OOP_MVC_CMS.php

<?php
class Rules {
  // Sets all of the rules to check a given field
  public $ruleParameters = ['isRequired', 'maxLenght', 'minLength', 'atLeastOne'];
  // Creates all of the specific parameters for the rules
  public function __construct($parameters){
    foreach($parameters as $parameter => $value) $this->ruleParameters[$parameter] = $value;
  }
  // Checks if a string follows all of the parameters
  public function checkRules($string) {
    $strLength = strlen($string);
    if($this->ruleParameters['isRequired'] && !($strLength !== 0)) return false;
    if($this->ruleParameters['maxLenght'] < $strLength || $this->ruleParameters['minLength'] > $strLength) return false;
    if(!preg_match("/[" . $this->ruleParameters['atLeastOne'] . "]/" , $string, $matches)) return false;
    // if it passes through it all, returns true
    return true;
  }
}
      
class Validator extends Rules {
  // Calls the parent constructor method with the parameters passed in
  public function __construct($params) {
    parent::__construct($params);
  }

  // Checks if a given password follows a set of rules
  public function checkPassword($password) {
    return $this->checkRules($password);
  }
}
      
// Creates a new instance of the validator class, with all of the parameters
$validator = new Validator([
  "isRequired" => true, 
  "maxLenght" => 20,
  "minLength" => 6,
  "atLeastOne" => " !\"#$%&'()*\+,-.\/:;<=>?@\[\]^_`{|}~",
]);
// If the validator method returns false, exits the program after refreshing the page and setting a session variable
if(!$validator->checkPassword($password)) {
  header("Refresh:0");
  $_SESSION['password'] = 'wrong';
  exit;
}
?>  
<div class="form-floating">
  <input name="password" type="password" class="form-control" id="floatingPassword" placeholder="Password">
  <label for="floatingPassword">Password</label>
  <?php if(isset($_SESSION['password']) && $_SESSION['password'] == 'wrong') {
    echo "<p style='color: #ee5a5a'>Password must contain 6 to 20 characteres and also a special char!</p>";
    // After echoing the error message resets the Session variable
    unset($_SESSION['password']);
  }

 ?>
</div>
      
      
      

About youtube, that's a shame, it's pretty frustating, hope they'll fix it