Ticket 784: traceback (#1474)

* 'traceback' is already formatted

* add debug / example code for full tracebacks

autobahn/wamp/exception.py

@@ -282,7 +282,7 @@ def error_message(self):
 
     def __unicode__(self):
         if self.kwargs and 'traceback' in self.kwargs:
-            tb = ':\n' + '\n'.join(self.kwargs.pop('traceback')) + '\n'
+            tb = ':\n' + self.kwargs.pop('traceback') + '\n'
             self.kwargs['traceback'] = '...'
         else:
             tb = ''

examples/twisted/wamp/component/backend.py

@@ -56,6 +56,9 @@
 @component.on_join
 def join(session, details):
     print("joined {}: {}".format(session, details))
+    # if you want full tracbacks on the client-side, you enable that
+    # here:
+    # session.traceback_app = True
 
 
 @component.register(
@@ -64,6 +67,7 @@ def join(session, details):
 )
 @inlineCallbacks
 def foo(*args, **kw):
+    # raise RuntimeError("bad stuff")
     print("foo({}, {})".format(args, kw))
     for x in range(5, 0, -1):
         print("  returning in {}".format(x))

examples/twisted/wamp/component/frontend.py

@@ -32,7 +32,13 @@ def main(reactor, session):
         print("prefix-match 'prefix.fail.' failed as expected: {}".format(e.error))
 
     print("calling 'example.foo'")
-    res = yield session.call("example.foo")
+    try:
+        res = yield session.call("example.foo")
+    except Exception as e:
+        # to see errors uncomment the "throw" in backend .. also try
+        # with .traceback_app enabled (in the backend)
+        print("Error from 'example.foo' call:")
+        print(e)
     print("example.foo() = {}".format(res))
 
     print("done")