Yii2 Display Error Messages Inside Modal - php

Question

Here's how I implement my modal in my index.php view:
<?= Html::button(
'Change Password',
['value' => Url::to(['changepassword']). '&id=' . $session['user_id'],
'class' => 'btn btn-success',
'id' => 'modButton'
]) ?>
<?= Yii::$app->session->getFlash('message'); ?>
<?php
Modal::begin(['id' => 'modal2']);
echo "<div id='modContent'></div>";
Modal::end();
?>
And here is my modal form:
<?php $form = ActiveForm::begin(); ?>
<?= Yii::$app->session->getFlash('message'); ?>
</br>
<?= $form->field($model, 'password')->passwordInput(['value' => '', 'style' => 'width: 300px;'])->label('New Password') ?>
<?= $form->field($model, 'ConfirmNewPassword')->passwordInput(['value' => '', 'style' => 'width: 300px;']) ?>
<div class="form-group">
<?= Html::submitButton($model->isNewRecord ? 'Create' : 'Change Password', ['class' => $model->isNewRecord ? 'btn btn-success' : 'btn btn-primary']) ?>
</div>
<?php ActiveForm::end(); ?>
In my controller (just in case you'll be needing it):
if ($model->load(Yii::$app->request->post())) {
$model->password = sha1($model->password);
if($model->password !== sha1($model->ConfirmNewPassword)){
Yii::$app->session->setFlash('message', "Passwords don't match!");
return $this->redirect(['index']);
}
}
Every time I input an invalid password in my modal, the page redirects to the modal form in a separate page and there it displays the error message. I want that when the user inputs an invalid password, the modals stays with the error message somewhere inside it.
How do I do this?

Answer 1

Yes because you redirect to the "index" action if the password is not the same in Controller :
if($model->password !== sha1($model->ConfirmNewPassword)){
Yii::$app->session->setFlash('message', "Passwords don't match!");
return $this->redirect(['index']);
}
Should becomes :
if($model->password !== sha1($model->ConfirmNewPassword)){
Yii::$app->session->setFlash('message', "Passwords don't match!");
}
else {
return $this->redirect(['index']);
}