Custom Search for CPTs and Taxonomies in WordPress

The default WordPress search looks at posts and pages, but real-world sites often need a dedicated search across custom post types (CPTs) with filters by custom taxonomies and even custom fields. This guide shows two robust approaches: (A) enhance the native search using pre_get_posts, and (B) build a dedicated, fully controlled search page using WP_Query. You’ll get copy-paste snippets for the form, query logic, and results.

Approach A: Extend the Native Search (pre_get_posts)

Use WordPress’s built-in search URL (?s=keyword) and add extra params like post_type[]=book or genre[]=12. This is the quickest way to support CPTs and tax filters on /?s=….

1) Search Form (supports multiple CPTs & taxonomy terms)

<form role="search" method="get" action="<?= esc_url( home_url( '/' ) ); ?>">
  <label>
    <span class="screen-reader-text">Search</span>
    <input type="search" name="s" value="<?= esc_attr( get_search_query() ); ?>" placeholder="Keywords…" />
  </label>

  <!-- CPT checkboxes: search across books + courses -->
  <fieldset>
    <legend>Content Types</legend>
    <label><input type="checkbox" name="post_type[]" value="book"   <?php checked( in_array( 'book',   (array) ($_GET['post_type'] ?? []), true ) ); ?>> Books</label>
    <label><input type="checkbox" name="post_type[]" value="course" <?php checked( in_array( 'course', (array) ($_GET['post_type'] ?? []), true ) ); ?>> Courses</label>
  </fieldset>

  <!-- Custom taxonomy: genre (multi-select) -->
  <fieldset>
    <legend>Genres</legend>
    <?php
    $terms = get_terms( [
      'taxonomy'   => 'genre',
      'hide_empty' => false,
    ] );
    $selected = array_map( 'intval', (array) ($_GET['genre'] ?? []) );
    foreach ( $terms as $t ) :
    ?>
      <label>
        <input type="checkbox" name="genre[]" value="<?= (int) $t->term_id; ?>" <?php checked( in_array( $t->term_id, $selected, true ) ); ?>>
        <?= esc_html( $t->name ); ?>
      </label>
    <?php endforeach; ?>
  </fieldset>

  <button type="submit">Search</button>
</form>

2) Modify the main query with pre_get_posts

<?php
// functions.php
add_action( 'pre_get_posts', function( $q ) {
  if ( ! $q->is_main_query() || ! $q->is_search() || is_admin() ) return;

  // 2.1 Post types (allow list)
  $allowed_cpts = [ 'post', 'page', 'book', 'course' ]; // adjust to your site
  $pt = array_values( array_intersect(
    $allowed_cpts,
    array_map( 'sanitize_key', (array) ($_GET['post_type'] ?? []) )
  ) );
  if ( empty( $pt ) ) {
    // default to CPTs you want searchable
    $pt = [ 'book', 'course' ];
  }
  $q->set( 'post_type', $pt );

  // 2.2 Taxonomy filters (genre)
  $genre_ids = array_filter( array_map( 'intval', (array) ($_GET['genre'] ?? []) ) );
  if ( $genre_ids ) {
    $tax_query = (array) $q->get( 'tax_query' );
    $tax_query[] = [
      'taxonomy' => 'genre',
      'field'    => 'term_id',
      'terms'    => $genre_ids,
      'operator' => 'IN',   // OR within the same taxonomy by default
    ];
    $q->set( 'tax_query', $tax_query );
  }

  // 2.3 Sort newest first
  $q->set( 'orderby', 'date' );
  $q->set( 'order', 'DESC' );
} );

Notes: The example uses “IN” (OR logic within one taxonomy). If you add multiple taxonomy arrays, set $tax_query['relation'] = 'AND' when you need to require all tax filters at once.

Approach B: Dedicated Search Page (full control with WP_Query)

For advanced scenarios (compound AND/OR logic, meta ranges, custom sorting), build a standalone template (e.g., a page “/find/”) that runs its own WP_Query. This avoids side effects on the native search and keeps the logic isolated and testable.

1) Create the page template

<?php
/* Template Name: CPT Finder */
get_header();
?>

<h1>Find Content</h1>

<!-- Reuse the form from Approach A (action can point to this page's permalink) -->

<?php
// Collect inputs safely
$keyword   = isset($_GET['s']) ? wp_unslash( $_GET['s'] ) : '';
$posttypes = array_values( array_intersect(
  ['book','course'], array_map( 'sanitize_key', (array) ($_GET['post_type'] ?? []) )
) );
if ( empty( $posttypes ) ) $posttypes = ['book','course'];

$genres = array_filter( array_map( 'intval', (array) ($_GET['genre'] ?? []) ) );

// Build tax_query with AND across different taxonomies (example)
$tax_query = [];
if ( $genres ) {
  $tax_query[] = [
    'taxonomy' => 'genre',
    'field'    => 'term_id',
    'terms'    => $genres,
    'operator' => 'IN', // OR within genre
  ];
}
if ( count( $tax_query ) > 1 ) {
  $tax_query = array_merge( ['relation' => 'AND'], $tax_query );
}

// Optional: meta range filter (e.g., difficulty or price)
$meta_query = [];
if ( isset($_GET['level']) && in_array( $_GET['level'], ['beginner','intermediate','advanced'], true ) ) {
  $meta_query[] = [
    'key'   => 'difficulty',
    'value' => sanitize_text_field($_GET['level']),
    'compare' => '=',
  ];
}
// Example price range
$min_price = isset($_GET['min_price']) ? (float) $_GET['min_price'] : null;
$max_price = isset($_GET['max_price']) ? (float) $_GET['max_price'] : null;
if ( null !== $min_price || null !== $max_price ) {
  $range = [ 'key' => 'price', 'type' => 'NUMERIC' ];
  if ( null !== $min_price && null !== $max_price ) {
    $range['value']   = [ $min_price, $max_price ];
    $range['compare'] = 'BETWEEN';
  } elseif ( null !== $min_price ) {
    $range['value']   = $min_price;
    $range['compare'] = '>=';
  } else {
    $range['value']   = $max_price;
    $range['compare'] = '<=';
  }
  $meta_query[] = $range;
}
if ( count($meta_query) > 1 ) {
  $meta_query = array_merge( ['relation' => 'AND'], $meta_query );
}

// Pagination
$paged = max( 1, (int) get_query_var('paged') );

// Final query args
$args = [
  'post_type'      => $posttypes,
  's'              => $keyword,
  'tax_query'      => $tax_query ?: [],
  'meta_query'     => $meta_query ?: [],
  'posts_per_page' => 10,
  'paged'          => $paged,
  'orderby'        => 'date',
  'order'          => 'DESC',
  'no_found_rows'  => false, // keep true only if you do NOT need pagination
];

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

<h2>Search Results</h2>

<?php if ( $q->have_posts() ) : while ( $q->have_posts() ) : $q->the_post(); ?>
  <article>
    <h3><a href="<?= esc_url( get_permalink() ); ?>"><?= esc_html( get_the_title() ); ?></a></h3>
    <p><?= esc_html( wp_strip_all_tags( get_the_excerpt() ) ); ?></p>
  </article>
<?php endwhile; ?>

  <?= paginate_links( [
        'total'   => (int) $q->max_num_pages,
        'current' => $paged,
      ] ); ?>

<?php else : ?>
  <p>No results. Try different filters.</p>
<?php endif; wp_reset_postdata(); ?>

<?php get_footer(); ?>

AND vs OR: How to Control Filter Logic

• Within a single taxonomy (e.g., multiple genres): use 'operator' => 'IN' for OR, or 'AND' for must-match all selected terms (rare).
• Across multiple taxonomies (genre + topic): wrap your arrays with ['relation' => 'AND'] to require both taxonomies.
• Meta queries: combine multiple constraints with ['relation' => 'AND'] or 'OR' depending on your use case.

Security & Sanitization Checklist

• Sanitize post_type with sanitize_key() and intersect with an allow list.
• Sanitize term IDs with intval and verify taxonomy names are expected.
• Sanitize text inputs with sanitize_text_field(); URLs with esc_url().
• Escape output in templates: esc_html(), esc_attr(), esc_url().

Performance Tips (big catalogs)

• Indexes: Ensure wp_postmeta has an index on (post_id, meta_key) or use plugins that assist indexing.
• Limit fields: For intermediate merges, use 'fields' => 'ids' to get only IDs.
• Caching: Cache expensive combined ID lists with transients or object cache.
• no_found_rows: Set to true when you don’t need pagination to avoid COUNT queries.

Optional: Show Active Filters Above Results

<p>
  <strong>Keyword:</strong> <?= esc_html( $keyword ?: '—' ); ?><br>
  <strong>Types:</strong> <?= $posttypes ? esc_html( implode( ', ', $posttypes ) ) : '—'; ?><br>
  <strong>Genres:</strong>
  <?php
    if ( $genres ) {
      $names = array_map( fn($id) => get_term( $id, 'genre' )->name ?? '', $genres );
      echo esc_html( implode( ', ', array_filter( $names ) ) );
    } else {
      echo '—';
    }
  ?>
</p>

Conclusion

For simple enhancements, hook into pre_get_posts and feed WordPress extra params for CPTs and taxonomies. When you need strict AND/OR logic, ranges, or custom sorting, create a dedicated finder page with your own WP_Query. With careful sanitization and a lean query plan, you’ll deliver fast, precise search across complex content models.

🎨 Want to learn more? Visit our WordPress Customization Hub for tips and advanced techniques.