refactored MailSender to get rid of scrapy.conf singleton, also removed ill-designed scrapy.mail.mail_sent signal

docs/news.rst

@@ -32,6 +32,7 @@ Scrapy changes:
 - LogFormatter method now return dicts(instead of strings) to support lazy formatting (:issue:`164`, :commit:`dcef7b0`)
 - downloader handlers (:setting:`DOWNLOAD_HANDLERS` setting) now receive settings as the first argument of the constructor
 - replaced memory usage acounting with (more portable) `resource`_ module, removed ``scrapy.utils.memory`` module
+- removed signal: ``scrapy.mail.mail_sent``
 
 Scrapyd changes:
 

docs/topics/email.rst

@@ -20,11 +20,19 @@ simple API for sending attachments and it's very easy to configure, with a few
 Quick example
 =============
 
-Here's a quick example of how to send an e-mail (without attachments)::
+There are two ways to instantiate the mail sender. You can instantiate it using
+the standard constructor::
 
     from scrapy.mail import MailSender
-
     mailer = MailSender()
+
+Or you can instantiate it passing a Scrapy settings object, which will respect
+the :ref:`settings <topics-email-settings>`::
+
+    mailer = MailSender.from_settings(settings)
+
+And here is how to use it to send an e-mail (without attachments)::
+
     mailer.send(to=["someone@example.com"], subject="Some subject", body="Some body", cc=["another@example.com"])
 
 MailSender class reference
@@ -33,7 +41,7 @@ MailSender class reference
 MailSender is the preferred class to use for sending emails from Scrapy, as it
 uses `Twisted non-blocking IO`_, like the rest of the framework. 
 
-.. class:: MailSender(smtphost=None, mailfrom=None, smtpuser=None, smtppass=None, smtpport=None):
+.. class:: MailSender(smtphost=None, mailfrom=None, smtpuser=None, smtppass=None, smtpport=None)
 
     :param smtphost: the SMTP host to use for sending the emails. If omitted, the 
       :setting:`MAIL_HOST` setting will be used.
@@ -54,9 +62,17 @@ uses `Twisted non-blocking IO`_, like the rest of the framework.
     :param smtpport: the SMTP port to connect to
     :type smtpport: int
 
+    .. classmethod:: from_settings(settings)
+
+        Instantiate using a Scrapy settings object, which will respect
+        :ref:`these Scrapy settings <topics-email-settings>`.
+
+        :param settings: the e-mail recipients
+        :type settings: :class:`scrapy.settings.Settings` object
+
     .. method:: send(to, subject, body, cc=None, attachs=())
 
-        Send email to the given recipients. Emits the :signal:`mail_sent` signal.
+        Send email to the given recipients.
 
         :param to: the e-mail recipients
         :type to: list
@@ -132,34 +148,3 @@ MAIL_PASS
 Default: ``None``
 
 Password to use for SMTP authentication, along with :setting:`MAIL_USER`.
-
-
-Mail signals
-============
-
-.. signal:: mail_sent
-.. function:: mail_sent(to, subject, body, cc, attachs, msg)
-
-  Emitted by :meth:`MailSender.send` after an email has been sent.
-
-  :param to: the e-mail recipients
-  :type to: list
-
-  :param subject: the subject of the e-mail
-  :type subject: str
-
-  :param cc: the e-mails to CC
-  :type cc: list
-
-  :param body: the e-mail body
-  :type body: str
-
-  :param attachs: an iterable of tuples ``(attach_name, mimetype,
-    file_object)`` where  ``attach_name`` is a string with the name that will
-    appear on the e-mail's attachment, ``mimetype`` is the mimetype of the
-    attachment and ``file_object`` is a readable file object with the
-    contents of the attachment
-  :type attachs: iterable
-
-  :param msg: the generated message
-  :type msg: ``MIMEMultipart`` or ``MIMENonMultipart``

scrapy/contrib/memusage.py

@@ -30,7 +30,7 @@ class MemoryUsage(object):
         self.limit = crawler.settings.getint('MEMUSAGE_LIMIT_MB')*1024*1024
         self.warning = crawler.settings.getint('MEMUSAGE_WARNING_MB')*1024*1024
         self.report = crawler.settings.getbool('MEMUSAGE_REPORT')
-        self.mail = MailSender()
+        self.mail = MailSender.from_settings(crawler.settings)
         crawler.signals.connect(self.engine_started, signal=signals.engine_started)
         crawler.signals.connect(self.engine_stopped, signal=signals.engine_stopped)
 

scrapy/contrib/statsmailer.py

@@ -10,23 +10,25 @@ from scrapy.exceptions import NotConfigured
 
 class StatsMailer(object):
 
-    def __init__(self, stats, recipients):
+    def __init__(self, stats, recipients, mail):
         self.stats = stats
         self.recipients = recipients
+        self.mail = mail
 
     @classmethod
     def from_crawler(cls, crawler):
         recipients = crawler.settings.getlist("STATSMAILER_RCPTS")
         if not recipients:
             raise NotConfigured
-        o = cls(crawler.stats, recipients)
-        crawler.connect(o.stats_spider_closed, signal=signals.stats_spider_closed)
+        mail = MailSender.from_settings(crawler.settings)
+        o = cls(crawler.stats, recipients, mail)
+        crawler.signals.connect(o.spider_closed, signal=signals.spider_closed)
         return o
         
-    def stats_spider_closed(self, spider, spider_stats):
-        mail = MailSender()
+    def spider_closed(self, spider):
+        spider_stats = self.stats.get_stats(spider)
         body = "Global stats\n\n"
         body += "\n".join("%-50s : %s" % i for i in self.stats.get_stats().items())
         body += "\n\n%s stats\n\n" % spider.name
         body += "\n".join("%-50s : %s" % i for i in spider_stats.items())
-        mail.send(self.recipients, "Scrapy stats for: %s" % spider.name, body)
+        return self.mail.send(self.recipients, "Scrapy stats for: %s" % spider.name, body)

scrapy/mail.py

@@ -15,31 +15,24 @@ from twisted.internet import defer, reactor
 from twisted.mail.smtp import ESMTPSenderFactory
 
 from scrapy import log
-from scrapy.exceptions import NotConfigured
-from scrapy.conf import settings
-
-
-# signal sent when message is sent
-# args: to, subject, body, cc, attach, msg
-mail_sent = object()
-
 
 class MailSender(object):
 
-    def __init__(self, smtphost=None, mailfrom=None, smtpuser=None, smtppass=None, \
-            smtpport=None, debug=False, crawler=None):
-        self.smtphost = smtphost or settings['MAIL_HOST']
-        self.smtpport = smtpport or settings.getint('MAIL_PORT')
-        self.smtpuser = smtpuser or settings['MAIL_USER']
-        self.smtppass = smtppass or settings['MAIL_PASS']
-        self.mailfrom = mailfrom or settings['MAIL_FROM']
+    def __init__(self, smtphost='localhost', mailfrom='scrapy@localhost',
+            smtpuser=None, smtppass=None, smtpport=25, debug=False):
+        self.smtphost = smtphost
+        self.smtpport = smtpport
+        self.smtpuser = smtpuser
+        self.smtppass = smtppass
+        self.mailfrom = mailfrom
         self.debug = debug
-        self.signals = crawler.signals if crawler else None
 
-        if not self.smtphost or not self.mailfrom:
-            raise NotConfigured("MAIL_HOST and MAIL_FROM settings are required")
+    @classmethod
+    def from_settings(cls, settings):
+        return cls(settings['MAIL_HOST'], settings['MAIL_FROM'], settings['MAIL_USER'],
+            settings['MAIL_PASS'], settings.getint('MAIL_PORT'))
 
-    def send(self, to, subject, body, cc=None, attachs=()):
+    def send(self, to, subject, body, cc=None, attachs=(), _callback=None):
         if attachs:
             msg = MIMEMultipart()
         else:
@@ -65,9 +58,8 @@ class MailSender(object):
         else:
             msg.set_payload(body)
 
-        if self.signals:
-            self.signals.send_catch_log(signal=mail_sent, to=to, subject=subject, body=body,
-                       cc=cc, attach=attachs, msg=msg)
+        if _callback:
+            _callback(to=to, subject=subject, body=body, cc=cc, attach=attachs, msg=msg)
 
         if self.debug:
             log.msg(format='Debug mail sent OK: To=%(mailto)s Cc=%(mailcc)s Subject="%(mailsubject)s" Attachs=%(mailattachs)d',

scrapy/tests/test_mail.py

@@ -1,23 +1,13 @@
 from cStringIO import StringIO
 import unittest
 
-from scrapy.mail import MailSender, mail_sent
-from scrapy.utils.test import get_crawler
-
+from scrapy.mail import MailSender
 
 class MailSenderTest(unittest.TestCase):
 
-    def setUp(self):
-        self.catched_msg = None
-        self.crawler = get_crawler()
-        self.crawler.signals.connect(self._catch_mail_sent, signal=mail_sent)
-
-    def tearDown(self):
-        self.crawler.signals.disconnect(self._catch_mail_sent, signal=mail_sent)
-
     def test_send(self):
-        mailsender = MailSender(debug=True, crawler=self.crawler)
-        mailsender.send(to=['test@scrapy.org'], subject='subject', body='body')
+        mailsender = MailSender(debug=True)
+        mailsender.send(to=['test@scrapy.org'], subject='subject', body='body', _callback=self._catch_mail_sent)
 
         assert self.catched_msg
 
@@ -36,9 +26,9 @@ class MailSenderTest(unittest.TestCase):
         attach.seek(0)
         attachs = [('attachment', 'text/plain', attach)]
 
-        mailsender = MailSender(debug=True, crawler=self.crawler)
+        mailsender = MailSender(debug=True)
         mailsender.send(to=['test@scrapy.org'], subject='subject', body='body',
-                       attachs=attachs)
+                       attachs=attachs, _callback=self._catch_mail_sent)
 
         assert self.catched_msg
         self.assertEqual(self.catched_msg['to'], ['test@scrapy.org'])