Initial commit.

Author: JeffTomlinson

README.md

@@ -0,0 +1,2 @@
+# add-attributes-twig-extension
+

add_attributes.function.php

@@ -0,0 +1,90 @@
+<?php
+/**
+ * @file
+ * Add "add_attributes" function for Pattern Lab & Drupal
+ */
+
+use Drupal\Core\Template\Attribute;
+
+$function = new Twig_SimpleFunction('add_attributes', function ($context, $additional_attributes = []) {
+  if (class_exists('Drupal')) {
+    $attributes = new Attribute();
+
+    if (!empty($additional_attributes)) {
+      foreach ($additional_attributes as $key => $value) {
+        if (is_array($value)) {
+          foreach ($value as $index => $item) {
+            // Handle bem() output.
+            if ($item instanceof Attribute) {
+              // Remove the item.
+              unset($value[$index]);
+              $value = array_merge($value, $item->toArray()[$key]);
+            }
+          }
+        }
+        else {
+          // Handle bem() output.
+          if ($value instanceof Attribute) {
+            $value = $value->toArray()[$key];
+          }
+          elseif (is_string($value)) {
+            $value = [$value];
+          }
+          else {
+            continue;
+          }
+        }
+        // Merge additional attribute values with existing ones.
+        if ($context['attributes']->offsetExists($key)) {
+          $existing_attribute = $context['attributes']->offsetGet($key)->value();
+          $value = array_merge($existing_attribute, $value);
+        }
+
+        $context['attributes']->setAttribute($key, $value);
+      }
+    }
+
+    // Set all attributes.
+    foreach($context['attributes'] as $key => $value) {
+      $attributes->setAttribute($key, $value);
+      // Remove this attribute from context so it doesn't filter down to child
+      // elements.
+      $context['attributes']->removeAttribute($key);
+    }
+
+    return $attributes;
+  }
+  // Pattern Lab.
+  else {
+    $attributes = [];
+
+    foreach ($additional_attributes as $key => $value) {
+      if (is_array($value)) {
+        foreach ($value as $index => $item) {
+          // Handle bem() output.
+          if (strpos($item, $key . '=') !== FALSE) {
+            parse_str($item, $result);
+            // Remove the item.
+            unset($value[$index]);
+            // Strip surrounding quotes.
+            $value[] = substr($result[$key], 1, -1);
+          }
+        }
+
+        $attributes[] = $key . '="' . implode(' ', $value) . '"';
+      }
+      else {
+        // Handle bem() output.
+        if (strpos($value, $key . '=') !== FALSE) {
+          $attributes[] = $value;
+        }
+        else {
+          $attributes[] = $key . '="' . $value . '"';
+        }
+      }
+    }
+
+    return implode(' ', $attributes);
+  }
+
+}, array('needs_context' => true, 'is_safe' => array('html')));