Drupal 8.x

I want to implement a multistep form using ajax, the first step is a welcome screen with only text and submit button, when the user press start (submit) it increase the step and move to the next step, the next step have different form elements and a submit button.

the form is working correctly, I need to make the form replace in the new step using ajax and without reloading the whole page.

the following code is demonstrating my current form class without ajax and it's working as expected:

I have following structure: 

--Parent link (#)

---Child1(/parentlink/child1)

---Child2(/parentlink/child2)

When I click on parent link I want that menu is expanded so I put # as link path. Show as expanded is checked for parent link. Also in menu block Expand all menu items is checked. This worked previously but somehow stopped. I honestly don't have any idea how to fix this so would appreciate any idea. Thanks.

Hi guys,

Last days spending alot of time creating a website in drupal 8. I used a premade theme from DrupalExp: https://www.drupalexp.com/themes/nation

Now my website is almost done just wanted to integrate some security measures starting with updating to the most recent version.

Sometimes, finding the right module in Drupal is difficult because of a lack in knowing the right term.

So.... I hope someone knows this.

I'd like to create a (long) page with a series of layers of a fixed height - let's say, a series of five layers that are 300px high each - , and when you click a button at the bottom of each layer, it folds out. My designer has come up with this idea and I think it can be done in Drupal, but I don't know what module I should use for this.

Your help is appreciated!

I have update my site to latest  version (Drupal 8.7.1). But according to Patchman on my server, it still complains about a security issue:

Input Validation vulnerability in Drupal
/home/injuryclaims/public_html/core/modules/serialization/src/Normalizer/NormalizerBase.php

Should this be ignored?