Query a custom taxonomy for certain posts

Question

I am trying to show some posts on a template based on their custom taxonomy.

Here is my template code:

<?php $field = get_field('newsletter_date'); ?>
                <?php 
                $args = array (
                'orderby'                => 'rand',
                'taxonomy' => 'newsdates',
                'field' => 'id',
                'terms' => "$field",
                'post_type' => 'post',
                );

                $queryarticles = new WP_Query( $args ); ?>

                <?php while ($queryarticles -> have_posts()) : $queryarticles -> the_post(); ?>

                <h4 class="homerssfeed"><a href="<?php the_permalink() ?>" class="nound"><?php the_title(); ?></a></h4>

                <span class="dcecright">
                    <?php the_content(); ?>

                </span>
                <?php endwhile;?>
                <?php wp_reset_postdata(); ?>

and here is what is in my function.php:

// Register Custom Taxonomy
function newsdates_taxonomy()  {

    $labels = array(
        'name'                       => _x( 'Newsletter Dates', 'Taxonomy General Name', 'text_domain' ),
        'singular_name'              => _x( 'Newsletter Date', 'Taxonomy Singular Name', 'text_domain' ),
        'menu_name'                  => __( 'Newsletter Date', 'text_domain' ),
        'all_items'                  => __( 'All Newsletter Dates', 'text_domain' ),
        'parent_item'                => __( 'Parent Date', 'text_domain' ),
        'parent_item_colon'          => __( 'Parent Date:', 'text_domain' ),
        'new_item_name'              => __( 'New Date', 'text_domain' ),
        'add_new_item'               => __( 'Add Newsletter Date', 'text_domain' ),
        'edit_item'                  => __( 'Edit Date', 'text_domain' ),
        'update_item'                => __( 'Update Date', 'text_domain' ),
        'separate_items_with_commas' => __( 'Separate dates with commas', 'text_domain' ),
        'search_items'               => __( 'Search dates', 'text_domain' ),
        'add_or_remove_items'        => __( 'Add or remove dates', 'text_domain' ),
        'choose_from_most_used'      => __( 'Choose from the most used dates', 'text_domain' ),
    );
    $args = array(
        'labels'                     => $labels,
        'hierarchical'               => false,
        'public'                     => true,
        'show_ui'                    => true,
        'show_admin_column'          => true,
        'show_in_nav_menus'          => true,
        'show_tagcloud'              => true,
    );
    register_taxonomy( 'newsdates', 'post', $args );

}

// Hook into the 'init' action
add_action( 'init', 'newsdates_taxonomy', 0 );

}

Answer 1

You are setting your taxonomy arguments incorrectly in WP_Query. You need to set up a tax_query, which takes an array of arrays. See the codex.

$args = array(
    'post_type' => 'post',
        'orderby' => 'rand',
    'tax_query' => array(
        array(
            'taxonomy' => 'newsdates',
            'field' => 'id',
            'terms' => $field
        )
    )
);