Add a send_email function that takes a template_prefix and context.

This commit replaces all uses of django.core.mail.send_mail with send_email,
other than in the password reset flow, since that code looks like it is just
a patch to Django's password reset code.

The send_email function is in a new file, since putting it in
zerver.lib.notifications would create an import loop with confirmation.models.

send_future_email will soon be moved into email.py as well.

confirmation/models.py

@@ -8,15 +8,14 @@ import re
 
 from django.db import models
 from django.core.urlresolvers import reverse
-from django.core.mail import send_mail
 from django.conf import settings
-from django.template import loader, Context, TemplateDoesNotExist
 from django.contrib.sites.models import Site
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes.fields import GenericForeignKey
 from django.utils.timezone import now as timezone_now
 
 from confirmation.util import get_status_field
+from zerver.lib.send_email import send_email
 from zerver.lib.utils import generate_random_token
 from zerver.models import PreregistrationUser, EmailChangeStatus
 from typing import Any, Dict, Optional, Text, Union
@@ -91,31 +90,24 @@ class ConfirmationManager(models.Manager):
         # type: () -> int
         return getattr(settings, 'EMAIL_CONFIRMATION_DAYS', 10)
 
-    def send_confirmation(self, obj, template_prefix, email_address, additional_context=None,
+    def send_confirmation(self, obj, template_prefix, to_email, additional_context=None,
                           host=None, custom_body=None):
         # type: (ContentType, str, Text, Optional[Dict[str, Any]], Optional[str], Optional[str]) -> Confirmation
         confirmation_key = generate_key()
         current_site = Site.objects.get_current()
         activate_url = self.get_activation_url(confirmation_key, host=host)
-        context = Context({
+        context = {
             'activate_url': activate_url,
             'current_site': current_site,
             'confirmation_key': confirmation_key,
             'target': obj,
             'days': getattr(settings, 'EMAIL_CONFIRMATION_DAYS', 10),
             'custom_body': custom_body,
-        })
+        }
         if additional_context is not None:
             context.update(additional_context)
 
-        subject = loader.render_to_string(template_prefix + '.subject', context).strip()
-        body = loader.render_to_string(template_prefix + '.txt', context)
-        try:
-            html_content = loader.render_to_string(template_prefix + '.html', context)
-        except TemplateDoesNotExist:
-            html_content = None
-
-        send_mail(subject, body, settings.DEFAULT_FROM_EMAIL, [email_address], html_message=html_content)
+        send_email(template_prefix, to_email, from_email=settings.DEFAULT_FROM_EMAIL, context=context)
         return self.create(content_object=obj, date_sent=timezone_now(), confirmation_key=confirmation_key)
 
 class EmailChangeConfirmationManager(ConfirmationManager):

zerver/lib/send_email.py

@@ -0,0 +1,29 @@
+from django.conf import settings
+from django.core.mail import send_mail
+from django.template import loader, TemplateDoesNotExist
+from zerver.models import UserProfile
+
+from typing import Dict, List, Optional, Text
+
+def display_email(user):
+    # type: (UserProfile) -> Text
+    # Change to '%s <%s>' % (user.full_name, user.email) once
+    # https://github.com/zulip/zulip/issues/4676 is resolved
+    return user.email
+
+def send_email(template_prefix, to_email, from_email=None, context={}):
+    # type: (str, Text, Optional[Text], Dict[str, Any]) -> bool
+    subject = loader.render_to_string(template_prefix + '.subject', context).strip()
+    message = loader.render_to_string(template_prefix + '.txt', context)
+    # Remove try/expect once https://github.com/zulip/zulip/issues/4691 is resolved.
+    try:
+        html_message = loader.render_to_string(template_prefix + '.html', context)
+    except TemplateDoesNotExist:
+        html_message = None
+    if from_email is None:
+        from_email = settings.NOREPLY_EMAIL_ADDRESS
+    return send_mail(subject, message, from_email, [to_email], html_message=html_message) > 0
+
+def send_email_to_user(template_prefix, user, from_email=None, context={}):
+    # type: (str, UserProfile, Optional[Text], Dict[str, Text]) -> bool
+    return send_email(template_prefix, display_email(user), from_email=from_email, context=context)

zerver/management/commands/send_password_reset_email.py

@@ -65,6 +65,9 @@ class Command(BaseCommand):
             }
 
             logging.warning("Sending %s email to %s" % (email_template_name, user_profile.email,))
+            # Our password reset flow is basically a patch of Django's password
+            # reset flow, so this is aligned with Django code rather than using
+            # zerver.lib.send_email.send_email.
             self.send_email(subject_template_name, email_template_name,
                             context, from_email, user_profile.email,
                             html_email_template_name=html_email_template_name)

zerver/signals.py

@@ -2,12 +2,12 @@ from __future__ import absolute_import
 
 from django.dispatch import receiver
 from django.contrib.auth.signals import user_logged_in
-from django.core.mail import send_mail
 from django.conf import settings
 from django.template import loader
 from django.utils.timezone import get_current_timezone_name as timezone_get_current_timezone_name
 from django.utils.timezone import now as timezone_now
 from typing import Any, Dict, Optional
+from zerver.lib.send_email import send_email_to_user
 from zerver.models import UserProfile
 
 def get_device_browser(user_agent):
@@ -85,10 +85,4 @@ def email_on_new_login(sender, user, request, **kwargs):
         context['zulip_support'] = settings.ZULIP_ADMINISTRATOR
         context['user'] = user
 
-        text_content = loader.render_to_string('zerver/emails/notify_new_login.txt', context)
-        html_content = loader.render_to_string('zerver/emails/notify_new_login.html', context)
-
-        sender = settings.NOREPLY_EMAIL_ADDRESS
-        recipients = [user.email]
-        subject = loader.render_to_string('zerver/emails/notify_new_login.subject').strip()
-        send_mail(subject, text_content, sender, recipients, html_message=html_content)
+        send_email_to_user('zerver/emails/notify_new_login', user, context=context)

zerver/views/registration.py

@@ -12,11 +12,11 @@ from django.template import RequestContext, loader
 from django.utils.timezone import now
 from django.core.exceptions import ValidationError
 from django.core import validators
-from django.core.mail import send_mail
 from zerver.models import UserProfile, Realm, PreregistrationUser, \
     name_changes_disabled, email_to_username, \
     completely_open, get_unique_open_realm, email_allowed_for_realm, \
     get_realm, get_realm_by_email_domain
+from zerver.lib.send_email import send_email_to_user
 from zerver.lib.events import do_events_register
 from zerver.lib.actions import do_change_password, do_change_full_name, do_change_is_admin, \
     do_activate_user, do_create_user, do_create_realm, set_default_streams, \
@@ -390,17 +390,6 @@ def generate_204(request):
     # type: (HttpRequest) -> HttpResponse
     return HttpResponse(content=None, status=204)
 
-def send_find_my_team_emails(user_profile):
-    # type: (UserProfile) -> None
-    context = {'user_profile': user_profile}
-    text_content = loader.render_to_string('zerver/emails/find_team.txt', context)
-    html_content = loader.render_to_string('zerver/emails/find_team.html', context)
-    sender = settings.NOREPLY_EMAIL_ADDRESS
-    recipients = [user_profile.email]
-    subject = loader.render_to_string('zerver/emails/find_team.subject').strip()
-
-    send_mail(subject, text_content, sender, recipients, html_message=html_content)
-
 def find_my_team(request):
     # type: (HttpRequest) -> HttpResponse
     url = reverse('zerver.views.registration.find_my_team')
@@ -411,7 +400,8 @@ def find_my_team(request):
         if form.is_valid():
             emails = form.cleaned_data['emails']
             for user_profile in UserProfile.objects.filter(email__in=emails):
-                send_find_my_team_emails(user_profile)
+                send_email_to_user('zerver/emails/find_team', user_profile,
+                                   context={'user_profile': user_profile})
 
             # Note: Show all the emails in the result otherwise this
             # feature can be used to ascertain which email addresses

zerver/views/user_settings.py

@@ -5,10 +5,8 @@ from typing import Dict, Text
 from django.utils.translation import ugettext as _
 from django.conf import settings
 from django.contrib.auth import authenticate, update_session_auth_hash
-from django.core.mail import send_mail
 from django.http import HttpRequest, HttpResponse
 from django.shortcuts import redirect, render
-from django.template.loader import render_to_string
 from django.urls import reverse
 
 from zerver.decorator import authenticated_json_post_view, has_request_variables, \
@@ -24,6 +22,7 @@ from zerver.lib.actions import do_change_password, \
     do_change_pm_content_in_desktop_notifications, validate_email, \
     do_change_user_email, do_start_email_change_process
 from zerver.lib.avatar import avatar_url
+from zerver.lib.send_email import send_email, display_email
 from zerver.lib.i18n import get_available_language_codes
 from zerver.lib.response import json_success, json_error
 from zerver.lib.upload import upload_avatar_image
@@ -59,11 +58,8 @@ def confirm_email_change(request, confirmation_key):
                    'realm': obj.realm,
                    'new_email': new_email,
                    }
-        subject = render_to_string(
-            'zerver/emails/notify_change_in_email.subject', context)
-        body = render_to_string(
-            'zerver/emails/notify_change_in_email.txt', context)
-        send_mail(subject, body, settings.DEFAULT_FROM_EMAIL, [old_email])
+        send_email('zerver/emails/notify_change_in_email', old_email,
+                   from_email=settings.DEFAULT_FROM_EMAIL, context=context)
 
     ctx = {
         'confirmed': confirmed,