feat: Send welcome email from template

breccia_mapper/settings.py

@@ -157,6 +157,7 @@ THIRD_PARTY_APPS = [
     'django_countries',
     'django_select2',
     'rest_framework',
+    'post_office',
 ]
 
 FIRST_PARTY_APPS = [
@@ -378,12 +379,15 @@ else:
 
 # Import customisation app settings if present
 
+CUSTOMISATION_NAME = None
 TEMPLATE_NAME_INDEX = 'index.html'
+TEMPLATE_WELCOME_EMAIL_NAME = 'welcome-email'
 
 try:
     from custom.settings import (
         CUSTOMISATION_NAME,
-        TEMPLATE_NAME_INDEX
+        TEMPLATE_NAME_INDEX,
+        TEMPLATE_WELCOME_EMAIL_NAME
     )
     logger.info("Loaded customisation app: %s", CUSTOMISATION_NAME)
 

people/__init__.py

@@ -0,0 +1 @@
+default_app_config = 'people.apps.PeopleConfig'

people/apps.py

@@ -1,5 +1,63 @@
+import logging
+
 from django.apps import AppConfig
+from django.conf import settings
+from django.core import serializers
+from django.db.models.signals import post_save
+
+logger = logging.getLogger(__name__)
+
+
+def load_welcome_template_fixture(fixture_path) -> bool:
+    """Load welcome email template from a JSON fixture."""
+    try:
+        with open(fixture_path) as f:
+            for deserialized in serializers.deserialize('json', f):
+                if deserialized.object.name == settings.TEMPLATE_WELCOME_EMAIL_NAME:
+                    deserialized.save()
+                    logger.warning('Welcome email template \'%s\' loaded', deserialized.object.name)
+                    return True
+
+            return False
+
+    except FileNotFoundError:
+        logger.warning('Email template fixture not found.')
+        return False
+
+
+def send_welcome_email(sender, instance, **kwargs):
+    from post_office import models
+
+    try:
+        instance.send_welcome_email()
+
+    except models.EmailTemplate.DoesNotExist:
+        logger.warning('Welcome email template \'%s\' not found - attempting to load from fixtures',
+                       settings.TEMPLATE_WELCOME_EMAIL_NAME)
+        
+        is_loaded = False
+        if settings.CUSTOMISATION_NAME:
+            # Customisation app present - try here first
+            is_loaded |= load_welcome_template_fixture(
+                settings.BASE_DIR.joinpath('custom', 'fixtures', 'email_templates.json')
+            )
+
+        # |= operator shortcuts - only try here if we don't already have it
+        is_loaded |= load_welcome_template_fixture(
+            settings.BASE_DIR.joinpath('people', 'fixtures', 'email_templates.json')
+        )
+
+        if is_loaded:
+            instance.send_welcome_email()
+
+        else:
+            logger.error('Welcome email template \'%s\' not found', settings.TEMPLATE_WELCOME_EMAIL_NAME)
 
 
 class PeopleConfig(AppConfig):
     name = 'people'
+    
+    def ready(self) -> None:
+        # Activate signal handlers
+        post_save.connect(send_welcome_email,
+                          sender='people.user')

people/fixtures/email_templates.json

@@ -0,0 +1,16 @@
+[
+    {
+        "model": "post_office.emailtemplate",
+        "fields": {
+            "name": "welcome-email",
+            "description": "Default welcome email template",
+            "created": "2020-04-27T12:13:30.448Z",
+            "last_updated": "2020-04-27T14:45:27.152Z",
+            "subject": "Welcome to {{settings.PROJECT_LONG_NAME}}",
+            "content": "Dear {{ user.get_full_name }},\r\n\r\nWelcome to {{ settings.PROJECT_LONG_NAME }}.\r\n\r\nThanks,\r\n\r\nThe {{ settings.PROJECT_LONG_NAME }} team",
+            "html_content": "<h1>{{ settings.PROJECT_LONG_NAME }}</h1>\r\n\r\nDear {{ user.get_full_name }},\r\n\r\nWelcome to {{ settings.PROJECT_LONG_NAME }}.\r\n\r\nThanks,\r\n\r\nThe {{ settings.PROJECT_LONG_NAME }} team",
+            "language": "",
+            "default_template": null
+        }
+    }
+]

people/models/person.py

@@ -5,6 +5,8 @@ from django.urls import reverse
 from django.utils.translation import gettext_lazy as _
 
 from django_countries.fields import CountryField
+from django_settings_export import settings_export
+from post_office import mail
 
 from backports.db.models.enums import TextChoices
 
@@ -28,6 +30,22 @@ class User(AbstractUser):
         """
         return hasattr(self, 'person')
 
+    def send_welcome_email(self):
+        """Send a welcome email to a new user."""
+        # Get exported data from settings.py first
+        context = settings_export(None)
+        context.update({
+            'user': self,
+        })
+        
+        mail.send(
+            [self.email],
+            sender=settings.DEFAULT_FROM_EMAIL,
+            template=settings.TEMPLATE_WELCOME_EMAIL_NAME,
+            context=context,
+            priority='now'  # Send immediately - don't add to queue
+        )
+
 
 class Organisation(models.Model):
     """

requirements.txt

@@ -9,11 +9,13 @@ django-countries==5.5
 django-dbbackup==3.2.0
 django-filter==2.2.0
 django-picklefield==2.1.1
+django-post-office==3.4.0
 django-select2==7.2.0
 django-settings-export==1.2.1
 djangorestframework==3.11.0
 dodgy==0.2.1
 isort==4.3.21
+jsonfield==3.1.0
 lazy-object-proxy==1.4.3
 mccabe==0.6.1
 mysqlclient==1.4.6