views: Show exception details with the utility to show errors

- Instead of showing traceback details only for action exceptions, show them for
normal exceptions also.

- Also adjust the gap between the error message and the preformatted text to
make it appear better.

Tests:

- Alter code to raise an exception with the utility. See that details are as
expected.

- Raise an exception in a privileged action, ensure that the details shown as
before.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: Veiko Aasa <veiko17@disroot.org>

plinth/views.py

@@ -6,6 +6,7 @@ Main FreedomBox views.
 import datetime
 import random
 import time
+import traceback
 import urllib.parse
 
 from django.contrib import messages
@@ -116,17 +117,20 @@ def messages_error(request, message, exception):
     If an exception can show HTML message, handle is separately.
     """
     if hasattr(exception, 'get_html_message'):
-        collapse_id = 'error-details-' + str(random.randint(0, 10**9))
+        html_message = exception.get_html_message()
-        message = format_html(
+    else:
-            '{message} <a href="#" class="dropdown-toggle" '
+        exception_lines = traceback.format_exception(exception)
-            'data-bs-toggle="collapse" data-bs-target="#{collapse_id}" '
+        html_message = ''.join(exception_lines)
-            'aria-expanded="false" aria-controls="{collapse_id}">'
-            'Details</a><pre class="collapse" '
-            'id="{collapse_id}"><code>{html_message}</code></pre>',
-            message=message, html_message=exception.get_html_message(),
-            collapse_id=collapse_id)
 
-    messages.error(request, message)
+    collapse_id = 'error-details-' + str(random.randint(0, 10**9))
+    formatted_message = format_html(
+        '{message} <a href="#" class="dropdown-toggle" '
+        'data-bs-toggle="collapse" data-bs-target="#{collapse_id}" '
+        'aria-expanded="false" aria-controls="{collapse_id}">'
+        'Details</a><pre class="collapse" '
+        'id="{collapse_id}"><code>{html_message}</code></pre>',
+        message=message, html_message=html_message, collapse_id=collapse_id)
+    messages.error(request, formatted_message)
 
 
 def _get_redirect_url_from_param(request):

static/themes/default/css/main.css

@@ -343,6 +343,10 @@ html {
     max-width: 100%;
 }
 
+.alert pre {
+    margin-top: 1rem;
+}
+
 /* Tags */
 .tag {
     --bs-btn-padding-y: 0.25rem; /* Make the badge shorter */