The MailFactory Interface

In daily work email branding is important because it will call your customer to action.

MailFactory comes with a little tool that helps you to test your emails.

To do that, we generate a Django Form so that you may provide a context for your email.

Here’s how you can customize your administration form.

Enabling MailFactory administration

You just need to enable the urls:

project/urls.py:

urlpatterns = (
    # ...
    url(r'^admin/mails/', include('mail_factory.urls')),
    url(r'^admin/', include(admin.site.urls)),
    # ...
)

Then you can connect to /admin/mails/ to try out your emails.

Registering a specific form

These two calls are equivalent:

from mail_factory import factory, BaseMail


class InvitationMail(BaseMail):
    template_name = "invitation"
    params = ['user']

factory.register(InvitationMail)

from mail_factory import factory, MailForm, BaseMail


class InvitationMail(BaseMail):
    template_name = "invitation"
    params = ['user']

factory.register(InvitationMail, MailForm)

Creating a custom MailForm

We may also want to build a very specific form for our email.

Let’s say we have a share this page email, with a custom message:

from mail_factory import factory, BaseMail, MailForm


class SharePageMail(BaseMail):
    template_name = "share_page"
    params = ['user', 'message', 'date']


class SharePageMailForm(MailForm):
    user = forms.ModelChoiceField(queryset=User.objects.all())
    message = forms.CharField(widget=forms.Textarea)
    date = forms.DateTimeField()


factory.register(SharePageMail, SharePageMailForm)

Define form initial data

You can define Meta.initial to automatically provide a context for your mail.

import datetime
import uuid

from django.conf import settings
from django.core.urlresolvers import reverse_lazy as reverse
from django import forms
from mail_factory import factory, MailForm, BaseMail


class ShareBucketMail(BaseMail):
    template_name = 'share_bucket'
    params = ['first_name', 'last_name', 'comment', 'expiration_date',
              'activation_url']


def activation_url():
    return '%s%s' % (
        settings.SITE_URL, reverse('share:index',
                                   args=[str(uuid.uuid4()).replace('-', '')]))


class ShareBucketForm(MailForm):
    expiration_date = forms.DateField()

    class Meta:
        initial = {'first_name': 'Thibaut',
                   'last_name': 'Dupont',
                   'comment': 'I shared with you documents we talked about.',
                   'expiration_date': datetime.date.today,
                   'activation_url': activation_url}

factory.register(ShareBucketMail, ShareBucketForm)

Then the mail form will be autopopulated with this data.

Creating your application custom MailForm

By default, all email params are represented as a forms.CharField(), which uses a basic text input.

Let’s create a project wide BaseMailForm that uses a ModelChoiceField on auth.models.User each time a user param is needed in the email.

from django.contrib.auth.models import User
from django import forms
from mail_factory.forms import MailForm


class BaseMailForm(MailForm):
    def get_field_for_param(self, param):
        if param == 'user':
            return forms.ModelChoiceField(
                queryset=User.objects.order_by('last_name', 'first_name'))

        return super(BaseMailForm, self).get_field_for_param(param)

Now you need to inherit from this BaseMailForm to make use of it for your custom mail forms:

class MyCustomMailForm(BaseMailForm):
    # your own customizations here

If you want this BaseMailForm to be used automatically when registering a mail with no custom form, here’s how to do it:

from mail_factory import MailFactory


class BaseMailFactory(MailFactory):
    mail_form = BaseMailForm
factory = BaseMailFactory

And use this new factory everywhere in your code instead of mail_factory.factory.

Previewing your email

Sometimes however, you don’t need or want to render the email, having to provide some real data (eg a user, a site, some complex model…).

The emails may be written by your sales or marketing team, set up by your designer, and all of those don’t want to cope with the setting up of real data.

All they want is to be able to preview the email, in the different languages available.

This is where email previewing is useful.

Previewing is available straight away thanks to sane defaults. It uses the data returned by get_preview_data to add (possibly) non valid data to the context used to preview the mail.

This data will override any data that was returned by get_context_data, which in turn uses the form’s Meta.initial, and in last resort, returns “###”.

The preview can thus use fake data: let’s take the second example from this page, the SharePageMail:

import datetime

from django.contrib.auth.models import User
from django.conf import settings

from mail_factory import factory, MailForm


class SharePageMailForm(MailForm):
    user = forms.ModelChoiceField(queryset=User.objects.all())
    message = forms.CharField(widget=forms.Textarea)
    date = forms.DateTimeField()

    class Meta:
        initial = {'message': 'Some message'}

    def get_preview_data(self, **kwargs):
        data = super(SharePageMailForm, self).get_preview_data(**kwargs)
        data['date'] = datetime.date.today()
        # create on-the-fly fake User, not saved in database: not valid data
        # but still added to context for previewing
        data['user'] = User(first_name='John', last_name='Doe')
        return data

factory.register(SharePageMail, SharePageMailForm)

With this feature, when displaying the mail form in the admin (to render the email with real data), the email will also be previewed in the different available languages with the fake data provided by the form’s get_preview_data, which overrides the data returned by get_context_data.