Module should load on the (any) page edit in the backend

[Leftfield]

I created this as a hook and it's working great, so I decided to turn it into a module to share. We have option in the backend to calculate number of characters but this script is calculating the width of the text as it should be displayed in Google's SERP for the meta title and meta description. However, it's not working for some reason (that I can't identify).

This (primitive) module should load on the (any) page edit in the backend. As you can see, it's supposed to load two files. I'm not sure why it's not functioning.

// Module: SeoTextWidth.module

class SeoTextWidth extends WireData implements Module {

  public static function getModuleInfo() {
    return [
      'title' => 'SEO field Text Width module',
      'summary' => 'This module is calculating width of text in the fields named seo and desc.',
      'version' => 1
    ];
  }

  public function __construct() {
    parent::__construct();
  }

  public function init() {
    $this->addHookAfter('ProcessPageEdit::render', [$this, 'addResources']);
  }

  public function addResources(HookArgs $args) {
    $output = $args->getOutput();
    $page = $args->wire('page');

    // Check if we're on the page edit view for a valid page
    if ($page && $page->editable()) {

      $jsUrl = $this->config->urls->scripts . 'SeoTextWidth.js';
      $output->append("<script src='$jsUrl'></script>");

      $cssUrl = $this->config->urls->styles . 'SeoTextWidth.css';
      $output->prepend("<link rel='stylesheet' href='$cssUrl' />");
    }

    return $output;
  }
}

 

Edited May 1 by Leftfield
I am sorry. Mods, please move this post in the Module/Plugin Development

[Leftfield]

Resolved.

 

  public function init() {
    $this->addHookAfter('ProcessPageEdit::buildForm', $this, 'addResources');
  }

  public function addResources(HookEvent $event) {
	  $page = $event->object;   
	
	  $this->config->styles->add($this->config->urls->SeoTextWidth . "SeoTextWidth.css");
	  $this->config->scripts->add($this->config->urls->SeoTextWidth . "SeoTextWidth.js");
      
	  }