Module development and code questions

In FillPDF, class FillPdfFormField extends ContentEntityBase. The method ::baseFieldDefinitions() uses BaseFieldDefinition::create() to create a bunch of fields. I need to write an update hook to change one of these from type string to string_long.

I am trying to figure out why something weird is happening. I have the following in my_module.routing.yml:

my_module.test:
  path: '/my-module/test'
  defaults:
    _controller: '\Drupal\my_module\Controller\TestController::view'
    _title_callback: '\Drupal\my_module\Controller\TestController::getTitle'
  requirements:
    _permission: 'access content'

My Controller class is this:

Hey, there!

Is it always necessary to do a dependency injection for a service within a class if we will only use that service once inside the class? According to the Drupal documentation, is that recommended, but for practical purposes, is that useful?

 I have custom table having thousands of rows. I want to send the emails to the users by fetching the data from rows at specific time.
i am using Cron job but issue is this ---- timeout issue occurs. As fetching the thousands of rows and manipulate the data takes too much time. Can any one help me ? is there any way to use queue with cron.
thanks ..
 

Playing around with forms and ajax but ran into problems. When I add a form element before the ones that should be added dynamically it's stops working if the element is required.  I thought I could solve it by skipping required and validate instead but it gave the same result (and I do like to have the red star :-).

I'm to much of a rookie in Drupal 8/9 to have any clue on how to solve this so I really hope there is someone with a solution.

Im running Drupal 8.9.0.

Hello,

 Possibility to move an element of a form before another element thanks to the module create personally.

 Cordially.