Managing product and SKU display

Displaying content¶

You can use the following methods to display your content:

• Pre-process functions

  The reference SKU entity can be accessed using the first value from field_sku. The SKU field has an override for the get method and when it is called with ‘entity’ will return the referenced entity. Once you have access to the referenced SKU entity you can then call entity view builders to render the entity or specific fields. You cannot access the SKU entity directly in Twig from field_skus so we assign the SKU object directly to a property on the variables render array.

  $product = $variables['node'];
  /** @var \Drupal\acq_sku\Entity\SKU $sku */
  $sku = $product->get('field_skus')->first()->get('entity')->getValue();
  $variables['final_price'] = $sku->get('final_price')->getValue();
  $variables['sku'] = $sku;
  $viewBuilder = \Drupal::entityTypeManager()->getViewBuilder('acq_sku');
  $field = $sku->get('attr_color'); $build['color'] = $viewBuilder->viewField($field);
  

• Twig templates

  Twig requires that the template file be preprocessed to provide it complete access over the referenced entity. This will need to be assigned to a render variable as previously described.

  {{ sku.final_price.value }}
  {{ sku.attr_my_custom_attribute.value }}
  

Price fields¶

The following price fields are stored in the SKU entity:

• Price (was price): The initial price of the product

• Special price (now price): The updated price

• Final price: The now price with all discounts from catalog rules

  applied

Media fields and files¶

The SKU contains raw data in the Media field. You can process the field’s data by using a custom module to load the images as a Drupal image, and then display them on product pages. To do this, complete the following steps:

1. Create a node pre-process function. Using a hook_preprocess_node function, you can create an image element for the product node render array.

2. Load the SKU. The SKU is stored as a string in a multi-value field, but only the first value will be used. The SKU:loadFromSku()method can be used to load the SKU entity.

3. Load the media information. The SKU entity has a getMedia()method that will process the raw media information, create a file entity if needed with the downloaded image, and then return an array of media information. Each element of this array has a file key with a file entity.

4. Create a render array element. With the file entity, you can create a render array element. #theme with value image_style is a way to do this. You will provide a #style_name that refers to an image style configured for the website and the image URI which can be obtained with the file entity getFileUri() method.

5. Configure output with Twig templates. You can then handle the new element in node template files. For example, you can access a $build['image'] variable in the preprocess function as {{ elements.image }} in a twig template.

6. Create and modify different view modes. The pre-process function will include a variable for $view_mode and you can use this to format the image differently depending on the node view mode. For example, include a thumbnail on a teaser of the product.

Refer to the following code for an example of adding media:

<?php

use Drupal\acq_sku\Entity\SKU;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
use Drupal\file\Entity\File;

/**
 * Demonstrate adding images to product pages.
 */
function acq_example_node_view(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display, $view_mode) {
  if ($entity->bundle() == 'acq_product') {
    // The first SKU entry is the only one used at this time.
    $sku_id = $entity->get('field_skus')->first()->getString();
    $sku = SKU::loadFromSku($sku_id);

    // Add the first SKUs first image to the render array.
    if ($sku instanceof SKU) {
      $build['image'] = [];

      // Process the media information and create file entity as needed.
      $sku_media = $sku->getMedia();

      /**
     * There may be multiple images. We are getting just the first here.
       *
       * @var File $sku_image_file
       */
      if (isset($sku_media[1]['file'])) {
        $sku_image_file = $sku_media[1]['file'];
      }

      /**
       * Create a render array.
       *
       * The image will be available as {{ elements.image }} in templates.
       */
      $build['image'] = [
        '#theme' => 'image_style',
        '#style_name' => 'large',
        '#uri' => $sku_image_file->getFileUri(),
      ];
    }
  }
}