edlp_d8/sites/all/themes/custom/edlptheme/edlptheme.theme

<?php

/**
 * @file
 * Functions to support theming in the edlp theme.
 */


use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Template\Attribute;

// function edlptheme_preprocess_input(&$vars){
  // dsm($vars, 'vars');
  // $vars['attributes']['placeholder'] = "salut";
// }

function edlptheme_preprocess_node(&$vars){
  $node = $vars['elements']['#node'];
  $options = ['absolute' => TRUE];
  $url = \Drupal\Core\Url::fromRoute('entity.node.canonical', ['node' => $node->id()], $options);
  $system_path = $url->getInternalPath();
  $vars['link_attributes'] = new Attribute(array(
    'data-drupal-link-system-path' => $system_path=='' ? '<front>' : $system_path
  ));
}

/**
 * Implements hook_form_alter
 */
function edlptheme_form_user_login_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  // dpm($form_id, 'form_id');
  // dpm($form, 'form');
  $form['name']['#attributes']['placeholder'] = (string) $form['name']['#title'];
  unset($form['name']['#title']);
  $form['pass']['#attributes']['placeholder'] = (string) $form['pass']['#title'];
  unset($form['pass']['#title']);
}

function edlptheme_preprocess_edlp_productions(&$vars){
  foreach($vars['nodes'] as &$node){
    switch($node['vm']){
      case "image_2_columns":
        $cols = 4;
        break;
      case "image_1_columns":
        $cols = 2;
        break;
      case "text_1_column":
        $cols = 2;
        break;
    };
    $node['cols'] = $cols;
  }
  // dpm($vars);
}