Một số kiến thức code Drupal 8 khá hay cần biết qua

Drupal 8 Cheat Sheet

<?php

// Messenger - (D7 drupal_set_message)
 \Drupal::messenger()->addMessage(t('Show this message to the user.'));

// Message Types
 \Drupal::messenger()->addMessage($message, 'status');
 \Drupal::messenger()->addMessage($message, 'warning');
 \Drupal::messenger()->addMessage($message, 'error');

// Another way of displaying error type messages.
\Drupal::messenger()->addError(t('The user account %id does not exist.', ['%id' => $uid]));

// Add messenger to your class for use with $this->messenger
  /**
   * Gets the messenger.
   *
   * @return \Drupal\Core\Messenger\MessengerInterface
   *   The messenger.
   */
  public function messenger() {
    if (!isset($this->messenger)) {
      $this->messenger = \Drupal::messenger();
    }
    return $this->messenger;
  }

// **** working with nodes ******

 // Check if an entity is a node.
 if ($entity instanceof \Drupal\node\NodeInterface) {
    $node = $entity;
 }
 // or
 if ($entity->getEntityTypeId() == 'node') {
    $node = $entity;
 }
 
// check the bundle type of a node
$node_type = $entity->getType();

  // Load by ID
  $node = Node::load($nid);

   
   //Load mathod 2 - https://www.metaltoad.com/blog/drupal-8-entity-api-cheat-sheet
  $node_storage = \Drupal::entityTypeManager()->getStorage('node');
  $node = $node_storage->load($nid);

  // Get a node from a form
  $node = $form_state->getFormObject()->getEntity();
  $is_new = $node->isNew();

  // Get node id.
  $nid = $node->id();

  // Get node title
  $title = $product->getTitle();    // use this
  $title = $product->title->value;  // although this is the same (but should use the function)

  // Get a field value array
  $node->get('field_name')->getValue();
  $node->field_name->getValue();

  // Get the 2nd value of a multi value field
  $node->field_name->getValue()[1]['value'];
  // Get the 3nd reference ID of a multi value entity reference field
  $node->field_name->getValue()[2]['target_id'];
  // Count the number of values
  count($node->field_name->getValue())

  // Get a field value
  $node->field_name->Value;

 // Single node entity reference field
  $nid = $node->get('field_contact')->first()->getValue()['target_id'];
  $node = Node::load($nid);

  // Cycle a Entity reference fields
  foreach ($node->field_po_lines as $reference) {
    $entity_id = $reference->target_id;
    $entity_storage = \Drupal::entityTypeManager()->getStorage('minirigs_po_line');
    $entity = $entity_storage->load($entity_id);
  }

  // Cycle a Entity reference fields (th long way)
  foreach ($node->field_po_lines as $po_line) {

    /** @var \Drupal\Core\Entity\Plugin\DataType\EntityReference $entityReference */
    $entityReference = $po_line->get('entity');

    /** @var \Drupal\Core\Entity\Plugin\DataType\EntityAdapter $entityAdapter */
    $entityAdapter = $entityReference->getTarget();

    /** @var \Drupal\Core\Entity\EntityInterface $referencedEntity */
    $referencedEntity = $entityAdapter->getValue();
  }

// Get all the referenced entities in one go
 $all__referenced_entities =  $node->get('field_po_lines')->referencedEntities();

// Create node - need to include:
use Drupal\node\Entity\Node;

// Create a node mathod 1a - simple
 $node = Node::create(['type' => 'article', 'title' => 'Sample article API', 'path' => ['alias' => '/sample-article-api']]);
 $node->save();

// Create a node mathod 1b - more details
    $data = [
      'uid'      => $user->id(),
      'name'     => 'admin',
      'type'     => 'article',
      'langcode' => LanguageInterface::LANGCODE_NOT_SPECIFIED,
      'title'    => $this->randomMachineName(),
      'body' => 'body text',
      'multivalue_field' => [ ['value' => 'first'], ['value' => 'second'] ]
      'status' => 1,
      'created' => '1435019805',
    ];
    $node = Node::create($data);
    $node->save();

    // Create a node mathod 2 - field by field
    $node = Node::create(['type' => 'article']);
    $node->set('title', 'Title');
    $node->set('field_text', 'My text');
    $node->save();

  // Populate a multivalue field for a string holding comma delimited values
  $value = '1,2,3,4';
  $value_array = explode(',', $value);
  foreach ($value as $key => $value) {
    $value_array[$key] = ['value' => trim($value)];
  }
  $node->set('multivalue_field', $value_array;

drupal_8_services.php

<?php

  // Get the request object.
  $request = \Drupal::request();
  // Query - get all parameter. 
  $q = $request->query->all();
  // Check if a query parameter exists.
  if ($request->query->has('commerce_product_v_id')) {
    // Get the query parameter.
    $pvid = $request->query->get('commerce_product_v_id');
  }



// Drupal messenger (from commerce_stock)
\Drupal::messenger()->addMessage(t('Updated the stock.')); 
\Drupal::messenger()->addError(t('The maximum quantity for %name that can be ordered is %qty.', [
          '%name' => $name,
          '%qty' => $stock_level,
        ]));
      }

Drupal_8_commerce_code_cs.php

<?php
// Work with orders.
    /** @var \Drupal\commerce_order\Entity\OrderInterface $order */
    $order = \Drupal::entityTypeManager()->getStorage('commerce_order')->load($order_id);

$order_id = $order->id();

// Work with line items.
    $qty = $order_item->getQuantity();


// Work with products
    // Load the product variation.
    $variation_storage = \Drupal::service('entity_type.manager')->getStorage('commerce_product_variation');
    $product_variation = $variation_storage->load($variation_id);
    $variation_id = $product_variation->id();

// Get the product form the variation
      $product = $product_variation->getProduct();
      $product_id = $product_variation->getProductId();



 // Cycle the line items of an order and load each product.
 foreach ($order->getItems() as $id => $order_item) {
    $purchased_entity = $order_item->getPurchasedEntity();
    $pe_price = $purchased_entity->getPrice();
    if (!$purchased_entity) {
      // Not every order item has a purchased entity.
      continue;
    }
    $name = $purchased_entity->getTitle();
    $qty = $order_item->getQuantity();
    //  Unit price
    $unit_price_obj = $order_item->getUnitPrice(); 
    $price_amount = $unit_price_obj->getNumber();
    $price_currency = $unit_price_obj->getCurrencyCode();
    // Line total price
    $line_price_obj = $order_item->getTotalPrice(); 
 }

// Stock
    // Check if a product is available.
    $availabilityManager = \Drupal::service('commerce.availability_manager');
    $availabe = $availabilityManager->check($product_variation, $prod_qty);

  // Create a stock transaction
    $stockManager = \Drupal::service('commerce_stock.service_manager');
    // High level typed transaction using the stock manager. 
    $stockManager->receiveStock($purchasable_entity, $location_id, $zone, $quantity, $unit_cost, $message);
    // Low level un-typed transaction using the stock updater.
    $stockManager->getService($purchasable_entity)->getStockUpdater()->createTransaction($purchasable_entity, $location_id, $zone, $quantity, $unit_cost, $transaction_type, $metadata);


 // Get Stock level
    // Get the Stock service for the PurchasableEntity and use that to get the stock checker.
    $stock_service = $stockManager->getService($entity);
    $stock_checker = $stock_service->getStockChecker();
    // You can then check if it is always in stock:
    stock_checker->getIsAlwaysInStock($entity)
    // Get the configuration object. Needed to get the locations to check for.
    // $stock_config = $stock_service->getConfiguration();
    // and finally you can get the stock level:
    $stock_level = $stock_checker->getTotalStockLevel(
        $entity,
        $stock_config->getAvailabilityLocations($context, $entity)
    );


    // Needs the following use at the top of the file:
    // use Drupal\commerce_product\Entity\ProductVariationInterface;
    // Check if a purchasable entity is a product variation.
     if ($purchasable_entity instanceof ProductVariationInterface) {
       // Get the product variation from a line item.
       $product_variation = $line_item->getPurchasedEntity();
     }
    
    // Get the Cart provider service
    $cart_provider = \Drupal::service('commerce_cart.cart_provider');

    // Get all the carts.
    $all_carts = \Drupal::service('commerce_cart.cart_provider')->getCarts();

    // Get the current store.
    $store = \Drupal::service('commerce_store.current_store')->getStore();
    
    // Get the cart for the curent store.
    $cart = \Drupal::service('commerce_cart.cart_provider')->getCart('default', $store);


    // get the store from an order
   $order->getStore();
   $order->getStoreid();


// Add to cart form
    // Get the add to cart entity form.
    $entity_form = $form_state->getFormObject();
    // Get the line item and $purchased_entity.
    $order_item = $entity_form->getEntity();
    /** @var \Drupal\commerce\PurchasableEntityInterface $purchased_entity */
    $purchased_entity = $order_item->getPurchasedEntity();

// Get the $context from the Add to cart form     
    /** @var \Drupal\commerce_product\Entity\ProductInterface $product */
    $product = $form_state->get('product');
    $selected_variation_id = $form_state->get('selected_variation');
    if (!empty($selected_variation_id)) {
      $selected_variation = \Drupal\commerce_product\Entity\ProductVariation::load($selected_variation_id);
    }
    else {
      $selected_variation = $product->getDefaultVariation();
    }
    $context = commerce_stock_enforcement_get_context($selected_variation);
         
// Working with the cart page
    // Get the order from the form state.
    $order = $form_state->getFormObject()->getEntity();

// Checkout
  // Check if the checkout form. need to make sure its not the commerce_checkout_flow_form (used to create new checkout flows)
  if (strpos($form_id, "commerce_checkout_flow") !== false && $form_state->getFormObject()->getBaseFormId() == 'commerce_checkout_flow') {
    // Get the order from the form
    /** @var Drupal\Core\Form\FormInterface $form_object */
    $form_object = $form_state->getFormObject();
    /** @var \Drupal\commerce_order\Entity\OrderInterface $order */
    $order = $form_object->getOrder();
      
      
// get a field value using getValue(), check it and cycle using the store. 
$store = $context->getStore();      
$locations = $store->field_available_stock_locations->getValue();
// If we have store locations.
if (!empty($locations)) {
      // Load them.
      $store_locations = [];
      foreach ($locations as $location) {
        $store_locations[$location['target_id']] = $location['target_id'];
      }
      $store_locations = $this->loadMultiple($store_locations);
}
      
  // Check what type is a PurchasableEntity.      
  $entity_type = $entity->getEntityTypeId();   //example: commerce_product_variation
  $entity_bundle = $entity->bundle();   //example: default
      
// Reading a field with a single value - all the below will return the same value
  $external_product_id = $entity->field_external_product_id->getValue()[0]['value'];
  $external_product_id = $entity->field_external_product_id->getString();
  $external_product_id = $entity->field_external_product_id->value;
  $external_product_id = $entity->field_external_product_id[0]->value;
      
// User data
    
    // Get details from the order  
    $billing_profile = $order->getBillingProfile();
    $email =  $this->order->getEmail();
    $address = $billing_profile->address->first();
    $line_1 = $address->address_line1,
    $line_2 = $address->address_line2,
    $city = $address->locality,
    $company = $address->organization,
    $country = $address->country_code,  
    $first_name = $address->given_name,
    $middle_name = $address->additional_name,
    $last_name = $address->family_name,
    $state = $address->administrative_area,
    $post_code = $address->postal_code,
      
    // Get address as an array
   $billing_profile->get('address')->first()->toArray())      
      

// Shipping
    // Get the shipments entity from the order reference. 
    $shipments = $order->shipments->referencedEntities();
    $shipments = $order->get('shipments')->referencedEntities();
    // Get the first shipment entity.
    /** @var \Drupal\commerce_shipping\Entity\ShipmentInterface $shipment */
    $shipment = reset($shipments);
    // Get shipping Profile
    $shipping_profile = $shipment->getShippingProfile();
    // Get the address (from this point its the same as billing address)  
    $address = $shipping_profile->address->first();
    $line_1 $shipping_profile->get('address')->address_line1;
      
    // Get the address book profile ID.
    $address_book_profile_id = $shipping_profile->getData('address_book_profile_id');
    $address_book_profile = Profile::load($address_book_profile_id);
    $is_default = $address_book_profile->isDefault();
      
      
    // Shipping Method info.
    $shipping_method = $shipment->getShippingMethod();

    $shipping_method_label = $shipment->getShippingMethod()->label();
    $shipping_method_id = $shipment->getShippingMethodId();

    // Shipping service info.
    $shipping_service = $shipment->getShippingService();

    // Amount.
    $shipping_amount_obj = $shipment->getAmount();
    $shipping_original_amount_obj = $shipment->getOriginalAmount();
    $shipping_amount = $shipping_amount_obj->getNumber();
    $shipping_amount_currency =$shipping_amount_obj->getCurrencyCode()

    // Other
    $package_type = $shipment->getPackageType();
    $package_type = $shipment->getPackageType();
    $package_type_id = $shipment->getPackageType()->getId();
      
      
   
 // Payment
  // Payment method.
    $payment_method = $order->get('payment_method')->entity;
    // Payment method values.
    $method_id = $payment_method->get('method_id')->value;
    $payment_type = $payment_method->get('type')->value;
    $card_type = $payment_method->get('card_type')->value;
    // The remote ID returned by the request.
    $remote_id = $payment_method->get('remote_id')->value;
  // Payment Gateway  
    $payment_gateway = $payment_method->get('payment_gateway')->referencedEntities()[0];
    $payment_gateway_mode = $payment_method->get('payment_gateway_mode')->value;
    $payment_gateway_id = $payment_gateway->get('id');
    $payment_gateway_configuration = $payment_gateway->get('configuration');
    // Payment Gateway API Key
    $api_key = $payment_gateway_configuration['api_key'];      
              
      
       
      
 // Price adjustments
       
// full documentation: https://docs.drupalcommerce.org/commerce2/developer-guide/pricing/adjustments       
       
/** @var \Drupal\commerce_order\Entity\OrderItemInterface $order_item */
$adjustment_amount = $order_item->getUnitPrice()->multiply(0.1);
$order_item->addAdjustment(new Adjustment([
  'type' => 'custom',
  'label' => 'Plus 10%',
  'amount' => $adjustment_amount,
  'percentage' => '0.1',
  'included' => FALSE,
  'locked' => TRUE,
]));
      
$order_item->addAdjustment(new Adjustment([
    'type' => 'fee',
    'label' => '$10 fee',
    'amount' => new Price('10.00', 'USD'),
]);

// Read pricing information.
  $order_item->getUnitPrice();
  $order_item->getTotalPrice();
  $order_item->getAdjustedTotalPrice();
  $order_item->getAdjustedTotalPrice(['custom']);
  $order_item->getAdjustedTotalPrice(['fee']);  
                         
// Order adjustments
$order->addAdjustment(new Adjustment([
  'type' => 'fee',
  'label' => 'Handling fee',
  'amount' => new Price('10.00', 'USD'),
  'locked' => TRUE,
]));
// Read pricing information.
$order->getTotalPrice();
$order->getSubtotalPrice();    
$order->getAdjustments();
$order->getAdjustments(['fee'])      
                           
// Split a $10 discount across all the lines of an order. 
$splitter = \Drupal::getContainer()->get('commerce_order.price_splitter');
/** @var \Drupal\commerce_order\Entity\OrderInterface $order */
$amounts = $splitter->split($order, new Price('10.00', 'USD'));
foreach ($order->getItems() as $order_item) {
  if (isset($amounts[$order_item->id()])) {
    $order_item->addAdjustment(new Adjustment([
      'type' => 'custom',
      'label' => $this->t('Special'),
      'amount' => $amounts[$order_item->id()]->multiply('-1'),
    ]));
  }
}       
                           
// Calculate the total unit discount for a line:
$purchased_entity = $order_item->getPurchasedEntity();
$purchased_entity_price = $purchased_entity->getPrice()->getNumber();
$line_adjustmented_unit_price = $order_item->getAdjustedUnitPrice()->getNumber();
$unit_discounbt = $purchased_entity_price - $line_adjustmented_unit_price;                         

Products get remaining time

function _kf_products_get_remaining_time($expiry_date) {
    $remaining = '';
    $diff = $expiry_date - REQUEST_TIME;
    $days = floor($diff / 86400);
    $hours = floor(($diff - ($days * 86400)) / 3600);
    $minutes = floor(($diff - ($days * 86400) - ($hours * 3600)) / 60);
    $seconds = floor($diff - ($days * 86400) - ($hours * 3600) - ($minutes * 60));
    if ($diff > 86400) {
      $remaining .= $days . ' d ';
    }
    if ($hours > 0) {
      $remaining .= $hours . ' h ';
    }
    if ($minutes > 0) {
      $remaining .= $minutes . ' m ';
    }
    if ($diff < 86400) {
      $remaining .= $seconds . ' s ';
    }
    return $remaining;
  }