Html_Links_PHP_Guard.md

Try the code

<?php

class AuthGuard
{

	public static function guard()
	{
		return false;
	}
	
}

class TrialGuard
{

	public static function guard()
	{
		return true;
	}
	
}

class Link
{
	
  	protected $guards = [];
	protected $html;

 	public function __construct( $url, $text, $attrs = '' )
   	{
   	    $attrs = $attrs == '' ? $attrs : " " . $attrs;
   		$this->html = "<a href=\"$url\"" . $attrs . ">$text</a>";
   	}

   	public function guard( array $guards = [])
   	{
   		$this->guards = $guards;
   		return $this;
   	}

   	function __toString()
   	{
        
   		foreach ( $this->guards as $guard )
   		{
   			if( !$guard::guard() )
   			{
   				return ''; // or throw an exception
   			}
   		}

   		return $this->html;
   	}
 	      
}

$link1 = new Link( 'https://google.com', 'Google' );
echo $link1->guard([
    TrialGuard::class
]);

$link2 = new Link( 'https://yahoo.com', 'Yahoo', 'class="btn" style="color:#000000;"' );
echo $link2->guard([
    TrialGuard::class
]);

$link3 = new Link( 'https://hotmail.com', 'Hotmail' );
echo $link3->guard([
    TrialGuard::class, AuthGuard::class
]);