so event cpt is found on assigned cat archive page
function jdk540_event_query_post_type($query) {

    if ( ! is_admin() ) {

        if( is_category() || is_tag() &&  $query->is_main_query() && empty( $query->query_vars['suppress_filters'] ) ) {

            $post_type = get_query_var('post_type');

            if($post_type)
                $post_type = $post_type;
            else
                $post_type = array( 'post', 'event', 'nav_menu_item');

            $query->set('post_type', $post_type);
        }

    }

}
add_action('pre_get_posts', 'jdk540_event_query_post_type');