Module development and code questions

Hello,

I'm working with Drupal 8.7.4.

I made a view form in a modal and it works fine, the fields to chose appear in the modal and i can submit the research from it.

So now, i wish to display the results in the same modal. Currently, the results appear in an entire new page and actually i don't know how to do for having the results in the initial modal.

Here is the code of the initial modal:

Hi,

I am trying to open a modal dialogue using the code that is given in the documentation. But the modal dialog is not opening. Please let me know what is going wrong in my code. I appreciate your help.

<?php
/**
* Implementation of hook_form_alter
*/
use Drupal\Core\Ajax\AjaxResponse;
use Drupal\Core\Ajax\OpenModalDialogCommand;
use Drupal\Core\Ajax\ReplaceCommand;
use Symfony\Component\DependencyInjection\ContainerInterface;

I'll start out by apologizing, I realize this isn't directly Drupal related, but it is "general" enough I'm hoping someone will be kind and help me. I'm not asking for a "how-to", just basically help me identify this piece of code, and point me in the right direction. 

I'm working on my first "Headless Drupal" project, using Gatsby. I needed to do something, did a Google search, and found what appears to be a solution; however, in the documentation it has code snippets which are labeled "DIFF". (Here's an example)

Hello Friends,

The Problem: Create a function that will continually check the date_created field of entries in my database. If the date_created is older than 6 hours, I would like to perform a particular action. The problem is that I need this function always be checking for database entries older than 6 hours without me having to do anything (view website or push a button etc). In other words I need that function to always be running in the background of my website, without it having to be triggered by anything.

Hi,

I am trying to find out the routing name of a taxonomy word. I am trying to create a link inside my form that takes me to the Add term page of the taxonomy. For this purpose I need to know the relevant routing name. How can I do that?

Thanks

Hello,