Added better error handling to mailgw.

Author: Richard Jones

roundup/mailgw.py

@@ -72,14 +72,17 @@ class node. Any parts of other types are each stored in separate files
 an exception, the original message is bounced back to the sender with the
 explanatory message given in the exception. 
 
-$Id: mailgw.py,v 1.11 2001-08-08 00:08:03 richard Exp $
+$Id: mailgw.py,v 1.12 2001-08-08 01:27:00 richard Exp $
 '''
 
 
 import string, re, os, mimetools, cStringIO, smtplib, socket, binascii, quopri
 import traceback
 import date
 
+class MailUsageError(ValueError):
+    pass
+
 class Message(mimetools.Message):
     ''' subclass mimetools.Message so we can retrieve the parts of the
         message...
@@ -121,8 +124,17 @@ def main(self, fp):
         '''
         # ok, figure the subject, author, recipients and content-type
         message = Message(fp)
+        m = []
         try:
             self.handle_message(message)
+        except MailUsageError, value:
+            # bounce the message back to the sender with the usage message
+            fulldoc = '\n'.join(string.split(__doc__, '\n')[2:])
+            sendto = [message.getaddrlist('from')[0][1]]
+            m = ['Subject: Failed issue tracker submission', '']
+            m.append(str(value))
+            m.append('\nMail Gateway Help\n=================')
+            m.append(fulldoc)
         except:
             # bounce the message back to the sender with the error message
             sendto = [message.getaddrlist('from')[0][1]]
@@ -140,6 +152,7 @@ def main(self, fp):
             except:
                 pass
             m.append(fp.read())
+        if m:
             try:
                 smtp = smtplib.SMTP(self.MAILHOST)
                 smtp.sendmail(self.ADMIN_EMAIL, sendto, '\n'.join(m))
@@ -157,12 +170,33 @@ def handle_message(self, message):
         subject = message.getheader('subject')
         m = subject_re.match(subject)
         if not m:
-            raise ValueError, 'No [designator] found in subject "%s"'%subject
+            raise MailUsageError, '''
+The message you sent to roundup did not contain a properly formed subject
+line. The subject must contain a class name or designator to indicate the
+"topic" of the message. For example:
+    Subject: [issue] This is a new issue
+      - this will create a new issue in the tracker with the title "This is
+        a new issue".
+    Subject: [issue1234] This is a followup to issue 1234
+      - this will append the message's contents to the existing issue 1234
+        in the tracker.
+
+Subject was: "%s"
+'''%subject
         classname = m.group('classname')
         nodeid = m.group('nodeid')
         title = m.group('title').strip()
         subject_args = m.group('args')
-        cl = self.db.getclass(classname)
+        try:
+            cl = self.db.getclass(classname)
+        except KeyError:
+            raise MailUsageError, '''
+The class name you identified in the subject line ("%s") does not exist in the
+database.
+
+Valid class names are: %s
+Subject was: "%s"
+'''%(classname, ', '.join(self.db.getclasses()), subject)
         properties = cl.getprops()
         props = {}
         args = m.group('args')
@@ -171,8 +205,20 @@ def handle_message(self, message):
                 try:
                     key, value = prop.split('=')
                 except ValueError, message:
-                    raise ValueError, 'Args list not of form [arg=value,value,...;arg=value,value,value..]  (specific exception message was "%s")'%message
-                type =  properties[key]
+                    raise MailUsageError, '''
+Subject argument list not of form [arg=value,value,...;arg=value,value...]
+   (specific exception message was "%s")
+
+Subject was: "%s"
+'''%(message, subject)
+                try:
+                    type =  properties[key]
+                except KeyError:
+                    raise MailUsageError, '''
+Subject argument list refers to an invalid property: "%s"
+
+Subject was: "%s"
+'''%(key, subject)
                 if type.isStringType:
                     props[key] = value 
                 elif type.isDateType:
@@ -237,7 +283,10 @@ def handle_message(self, message):
                     attachments.append((name, part.gettype(), data))
 
             if content is None:
-                raise ValueError, 'No text/plain part found'
+                raise MailUsageError, '''
+Roundup requires the submission to be plain text. The message parser could
+not find a text/plain part o use.
+'''
 
         elif content_type[:10] == 'multipart/':
             # skip over the intro to the first boundary
@@ -253,10 +302,16 @@ def handle_message(self, message):
                     # this one's our content
                     content = part.fp.read()
             if content is None:
-                raise ValueError, 'No text/plain part found'
+                raise MailUsageError, '''
+Roundup requires the submission to be plain text. The message parser could
+not find a text/plain part o use.
+'''
 
         elif content_type != 'text/plain':
-            raise ValueError, 'No text/plain part found'
+            raise MailUsageError, '''
+Roundup requires the submission to be plain text. The message parser could
+not find a text/plain part o use.
+'''
 
         else:
             content = message.fp.read()
@@ -278,7 +333,15 @@ def handle_message(self, message):
             message_id = self.db.msg.create(author=author,
                 recipients=recipients, date=date.Date('.'), summary=summary,
                 content=content, files=files)
-            messages = cl.get(nodeid, 'messages')
+            try:
+                messages = cl.get(nodeid, 'messages')
+            except IndexError:
+                raise MailUsageError, '''
+The node specified by the designator in the subject of your message ("%s")
+does not exist.
+
+Subject was: "%s"
+'''%(nodeid, subject)
             messages.append(message_id)
             props['messages'] = messages
             cl.set(nodeid, **props)
@@ -335,6 +398,9 @@ def parseContent(content, blank_line=re.compile(r'[\r\n]+\s*[\r\n]+'),
 
 #
 # $Log: not supported by cvs2svn $
+# Revision 1.11  2001/08/08 00:08:03  richard
+# oops ;)
+#
 # Revision 1.10  2001/08/07 00:24:42  richard
 # stupid typo
 #