About chain calls in PHP

Question

I encountered a problem when using PHP chain calls:
There is a class "Site" below:

<?php
class Site{
public function api(){
require('class.Api.php');
$this->api = new Api();
return $this->api;
}
}
?>

There is also a class "Api" located in "class.Api.php":

<?php
class Api{
public function auth(){
//quiet a few
}
public function render(){
//quiet a few
}
}
?>

Use the following code to instantiate:

$site = new Site();

Call the following code again:

$site->api()->auth();
$site->api()->render();

Will PHP repeat require() and create new object API? If so, require() can be replaced by require_once(), but how to make "$site->api()" return the same object? Thanks!

Answer 1

Single case mode.

<?php
class Site{
    
    public function api(){
        if (!isset($this->api)) {
            $this->api = new Api();
        }
        return $this->api;
    }
}
?>

It’s just a simple writing, but it still needs a lot of optimization.

Answer 2

require('class.Api.php');
class Site{
    protected $api;
    
    public function getApi()
    {
        return $this->api;
    }
    
    public function api(){
        $this->api = new Api();
    }
}
?>

$site = new Site();
$site->api();
$site->getApi()->auth();
$site->getApi()->render();