Mail Views

Rendering and sending emails in Django can quickly become repetitive and error-prone. By encapsulating message rendering within view classes, you can easily compose messages in a structured and clear manner.

The idea behind the method is identhical to the template class based view: you can select the template to use, in our case one for the subject and one for the body (and one extra for the html), you can pass the data you need overriding the get_context_data method and the message rendering is made in render_to_message where you can also customize the parameters as sender, cc, cco, etc. or delay the decision to the send method.

Managing mails could become a crazy thing quite fast, so the idea is to be able to organize the mail templates in folders and use the mailview classes to provide them with the data you need.

Using inheritance in templates, mixins and inheritance will give you again the control.

Your first email

Let’s suppose we want to send a notificantion message to a mailing list. We don’t have a customized email, but we want to be able to render the e-mail

import datetime
from django_yubin.message_views import TemplatedEmailMessageView

class NewsletterView(TemplatedEmailMessageView):
    subject_template_name = 'emails/newsletter/subject.txt'
    body_template_name = 'emails/newsletter/body.txt'

    def get_context_data(self, **kwargs):
        """
        here we can get the addtional data we want
        """
        context = super().get_context_data(**kwargs)
        context['day'] = datetime.date.today()
        return context

# Instantiate and send a message.
NewsletterView().send(to=('mynewsletter@example.com', ))

This would render and send a message to the newsletter with the DEFAULT_FROM_EMAIL emails settings. Sometimes we’d like to send it with different e-mail, so we can customize it as

NewsletterView().send(from_email='no-reply@example.com',
                      to=('mynewsletter@exemple.com', ))

Any keywords you pass in send will be forwarded to the django mail calss, so you can use the same parameters you have in the Django EmailMessage class documentation:

  • from_email: The sender’s address. Both fred@example.com and Fred <fred@example.com> forms are legal. If omitted, the DEFAULT_FROM_EMAIL setting is used.

  • to: A list or tuple of recipient addresses.

  • bcc: A list or tuple of addresses used in the “Bcc” header when sending the email.

  • cc: A list or tuple of recipient addresses used in the “Cc” header when sending the email.

Instead of using send you can use render_to_message method. Its parameters are the same as the send method, but instead of sending the e-mail it will return you an instance of EmailMessage that you can use to customize the e-mail before sending it.

In our example, we could write:

import datetime
from django_yubin.message_views import TemplatedEmailMessageView

class NewsletterView(TemplatedEmailMessageView):
    subject_template_name = 'emails/newsletter/subject.txt'
    body_template_name = 'emails/newsletter/body.txt'

    def render_to_message(self, extra_context=None, **kwargs):
        kwargs['to'] = ('mynewsletter@example.com',)
        kwargs['from_email'] = 'no-reply@example.com'
        return super().render_to_message(extra_context, **kwargs)

    def get_context_data(self, **kwargs):
        """
        here we can get the addtional data we want
        """
        context = super().get_context_data(**kwargs)
        context['day'] = datetime.date.today()
        return context

# Instantiate and send a message.
NewsletterView().send()

Supose now that we wan’t to send a second newsletter, the monthly one for example, then we could just write

class MonthlyNewsletterView(NewsletterView):
    subject_template_name = 'emails/newsletter/monthly_subject.txt'
    body_template_name = 'emails/newsletter/monthly_body.txt'

MonthlyNewsletterView().send()

HTML emails

In the previous example we have sent just text emails. If we want to send HTML email we need also an additional template to render the HTML content. You just have to inherit your class from TemplatedHTMLEmailMessageView and write the template you’re going to use in html_body_template_name, so usually we’ll have something like

import datetime
from django_yubin.message_views import TemplatedHTMLEmailMessageView

class NewsletterView(TemplatedHTMLEmailMessageView):
    subject_template_name = 'emails/newsletter/subject.txt'
    body_template_name = 'emails/newsletter/body.txt'
    html_body_template_name = 'emails/newsletter/body_html.html'

    def render_to_message(self, extra_context=None, **kwargs):
        kwargs['to'] = ('mynewsletter@example.com',)
        kwargs['from_email'] = 'no-reply@example.com'
        return super().render_to_message(extra_context=None, **kwargs)

    def get_context_data(self, **kwargs):
        """
        here we can get the addtional data we want
        """
        context = super().get_context_data(**kwargs)
        context['day'] = datetime.date.today()
        return context

# Instantiate and send a message.
NewsletterView().send()

Usually, in HTML emails you need to link files from your site. MEDIA_URL and STATIC_URL variables are available in the template context. These variables are full urls so you need to have django.contrib.sites and SITE_ID properly set in your SETTINGS.py.

Attachments

To add an attachment to your mail you have to remember that render_to_message returns a EmailMessage instance, so you can use https://docs.djangoproject.com/en/dev/topics/email/#emailmessage-objects.

As usually we send just an attachment, we have created a class for that just passing the file name or a file object: TemplatedAttachmentEmailMessageView. For example, if we want to send in our newsletter a pdf file we could do

import datetime
from django_yubin.message_views import TemplatedAttachmentEmailMessageView

class NewsletterView(TemplatedAttachmentEmailMessageView):
    subject_template_name = 'emails/newsletter/subject.txt'
    body_template_name = 'emails/newsletter/body.txt'
    html_body_template_name = 'emails/newsletter/body_html.html'

    def render_to_message(self, extra_context=None, **kwargs):
        kwargs['to'] = ('mynewsletter@example.com',)
        kwargs['from_email'] = 'no-reply@example.com'
        return super().render_to_message(extra_context=None, **kwargs)

    def get_context_data(self, **kwargs):
        """
        here we can get the addtional data we want
        """
        context = super().get_context_data(**kwargs)
        context['day'] = datetime.date.today()
        return context

# Instantiate and send a message.
attachment = os.path.join(OUR_ROOT_FILES_PATH, 'newsletter/attachment.pdf')
NewsletterView().send(attachment=attachment, mimetype="application/pdf")

As an attachment you must provide the full file path or the data stream.

Multiple attachments

Sending multiple attachments works the same way but using the class TemplatedMultipleAttachmentsEmailMessageView. Example:

import datetime
from django_yubin.message_views import TemplatedMultipleAttachmentsEmailMessageView

class NewsletterView(TemplatedMultipleAttachmentsEmailMessageView):
    subject_template_name = 'emails/newsletter/subject.txt'
    body_template_name = 'emails/newsletter/body.txt'
    html_body_template_name = 'emails/newsletter/body_html.html'

    def render_to_message(self, extra_context=None, **kwargs):
        kwargs['to'] = ('mynewsletter@example.com',)
        kwargs['from_email'] = 'no-reply@example.com'
        return super().render_to_message(extra_context=None, **kwargs)

    def get_context_data(self, **kwargs):
        """
        here we can get the addtional data we want
        """
        context = super().get_context_data(**kwargs)
        context['day'] = datetime.date.today()
        return context

# Instantiate and send a message.
attachments = [
    {"attachment": os.path.join(OUR_ROOT_FILES_PATH, 'newsletter/attachment.pdf'), "filename": "attachment.pdf"},
    {"attachment": os.path.join(OUR_ROOT_FILES_PATH, 'newsletter/attachment2.pdf'), "filename": "attachment2.pdf"},
    {"attachment": os.path.join(OUR_ROOT_FILES_PATH, 'newsletter/attachment3.pdf'), "filename": "attachment3.pdf"},
]
NewsletterView().send(attachments=attachments)

Email to a user

The send method can receive any extra context that you need to create your emails. Even it can be usefull as a quick shortcut, it’s not e good pattern

from django_yubin.message_views import TemplatedEmailMessageView

# Subclass the TemplatedEmailMessageView adding the templates you want to render.
class WelcomeMessageView(TemplatedEmailMessageView):
    subject_template_name = 'emails/welcome/subject.txt'
    body_template_name = 'emails/welcome/body.txt'

# Instantiate and send a message.
WelcomeMessageView().send(extra_context={'user': user}, to=(user.email, ))

A better approach is to subclass TemplatedEmailMessageView. Its constructor accepts all the paameters that you need to generate the context and send the message. Example:

from django_yubin.message_views import TemplatedEmailMessageView

class WelcomeMessageView(TemplatedEmailMessageView):
    subject_template_name = 'emails/welcome/subject.txt'
    body_template_name = 'emails/welcome/body.txt'

    def __init__(self, user, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.user = user

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['user'] = self.user
        return context

    def render_to_message(self, *args, **kwargs):
        assert 'to' not in kwargs  # this should only be sent to the user
        kwargs['to'] = (self.user.email, )
        return super().render_to_message(*args, **kwargs)

# Instantiate and send a message.
WelcomeMessageView(user).send()

In fact, you might find it helpful to encapsulate the above “message for a user” pattern into a mixin or subclass that provides a standard abstraction for all user-related emails.