Static methods with __construct

Question

I need to use static methods with __construct() method to instantiate the Client object but the as far as I know there is no way to use the __construct() since the object is not instantiated when using static methods.

I thought I can use an init method.

class API
{

    static $client;

    public static function init()
    {
        $settings = [
            'username' => 'user1',
        ];

        self::$client = new Client($settings);
    } 

    public static function foo( )
    {
        self::$client->action('Foo text');
    }

}

API::init();

Then I can load the above class in other places and do the below.

API::foo();

My Questions:

1. Is there anything wrong with the way I wrote the class?
2. Does the above codes cause performance issue?
3. Is there any better way?

Any help is appreciated.

Answer 1

As an approach this method is fine, but to be more SOLID here I would pass Client in init() function like init(Client $client) rather than instantiating it right in class. So do and $settings , better pass as an argument or preserve in some private variable rather than hardcoding in initializer.

It refers to D and L letter, the Dependency Inversion Principle and Liskov Substitution Principle

No performance issues, but only an architectural approach. But as to me I don't see any preconditions here for avoiding constructor and use $api = new API($client, $settings); rather than static invocation.

And constructor ( or initializer ) signature would look like

public function __construct(Client $client, array $settings);