Make constant conditional in php using static method

Question

I'm trying to make IntegratedApp class constant use value from the config file and then use the constant in MakeConnectionController. But the constant PORTAL_BASE_URL_STAG, inside the IntegratedApp class, when assigning a static method to it, an underline error (error message: Constant expression contains invalid operations) appeared on the constant. Is there a way to assign variables to the constant class without using the static method?

Code Example:

config file :

[test]
stagingApiUrl = 'https://api-test-first.com/';

IntegratedApp.php file :

namespace Project\Constants;

class IntegratedApp
{

    const PORTAL_BASE_URL_STAG = self::getUrl();

    public static function getUrl() {
        $base_url = $this->config->test->stagingApiUrl ? $this->config->test->stagingApiUrl : 'https://api-test-second.com/';

        return (string)$base_url;
    }

}

MakeConnectionController.php file:

use Project\Constants\IntegratedApp;


class MakeConnectionController extends BaseController
{
    $baseUrl = IntegratedApp::PORTAL_BASE_URL_STAG;
}

Answer 1

You can do it with this workaround ( use define() ):

<?php
namespace Project\Constants;

define('PORTAL_BASE_URL_STAG',IntegratedApp::getUrl());

class IntegratedApp
{

    const PORTAL_BASE_URL_STAG = PORTAL_BASE_URL_STAG;

    public static function getUrl() {

        return (string)"Foo";
    }

}


print IntegratedApp::PORTAL_BASE_URL_STAG;//Foo

• define() a constant outside of the class in the same file
• use the static method for getting the value
• then use the created constant to set the class constant

Hopfully, you have not so mutch magic going on. And you should fix the $this usage, because in static methods you dont have an access to $this.

Don't ask why this works :-) It works. Seems like there is a kind of late class constant binding going on here.