callbacks triggering

docs/source/index.rst

@@ -54,7 +54,7 @@ Registering callbacks
 
     class MyCallback(Callback):
 
-        def callback(self):
+        def trigger(self):
             print("Mail received: {O}".format(self.subject))
 
     register(MyCallback)
@@ -79,7 +79,7 @@ pattern 'Hello ' followed by a word, anywhere in the subject (it uses
     class MyCallback(Callback):
         rules = {'subject': [r'Hello (\w)']}
 
-        def callback(self):
+        def trigger(self):
             print("Mail received for {0}".format(self.matches['subject'][0]))
 
     register(MyCallback)
@@ -101,7 +101,7 @@ registering:
 
     class MyCallback(Callback):
 
-        def callback(self):
+        def trigger(self):
             print("Mail received for %s!" self.matches['subject'][0])
 
     register(MyCallback, rules={'subject': [r'Hello (\w)']})
@@ -176,7 +176,7 @@ As an example, let's take an email with the subject "Hello Bryan", from
     class MyCallback(Callback):
         rules = {'subject': [r'Hello (\w)', 'Hi!'], 'from': ['@doe.com']}
 
-        def callback(self):
+        def trigger(self):
             print("Mail received for {0}".format(self.matches['subject'][0]))
 
     register(MyCallback)

mailbot/callback.py

@@ -53,6 +53,12 @@ class Callback(object):
         return any(self.matches[item])
 
     def get_email_body(self, message=None):
+        """Return the message text body.
+
+        Return the first 'text/plain' part of the email.Message that doesn't
+        have a filename.
+
+        """
         if message is None:
             message = self.message
 
@@ -65,3 +71,8 @@ class Callback(object):
             if content_type == 'text/plain' and filename is None:
                 # text body of the mail, not an attachment
                 return part.get_payload()
+        return ''
+
+    def trigger(self):
+        """Called when a mail matching the registered rules is received."""
+        raise NotImplementedError("Must be implemented in a child class.")

mailbot/mailbot.py

@@ -35,7 +35,7 @@ class MailBot(object):
         """Check if callback matches rules, and if so, trigger."""
         callback = callback_class(message, rules)
         if callback.check_rules():
-            return callback.callback()
+            return callback.trigger()
 
     def process_messages(self):
         """Process messages: check which callbacks should be triggered."""

mailbot/tests/test_callback.py

@@ -4,7 +4,7 @@ from email import message_from_file, message_from_string
 from os import path
 from re import search
 
-from mock import sentinel, Mock
+from mock import Mock
 
 from . import MailBotTestCase
 from .. import Callback
@@ -80,10 +80,21 @@ class CallbackTest(MailBotTestCase):
         self.assertEqual(callback.get_email_body(), None)  # not a Message
         self.assertEqual(callback.get_email_body('foo'), None)  # not a Message
 
+        # empty email
         empty_message = message_from_string('')
         self.assertEqual(callback.get_email_body(empty_message), '')
 
+        # badly formed email without a 'text/plain' part
+        empty_message.set_type('html/plain')
+        self.assertEqual(callback.get_email_body(empty_message), '')
+
+        # real email
         email_file = path.join(path.dirname(__file__),
                                'mails/mail_with_attachment.txt')
         email = message_from_file(open(email_file, 'r'))
         self.assertEqual(callback.get_email_body(email), 'Mail content here\n')
+
+    def test_trigger(self):
+        callback = Callback('foo', 'bar')
+
+        self.assertRaises(NotImplementedError, callback.trigger)

mailbot/tests/test_mailbot.py

@@ -56,7 +56,7 @@ class MailBotTest(MailBotClientTest):
     def test_process_message_trigger(self):
         callback = Mock()
         callback.check_rules.return_value = True
-        callback.callback.return_value = sentinel.callback_result
+        callback.trigger.return_value = sentinel.callback_result
         callback_class = Mock(return_value=callback)
 
         res = self.bot.process_message(sentinel.message, callback_class,
@@ -65,7 +65,7 @@ class MailBotTest(MailBotClientTest):
         callback_class.assert_called_once_with(sentinel.message,
                                                sentinel.rules)
         callback.check_rules.assert_called_once_with()
-        callback.callback.assert_called_once_with()
+        callback.trigger.assert_called_once_with()
         self.assertEqual(res, sentinel.callback_result)
 
     def test_process_message_no_trigger(self):