In the functions.php:
add_action('wp_enqueue_scripts', function() {
wp_enqueue_script('autocomplete-search', get_stylesheet_directory_uri() . '/assets/js/autocomplete.js',
['jquery', 'jquery-ui-autocomplete'], null, true);
wp_localize_script('autocomplete-search', 'AutocompleteSearch', [
'ajax_url' => admin_url('admin-ajax.php'),
'ajax_nonce' => wp_create_nonce('autocompleteSearchNonce')
]);
$wp_scripts = wp_scripts();
wp_enqueue_style('jquery-ui-css',
'//ajax.googleapis.com/ajax/libs/jqueryui/' . $wp_scripts->registered['jquery-ui-autocomplete']->ver . '/themes/smoothness/jquery-ui.css',
false, null, false
);
});
add_action('wp_ajax_nopriv_autocompleteSearch', 'awp_autocomplete_search');
add_action('wp_ajax_autocompleteSearch', 'awp_autocomplete_search');
function awp_autocomplete_search() {
check_ajax_referer('autocompleteSearchNonce', 'security');
$search_term = $_REQUEST['term'];
if (!isset($_REQUEST['term'])) {
echo json_encode([]);
}
$suggestions = [];
$query = new WP_Query([
's' => $search_term,
'posts_per_page' => -1,
]);
if ($query->have_posts()) {
while ($query->have_posts()) {
$query->the_post();
$suggestions[] = [
'id' => get_the_ID(),
'label' => get_the_title(),
'link' => get_the_permalink()
];
}
wp_reset_postdata();
}
echo json_encode($suggestions);
wp_die();
}
Create the autocomplete.js:
jQuery(function($) {
$('.search-form .search-field').autocomplete({
source: function(request, response) {
$.ajax({
dataType: 'json',
url: AutocompleteSearch.ajax_url,
data: {
term: request.term,
action: 'autocompleteSearch',
security: AutocompleteSearch.ajax_nonce,
},
success: function(data) {
response(data);
}
});
},
select: function(event, ui) {
window.location.href = ui.item.link;
},
});
});