Highlight current post type when inside custom post type

Question

I have a custom post type called: "movie"
I have only 4 movies in my movies section in the site.
Inside each movie post type I want to display all other movies in a side list like so:

• movie 1
• movie 2
• movie 3
• movie 4

so the user can navigate from each movie page to all other movies.

I used this code to display the list of all of my "movie" post types:

<ul>
<?php $loop = new WP_Query( array( 'post_type' => 'movie', 'posts_per_page' => 4, 'order'=>'ASC' ) ); ?>
<?php while ( $loop->have_posts() ) : $loop->the_post(); ?>
    <li>
    <?php the_title( '<a href="' . get_permalink() . '" title="' . the_title_attribute( 'echo=0' ) . '">', '</a>' ); ?>
    </li>
    <?php endwhile; ?>
</ul>

So far it is very simple and working.

I would also like to add a "current" class to each item in the list that corresponds to the post I am currently reading. for instance if I am inside movie 3 I see this:

• movie 1
• movie 2
• movie 3
• movie 4

The problem is that unlike WordPress custom menu, no "current-menu-item" or other class is automatically generated.

any clue how I can accomplish that?

Answer 1

I am assuming that your code is on a "single" post/cpt page.

echo '<ul>';
  $loop = new WP_Query( array( 'post_type' => 'post', 'posts_per_page' => 4, 'order'=>'ASC' ) );
  $obj = get_queried_object();
  $thispage = $obj->ID;
  while ( $loop->have_posts() ) : $loop->the_post(); ?>
    <li><?php 
      if ($thispage === $post->ID) {
        $class = ' class="current-item"';
      } else {
        $class = '';
      }
      the_title( 
        '<a href="' . get_permalink() . '" title="' . the_title_attribute( 'echo=0' ). '"' . $class.' >', 
        '</a>' 
      ); ?>
    </li><?php 
  endwhile;
echo '</ul>';

You want to use get_queried_object to get data about the page you are on and compare the ID to the items in the loop, adding a class attribute if they match. This will not work correctly on archive pages as get_queried_object will not return the same type of data on those pages. Depending on your implementation, you may have to alter the code.