I will share how I achieved to implement what I consider to be an advanced custom search using WordPress out-of-the-box functionalities and ACF, without custom PHP scripts that are questionable.
- Creating a custom post type
- Adding a custom field to the custom post type
- Creating the search form
- Outputting the search results
Custom Post Type:
For the first step it is relatively easy, create your own custom post type, within your functions.php file or somewhere else:
Resources:
https://www.codexworld.com/wordpress-custom-post-types-without-plugin/
function product_init() {
$labels = array(
'name' => 'Products',
'singular_name' => 'Product',
'add_new' => 'Add New Product',
'add_new_item' => 'Add New Product',
'edit_item' => 'Edit Product',
'new_item' => 'New Product',
'all_items' => 'All Products',
'view_item' => 'View Product',
'search_items' => 'Search Products',
'not_found' => 'No Products Found',
'not_found_in_trash' => 'No Products found in Trash',
'parent_item_colon' => '',
'menu_name' => 'Products',
);
$args = array(
'labels' => $labels,
'public' => true,
'has_archive' => true,
'show_ui' => true,
'capability_type' => 'post',
'hierarchical' => false,
'rewrite' => array('slug' => 'product'),
'query_var' => true,
'menu_icon' => 'dashicons-randomize',
'supports' => array(
'title',
'editor',
'excerpt',
'trackbacks',
'custom-fields',
'comments',
'revisions',
'thumbnail',
'author',
'page-attributes'
)
);
register_post_type( 'product', $args );
register_taxonomy('product_category', 'product', array('hierarchical' => true, 'label' => 'Category', 'query_var' => true, 'rewrite' => array( 'slug' => 'product-category' )));
}
add_action( 'init', 'product_init' );
Custom fields:
Creating a custom field without ACF was more complicated than I expected, use Advanced Custom Fields plugin instead, and create a custom field applied to 'Type of Content' > 'Product' – or either custom post type you have. Create the fields such as: ‘City’, etc.
Search form:
Create a file called searchform.php within your template’s folder, and it will contain a simple <form>:
<form id="searchform" method="get" action="<?php echo esc_url( home_url( "https://wordpress.stackexchange.com/" ) ); ?>">
<input type="text" class="search-field" name="s" placeholder="Search" value="<?php echo get_search_query(); ?>">
<input type="hidden" name="post_type[]" value="product" />
<input type="submit" value="Search">
</form>
Resources:
https://wordpress.stackexchange.com/a/17119/219065
https://artisansweb.net/create-custom-search-form-wordpress/
Results:
Within the search.php file, I go the following code:
$args = array(
'post_type' => 'product',
'meta_query' => array(
array( 'key' => 'city', 'value' => 'Moscow', 'meta_compare' => 'LIKE' ),
array( 'key' => 'city', 'value' => array('Edinburgh', 'Moscow'), 'meta_compare' => 'IN' ),
'relation' => 'OR'
)
);
$the_query = new WP_Query( $args );
if ( $the_query->have_posts() ) {
while ( $the_query->have_posts() ) : $the_query->the_post();
echo get_the_title();
endwhile;
} else {
echo "No posts";
}
wp_reset_postdata();
Resources:
https://www.smashingmagazine.com/2016/03/advanced-wordpress-search-with-wp_query/
https://rudrastyh.com/wordpress/meta_query.html
Meta_query compare operator explanation
postscript. You will have to tweak and adapt a big portion of the code because it is of course not ready to handle all situations where you are going to be using the search function. And I found many elements in the code unnecessary and incomplete (check the resources for more), but it serves just as an example and I hope it helps you.