--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/detectors/immutable_file_contents.py	Tue Mar 24 22:11:27 2026 -0400
@@ -0,0 +1,22 @@
+# HTML pages don't provide a way to change the contents of a file.
+# However REST does allow setting content and the HTML interface can
+# be directed to update the content as well. This detector
+# prevents changes to file content.
+
+from roundup.exceptions import UsageError
+
+def immutable_file_contents(db, cl, nodeid, newvalues):
+    ''' Prevent content changes to a file
+    '''
+    if 'content' in newvalues:
+        raise UsageError("File contents are immutable. "
+                         "Rejecting change to contents.")
+
+
+def init(db):
+    """If you have other FileClass based classes add them here."""
+
+    # fire before changes are made
+    db.file.audit('set', immutable_file_contents)
+    db.msg.audit('set', immutable_file_contents)
+