Issue #1328388 by rfay: Add a more extensive line item type with callbacks

line_item_example/line_item_example.install

@@ -13,4 +13,17 @@
 function line_item_example_enable() {
   // This function configures all existing line item types, including ours.
   commerce_line_item_configure_line_item_types();
+}
+
+/**
+ * Implements hook_uninstall().
+ */
+function line_item_example_uninstall() {
+  $variables = array(
+    'line_item_example_line_item_2_amount',
+    'line_item_example_line_item_2_currency',
+  );
+  foreach ($variables as $variable) {
+    variable_del($variable);
+  }
 }
\ No newline at end of file

line_item_example/line_item_example.module

@@ -2,6 +2,7 @@
 /**
  * @file line_item_example.module
  * Demonstrates the addition of a new pane to the checkout system.
+ *
  */
 
 /**
@@ -32,24 +33,213 @@ function line_item_example_info_page() {
 /**
  * Implements hook_commerce_line_item_type_info().
  *
+ * - example_line_item_1 is simply a clone of the 'product' line item type. It's
+ *   a simple way to get a differentiated line item type.
+ * - example_line_item_2 is completely implemented and is not a product line
+ *   item type but rather a "surcharge", and the hook_commerce_order_presave()
+ *   is provided to make sure that there is one for every order.
+ *
  * @see hook_commerce_line_item_type_info().
  * @see http://www.drupalcommerce.org/specification/info-hooks/checkout
  *
  */
 function line_item_example_commerce_line_item_type_info() {
 
-  $line_item_types['example_line_item'] = array(
-    'name' => t('Example Line Item'),
-    'description' => t('Example Line Item type of line item'),
+  $line_item_types['example_line_item_1'] = array(
+    'name' => t('Example Line Item 1'),
+    'description' => t('Simplest Example Line Item Type'),
     'product' => TRUE,
 
-    // Here you can change the text in the submit button in the add to cart form
+    // Here you can change the text in the submit button in the order admin form.
     'add_form_submit_value' => t('Add product'),
+
+    // 'base' basically provides magic naming for a set of callbacks
+    // including the settings_form, checkout_form, etc. Here we'll use the
+    // forms and callbacks provided for Commerce Product Reference module for
+    // its product line item, so we'll use
+    // commerce_product_line_item_configuration()
+    // and commerce_product_line_item_title(), etc.
+    // See example_line_item_2 for explicit callbacks.
     'base' => 'commerce_product_line_item',
   );
+  $line_item_types['example_line_item_2'] = array(
+    'name' => t('Example Line Item 2'),
+    'description' => t('A more complex line item type, providing explicit callbacks'),
+    'product' => FALSE,
+
+    // Here you can change the text in the submit button in the order admin
+    // line item add area.
+    'add_form_submit_value' => t('Add surcharge'),
+
+    // We could use 'base' to configure the forms we need but instead we'll
+    // name the callbacks explicitly.
+
+    // 'base' => 'line_item_example_example_2',
+
+    'callbacks' => array(
+      'configuration' => 'line_item_example_example_2_configuration',
+      'title' => 'line_item_example_example_2_title',
+      'add_form' => 'line_item_example_example_2_add_form',
+      'add_form_submit' => 'line_item_example_example_2_add_form_submit',
+    ),
+  );
+
   return $line_item_types;
 }
 
+
+/**
+ * Configure the line item with additional fields or whatever.
+ *
+ * This function is called by the line item module when it is enabled or this
+ * module is enabled. It invokes this function using the configuration_callback
+ * as specified above. Other modules defining product line item types should
+ * use this function to ensure their types have the required fields.
+ *
+ * @param $line_item_type
+ *   The info array of the line item type being configured.
+ *
+ * @see commerce_product_line_item_configuration()
+ */
+function line_item_example_example_2_configuration($line_item_type) {
+  $type = $line_item_type['type'];
+
+  // Here we could add fields or other configuration.
+
+}
+
+/**
+ * Returns a title for this line item.
+ */
+function line_item_example_example_2_title($line_item) {
+  return(t('Line Item Example 2 Order Surcharge'));
+}
+
+/**
+ * Returns the elements necessary to add a product line item through a line item
+ * manager widget (on the order form).
+ */
+function line_item_example_example_2_add_form($element, &$form_state) {
+  $form = array();
+
+  return $form;
+}
+
+/**
+ * Adds the selected product information to a line item added via a line item
+ *   manager widget (on the admin order page).
+ *
+ * @param $line_item
+ *   The newly created line item object.
+ * @param $element
+ *   The array representing the widget form element.
+ * @param $form_state
+ *   The present state of the form upon the latest submission.
+ * @param $form
+ *   The actual form array.
+ *
+ * @return
+ *   NULL if all is well or an error message if something goes wrong.
+ */
+function line_item_example_example_2_add_form_submit(&$line_item, $element, &$form_state, $form) {
+  $line_item->line_item_label = t('Surcharge');
+
+  // Wrap the line item and product to easily set field information.
+  $line_item_wrapper = entity_metadata_wrapper('commerce_line_item', $line_item);
+
+  // Provide a default price.
+  $amount = variable_get('line_item_example_line_item_2_amount', 500);
+  $currency_code = variable_get('line_item_example_line_item_2_currency', 'USD');
+
+  $line_item->commerce_unit_price = array('und' => array(
+    '0' => array('amount' => $amount, 'currency_code' => $currency_code)
+  ));
+
+  if (!is_null($line_item_wrapper->commerce_unit_price->value())) {
+    // Add the base price to the components array.
+    if (!commerce_price_component_load($line_item_wrapper->commerce_unit_price->value(), 'base_price')) {
+      $line_item_wrapper->commerce_unit_price->data = commerce_price_component_add(
+        $line_item_wrapper->commerce_unit_price->value(),
+        'base_price',
+        $line_item_wrapper->commerce_unit_price->value(),
+        TRUE
+      );
+    }
+  }
+
+}
+
+
+/**
+ * Utility function which creates a new example_2 line item populated with the
+ * a price of $5.00, etc..
+ *
+ * @param $order_id
+ *   The ID of the order the line item belongs to (if available).
+ *
+ * @return
+ *   The fully loaded line item..
+ */
+function line_item_example_line_item_2_new($order_id = 0) {
+  $type = 'example_line_item_2';
+
+  // Create the new line item.
+  $line_item = entity_create('commerce_line_item', array(
+    'type' => $type,
+    'order_id' => $order_id,
+    'quantity' => 1,
+  ));
+
+  // For this example, we'll use a price of USD $5.00 for the "surcharge".
+  $amount = variable_get('line_item_example_line_item_2_amount', 500);
+  $currency_code = variable_get('line_item_example_line_item_2_currency', 'USD');
+
+  $line_item->commerce_unit_price = array('und' => array(
+    '0' => array('amount' => $amount, 'currency_code' => $currency_code)
+  ));
+
+  $line_item_wrapper = entity_metadata_wrapper('commerce_line_item', $line_item);
+
+  if (!is_null($line_item_wrapper->commerce_unit_price->value())) {
+    // Add the base price to the components array.
+    if (!commerce_price_component_load($line_item_wrapper->commerce_unit_price->value(), 'base_price')) {
+      $line_item_wrapper->commerce_unit_price->data = commerce_price_component_add(
+        $line_item_wrapper->commerce_unit_price->value(),
+        'base_price',
+        $line_item_wrapper->commerce_unit_price->value(),
+        TRUE
+      );
+    }
+  }
+  // Return the line item.
+  return $line_item;
+}
+
+// There should be one of our example line items on every order, so make sure
+// it's there or add it.
+function line_item_example_commerce_order_presave($order) {
+  // Find out if our order already has an example_2 line item.
+  $type_exists = FALSE;
+  if (!empty($order->commerce_line_items['und'])) {
+    foreach($order->commerce_line_items['und'] as $delta => $line_item_entry) {
+      if ($line_item = commerce_line_item_load($line_item_entry['line_item_id'])) {
+        if ($line_item->type == 'example_line_item_2') {
+          $type_exists = TRUE;
+          break;
+        }
+      }
+    }
+  }
+
+  // If our line item is not yet in the order and the order has an ID,
+  // create a line item to add to the order.
+  if (!$type_exists && $order->order_id > 0) {
+    $line_item = line_item_example_line_item_2_new($order->order_id);
+    commerce_line_item_save($line_item);
+    $order->commerce_line_items['und'][] = array('line_item_id' => $line_item->line_item_id);
+  }
+}
+
 /**
  * Implements hook_commerce_line_item_type_info_alter().
  *