yii validation 2

UserUpdateForm.php

<?php

namespace app\models;

// proper update unique validation solution:-- https://stackoverflow.com/a/44473290

use Yii;
use yii\base\Model;

class UserUpdateForm extends Model
{
    public $id;
    public $name;
    public $username;
    public $password;
    public $password_confirm;
    public $role;
    public $is_active;

    protected $model;

    /**
     * @inheritdoc
     */
    public function rules()
    {
        return [
            [['name', 'username'], 'required'],
            ['username', 'filter', 'filter' => 'trim'],
            [['is_active'], 'boolean'],
            ['role', 'in', 'range' => Role::getConstantsByName()],
            [['name', 'username'], 'string', 'max' => 200],
            [
                'username', 'unique',
                'targetAttribute' => 'username',
                'targetClass' => User::class,
                'targetAttribute' => 'username',
                'filter' => function($query) {
                    $query->andWhere(['not', ['id' => $this->id]]);
                }
            ],
            [['password', 'password_confirm'], 'string', 'min' => 5, 'max' => 255],
            ['password', 'match', 'pattern' => '/[A-Za-z].*[0-9]|[0-9].*[A-Za-z]/', 'message' => 'Password must contain letters and numbers'],
            ['password', 'compare', 'compareAttribute' => 'password_confirm'],
        ];
    }

    /**
     * @inheritdoc
     */
    public function attributeLabels()
    {
        return [
            'id' => 'ID',
            'name' => 'Name',
            'username' => 'Username',
            'password' => 'Password',
            'password_confirm' => 'Confirm Password',
            'is_active' => 'Status',
            'role' => 'Role',
        ];
    }

    public function updateAccount()
    {
        $model = User::findOne(['id' => $this->id]);
        if (is_null($model)) {
            return null;
        }
        if (!$this->validate()) {
            return null;
        }
        $model->name = $this->name;
        $model->username = $this->username;
        $model->is_active = $this->is_active;
        $model->role = $this->role;
        if ($model->getOldAttribute('pass_hash') !== $model->setPassword($this->password)) {
            $model->setPassword($this->password);
        }
        return $model->save() ? $model : false;
    }
}