Add a placeholder for the HTML5 picture element (#115)

Author: LukeLeber

Diff for: lib/Caxy/HtmlDiff/HtmlDiff.php

@@ -333,6 +333,8 @@ protected function diffIsolatedPlaceholder($operation, $pos, $placeholder, $stri
             return $this->diffElementsByAttribute($oldText, $newText, 'href', 'a');
         } elseif ($this->isImagePlaceholder($placeholder)) {
             return $this->diffElementsByAttribute($oldText, $newText, 'src', 'img');
+        } elseif ($this->isPicturePlaceholder($placeholder)) {
+           return $this->diffPicture($oldText, $newText);
         }
 
         return $this->diffElements($oldText, $newText, $stripWrappingTags);
@@ -393,6 +395,23 @@ protected function diffTables($oldText, $newText)
         return $diff->build();
     }
 
+    /**
+     * @param string $oldText
+     * @param string $newText
+     *
+     * @return string
+     */
+    protected function diffPicture($oldText, $newText) {
+        if ($oldText !== $newText) {
+            return sprintf(
+                '%s%s',
+                $this->wrapText($oldText, 'del', 'diffmod'),
+                $this->wrapText($newText, 'ins', 'diffmod')
+            );
+        }
+        return $this->diffElements($oldText, $newText);
+  }
+
     protected function diffElementsByAttribute($oldText, $newText, $attribute, $element)
     {
         $oldAttribute = $this->getAttributeFromTag($oldText, $attribute);
@@ -475,6 +494,11 @@ public function isImagePlaceholder($text)
         return $this->isPlaceholderType($text, 'img');
     }
 
+    public function isPicturePlaceholder($text)
+    {
+        return $this->isPlaceholderType($text, 'picture');
+    }
+
     /**
      * @param string       $text
      * @param array|string $types

Diff for: lib/Caxy/HtmlDiff/HtmlDiffConfig.php

@@ -50,6 +50,7 @@ class HtmlDiffConfig
         'a' => '[[REPLACE_A]]',
         'img' => '[[REPLACE_IMG]]',
         'pre' => '[[REPLACE_PRE]]',
+        'picture' => '[[REPLACE_PICTURE]]',
     );
 
     /**