feat: validate template header logo image format

Author: tmszi

apps/html_template_editor/validators.py

@@ -7,11 +7,19 @@
 def validate_logo_image(image):
     max_width = 300
     megabyte_limit = 5.0 * 1024 * 1024
+    allowed_image_formats = ['JPEG', 'PNG']
 
-    width, height = Image.open(image).size
+    img = Image.open(image)
+    width, height = img.size
     image_file_size = image.tell()
+    image_file_format = img.format
+
+    if image_file_format not in allowed_image_formats:
+        raise ValidationError(
+            _("Allowed image format is %(image_formats)s "),
+            params={'image_formats': ', '.join(allowed_image_formats)},
+        )
 
-    print(width, image_file_size)
     if width > max_width:
         raise ValidationError(
             _("Width is larger than what is allowed %(max_width)s px"),