Calling wordpress post by custom taxonomy

Question

I defined a custom taxonomy in WordPress as below:

function content_selector() {
  register_taxonomy(
      'contentselector',
      'post',
      array(
              'label' => __( 'Content Selector' ),
              'rewrite' => array( 'slug' => 'cs' ),
              'hierarchical' => true,
      )
  );
}
add_action( 'init' , 'content_selector' );

It shows up in new posts and values can be assigned, actually it seems working. But when I use following function for calling posts by this taxonomy, there is no success.

add_shortcode('rps', 'rpsf');
function rpsf() {
     $args =[ 'posts_per_page' => 1, array(

             'tax_query' => array(
                            array(
                                 'taxonomy' => 'contentselector',
                                 'field' => 'slug',
                                 'terms' => 'one-of-the-assigned-terms')
          ))];

  $query = new WP_Query( $args );

     if ( $query->have_posts() ) : while ( $query->have_posts() ) : $query->the_post();
          ob_start();  ?>

              <div class="rpst">
              <a href="<?php the_permalink(); ?>"><span><?php the_title(); ?></span</a>
              </div>

      <?php endwhile; endif; wp_reset_postdata();
   return ob_get_clean();
}

Did I make a mistake in defining taxonomy or in calling posts?

Answer 1

It is easier to debug your code if you properly format it, as well as staying consistent regarding the notation you use (for example, [] vs array()).

After 'cleaning' up your $args definition, it's clear to see that it is incorrectly structured:

$args = array(
    'posts_per_page' => 1,
    array(
        'tax_query' => array(
            array(
                'taxonomy' => 'contentselector',
                'field' => 'slug',
                'terms' => 'one-of-the-assigned-terms'
            )
        )
    )
);

It should look more like this:

$args = array(
    'posts_per_page' => 1,
    'tax_query' => array(
        array(
            'taxonomy' => 'contentselector',
            'field' => 'slug',
            'terms' => 'one-of-the-assigned-terms'
        )
    )
);