fixes to tokens

changedetectionio/forms.py

@@ -220,9 +220,10 @@ class ValidateJinja2Template(object):
                 f"The following tokens used in the notification are not valid: {undefined}"
             )
 
-        regex = re.compile('{.*?}')
+        regex = re.compile('{{(.*?)}}')
+        valid_tokens = list(notification.valid_tokens.keys())
         for p in re.findall(regex, field.data):
-            if not p.strip('{}') in notification.valid_tokens:
+            if not p.strip() in valid_tokens:
                 message = field.gettext('Token \'%s\' is not a valid token.')
                 raise ValidationError(message % (p))
             

changedetectionio/templates/_common_fields.jinja

@@ -85,7 +85,7 @@
                                         <td>The diff output - differences only</td>
                                     </tr>
                                     <tr>
-                                        <td><code>{{ '{diff_full}' }}</code></td>
+                                        <td><code>{{ '{{ diff_full }}' }}</code></td>
                                         <td>The diff output - full difference output</td>
                                     </tr>
                                     <tr>