added TracebackMiddleware

1 files changed, 20 insertions, 0 deletions

diff --git a/wsgitools/middlewares.py b/wsgitools/middlewares.py
index 9eab2a1..ea61aca 100644
--- a/wsgitools/middlewares.py
+++ b/wsgitools/middlewares.py
@@ -1,6 +1,8 @@
 __all__ = []
 
 import time
+import sys
+import cgitb
 from filters import CloseableList, CloseableIterator
 try:
     import cStringIO as StringIO
@@ -265,3 +267,21 @@ class BasicAuthMiddleware:
         headers.append(('Content-length', len(html)))
         start_response(status, headers)
         return [html]
+
+__all__.append("TracebackMiddleware")
+class TracebackMiddleware:
+    """In case the application throws an exception this middleware will show an
+    html-formatted traceback using cgitb."""
+    def __init__(self, app):
+        """app is the wsgi application to proxy."""
+        self.app = app
+    def __call__(self, environ, start_response):
+        """wsgi interface"""
+        try:
+	    return self.app(environ, start_response)
+	except:
+	    exc_info = sys.exc_info()
+	    data = cgitb.html(exc_info)
+	    start_response("200 OK", [("Content-type", "text/html"),
+	                              ("Content-length", str(len(data)))])
+            return [data]