meta_key & meta_value not working with get_pages and custom taxonomy

Question

I'm trying to use custom taxonomy with pages. Basically a page has a "relevance" taxonomy, depicting who the page is relevant for. The pages are created in a hierarchy based on the departmental structure of the school district which the site is for. So say I'm on the alumni page, and I want to list all the child pages of educational services that are relevant, like how to get your transcripts.

I've tried the following two methods

<?php 
  $pages = get_pages( array( 'child_of' => '65','hierarchical' => 0, 'meta_key' => 'relevance', 'meta_value' => 'alumni' ) );
  foreach ( $pages as $page ) {
    echo $page->post_title;
  }
 ?>

and

<?php wp_list_pages( array( 'child_of' => '65', 'meta_key' => 'relevance', 'meta_value' => 'alumni') ); ?>

both display the child pages of 65 without the meta_key & meta_value properties, but once I had them I get nothing. I'm super positive the values are correct.

I've also tried..

'relevance' => 'alumni',

like you would in a query, but that doesn't work with these functions.

Any idea why this wouldn't work? The get_pages function lists meta_key & meta_value under usage and denotes that you have to set hierarchical to 0 which I did.

Answer 1

Custom taxonomies are not meta values, but rather their own thing. I don't think wp_list_pages() or get_pages() can query based on a taxonomy, so I'd recommend using WP_Query instead:

<?php
$relevant_pages_args = array(
    'post_type' => 'page',
    'posts_per_page' => -1,
    'post_parent' => 65,
    'tax_query' => array(
        array(
            'taxonomy' => 'relevance',
            'field' => 'slug',
            'terms' => 'alumni'
        )
    )
);

$relevant_pages = new WP_Query( $relevant_pages_args );

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

    <a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>

<?php endwhile; endif; wp_reset_postdata(); ?>