Modernizing
the FillPDF Drupal module

(By Porting it to Drupal 8)

Created by Kevin Kaland
FillPDF Service

Presentation source: https://github.com/wizonesolutions/modernizing-fillpdf

What was my experience?

(tl;dr: Not as bad as I expected.)

<insert learning curve image with people falling off that @mortendk uses all the time here>

HOWEVER!

"However" what?

D8 isn't actually that scary.
It's the concepts you already know expressed in a different way.
I spent most of my time re-organizing things into the new structure, but I was able to re-use a lot of logic and sometimes even code.
The very same @mortendk was forced to retire as the Angry Themer. He's the Happy Themer now (session).

D8 is more consistent

Patterns are used pretty consistently in core
Your IDE will happily help you understand
You have to define more things, so it's easier to find where things are defined
Some things still feel like magic, but it's magic the wider Modern PHP community expects/understands I think

Verdict:

Learn it!

Now let me save you some time

#learnfrommyfail

The ~~cake~~ documentation page called "Converting modules from 7.x to 8.x" is a lie. Don't bother with it.
Start with Drupal Module Upgrader (DMU) instead! It will tell you a lot of what you need to fix. https://drupal.org/project/drupalmoduleupgrader
There will be other things besides what it says. For that, look at the change records: https://drupal.org/list-changes (filtered by changes introduced in 8.x). These tend to be pretty well-written.
Start with simple things like permissions. Move on to your settings forms if there are any, then move on to more and more complex stuff.
(Coder Upgrade is discontinued, by the way, but regular Coder is still around.)

Biggest fails (stuff that confused me the most):

Database bad, entities good
Many change records show stuff like
```
\Drupal::config('foo.bar')->get('baz')
```
, but you should use dependency injection except in procedural code (which should be rare)
- For example, in form controllers, you can use
```
$this->config->get('foo.bar')->get('baz')
```
- But read the Configuration API docs first :)

King Fail: Dependency Injection

What is this doing?


class HandlePdfController extends ControllerBase {

// ...
public function __construct(FillPdfLinkManipulatorInterface
  $link_manipulator) {
  $this->linkManipulator = $link_manipulator;
}

public static function create(ContainerInterface $container) {
  return new static($container->get('fillpdf.link_manipulator'));
}
// ...

}

King Fail: Dependency Injection

What is this doing?

Side effects of module porting

In summary

Drupal 8 is not that scary
Drupal is competitive again
It's early enough that you can bug the smart people in #drupal-contribute with your questions :)
Backdrop is...okay, but it won't be my choice