Craft 3 Controller - Redirect with errors

Question

I cant get this to work.

I'm doing a post to a controller action. From that action I'm doing a lot of validations, db insert, file uploads etc.

Coming from Laravel Im used to is doing like this: (example with no real variables or methods. Just for visual presentation)

if(!$something->success){
  return redirect("controller-url")->withErrors([$model->errors]);
}
// Next steps...

From what I can read in the docs Craft recommend posting to the same page to handle errors and pass the model down to the view, but then doing a page refresh will do the same again so I dont like that.

My Controller is like this :

Index (Renders index template)

public function actionIndex()
{
    $this->renderTemplate("plugin/settings");
}

Post

public function actionPost()
{
  if(!$model->validate()){
    Craft::$app->getSession()->setError($message);
    return $this->redirect("url-to-index-action");
  }
}

So the setError() works fine but I want to the pass all the errors from the model to the index action after a redirect and then down to the twig template. How?

Answer 1

In Yii2 there is no such a thing as "redirectWithErrors". Usually you have 2 scenarios

1. There are validation errors -> display the form again with those errors
2. Successful -> redirect

The first one doesn't require a redirect. You just return null in your controller and Yii2 will route the to the url specified via GETparameter.

So you can have a form like this.

<form method="post" action="myUrl">
    <input type="hidden" name="action" value="mycontroller/save">
</form>

Yii2 will do the following

1. Route to your controller and hit the save action
2. When you redirect or return a valid object of type yii\web\Response or a string that can be converted into that it will return the Response
3. When you don't return something it will route the request a second time with your get param myUrl, that can be treated as you routeWithErrors function because you set the errors Craft::$app->getUrlManager()->setRouteParams(['model' => $model]) and have then access to these parameters.

If you really dislike this, you could use return Craft::runAction('controller/action', $parameters); to run a controller action with certain values

Edit Usually you want to leave action="myUrl" blank and don't insert it. That way Yii2 will automatically reload the current route so you can dispaly your errors