How to use dotenv variables into a class? - php

Question

I just start learning PHP few days ago so forgive me if this question is a newbie one.
What is wrong with my declaration of CRAWLER_URI ? The env() isn't working outside a method and I don't know why.
namespace App\Http\Controllers;
use GuzzleHttp\Client;
class SpotifyController extends Controller
{
const CRAWLER_URI = env('CRAWLER_URI') . ':' . env('CRAWLER_PORT');
/**
* Send a GET to Crawler API
* #return a json crawled by an external API crawler
*/
public function fetch()
{
$client = new Client(['base_uri' => self::CRAWLER_URI]);
$response = $client->request('GET');
dd($response);
}
}

Answer 1

So, the issue here is that you can’t use a function as a class constant value:
According to the PHP manual:
The value must be a constant expression, not (for example) a variable, a property, or a function call.
There are many solutions to this problem, for example, if you really want it to be constant, you could use a define() statement like this:
define('CRAWLER_URI', env('CRAWLER_URI') . ':' . env('CRAWLER_PORT'));
and access it like this:
echo CRAWLER_URI;
Another method would be to use a static function:
private static function CRAWLER_URI() {
return env('CRAWLER_URI') . ':' . env('CRAWLER_PORT');
}
and access it like this:
echo $this->CRAWLER_URI();