WordPress auto-complete post search by title with typeahead-bootstrap

functions.php

function theme_styles()
{
    wp_enqueue_style( 'boostrap_css', 'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css' );
    wp_enqueue_style( 'theme_css', get_template_directory_uri() . '/css/theme.css' );
}
add_action( 'wp_enqueue_scripts', 'theme_styles' );

function theme_js()
{

    wp_enqueue_script(  'bootstrap_js', 'https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js', array('jquery'), '', true );
    //Download from here - https://github.com/bassjobsen/Bootstrap-3-Typeahead
    wp_enqueue_script(  'typehead__boostrap_js', get_template_directory_uri() . '/js/typeahead-bootstrap.js', array('jquery'), '', true );
    wp_enqueue_script(  'theme_js', get_template_directory_uri() . '/js/theme.js', array('jquery', 'jquery-ui-datepicker'), '', true );
    wp_localize_script( 'theme_js', 'theme_data', array('site_url' => network_site_url( '/' )) );

}
add_action( 'wp_enqueue_scripts', 'theme_js' );

include( get_template_directory() . '/api/process-get-companies.php' );

//Endpoint for getting companies
function water_endpoints()
{
    register_rest_route('companies/v1', '/companies/', array(
        'methods' => 'GET',
        'callback' => 'get_companies'
    ));
}
add_action( 'rest_api_init', 'water_endpoints' );

post-type-page.php

//I will leave the rest for you.

<input class="typeahead form-control" type="text" placeholder="Search..." data-provide="typeahead">

process-get-companies.php

<?php
//NOTE - function.php expects it to be inside an api folder. 

//I'm returning the post title inside of a link. Do it however you wish and adjust accordingly
//in the typeahead.js file
function get_companies(WP_REST_Request $request)
{
    $companies = query_posts( array(
        "post_type" => "company",
        "s"         => $request['q']
    ) );

    $companies_names = [];

    foreach( $companies as $company )
    {
        $permalink    = get_post_permalink($company->ID);
        $name         = "<a class='company-link' href=$permalink>$company->post_title</a>";
        array_push($companies_names, $name);
    }

    return $companies_names;


}



?>

typeahead.js

(function($) {

$('.typeahead').typeahead({
    //So we can render HTML inside the list
    highlighter: function(item) {
          return item;
    },
    updater: function (item) {
        //redirect user on click
        window.location.href = $(item).attr("href");
    },
    source: function (query, process) {
        return $.get(theme_data.site_url + 'wp-json/companies/v1/companies', { q: query }, function (data) {
            return process(data);
        });
    }
});

})(jQuery);