OSIS Mail Template

OSIS Mail Template is a Django application to manage mail templates across OSIS platform.

Requirements

OSIS Mail Template requires:

• Django 2.2+
• django-ckeditor 5+
• html2text
• django-bootstrap3
• django-autocomplete-light 3.5.1+

How to install ?

For production

# From your osis install, with python environment activated
pip install git+https://github.com/uclouvain/osis-mail-template.git@dev#egg=osis_mail_template

For development

# From your osis install, with python environment activated
git clone [email protected]:uclouvain/osis-mail-template.git
pip install -e ./osis-mail-template

Configuring Django

Add osis_mail_template to INSTALLED_APPS:

INSTALLED_APPS = (
    ...
    'osis_mail_template',
    ...
)

Using OSIS Mail Template

osis_mail_template is based on the idea that you register mail templates within a Django application. Each mail template subject and content will then be configurable through a common interface. An email template consists of an identifier and a list of token, each token maps a name with a description, and an example value.

Declaring a mail template

To declare a mail template within a Django application:

• Create a package, called mail_templates, at the root of the app :

 <app_name>
 | api
     |__ #...
 | #...
 | mail_templates.py

• Register as many mail templates as you want, it is advised to use constants for mail template identifiers to prevent mismatching, and specify a tag to find easily the mail in administration.

from django.utils.translation import gettext_lazy as _
from osis_mail_template import templates, Token

OSIS_ADMISSION_MAIL_CREATE = 'osis-admission-creation'
templates.register(
    OSIS_ADMISSION_MAIL_CREATE,
    description=_("A short description about the mail template and when it is sent"),
    tokens=[
      Token(
          name='person_first_name',
          description=_("The first name of the person concerned by the admission"),
          example="John",
      ),
      Token(
        'person_last_name',
        _("The last name of the person concerned by the admission"),
        "Doe",
      ),
    ],
    tag='Admission',
)

• To prevent mail which templates have not been configured, it is strongly recommended creating a migration to initialize the content of a newly registered mail template:

from django.db import migrations
from osis_mail_template import MailTemplateMigration

from myapp.mail_templates import MY_TEMPLATE_IDENTIFIER

subjects = {
  'en': '[OSIS] A dummy subject',
  'fr-be': '[OSIS] Un sujet bidon'
}
contents = {
  'en': '''<p>Hello {first_name} {last_name},</p>

<p>This is the mail template to notify you about {reason}.</p>

<p>---<br/>
The OSIS Team</p>
''',
  'fr-be': '''<p>Bonjour {first_name} {last_name},</p>

<p>Ceci est un template d'email à propos de {reason}.</p>

<p>---<br/>
L'équipe OSIS</p>
''',
}


class Migration(migrations.Migration):
    dependencies = [
        ('osis_mail_template', '0001_initial'),
        ...
    ]

    operations = [
        MailTemplateMigration(MY_TEMPLATE_IDENTIFIER, subjects, contents)
    ]

Configuring mail templates

As soon as a mail template is declared, it can be configured for both French and English in the administration.

A list of all mail template is available for users who have the permission osis_mail_template.configure, with the option to configure or preview a mail template :

• when configuring, 2 forms (one for each language) with the list of tokens will be made available.
• when previewing, the mail template will be rendered with example values from the tokens

If a mail template is registered twice with same identifier, a DuplicateMailTemplateIdentifier exception will be thrown.

Rendering a mail template

Upon an action of its choosing, the calling module can render a mail template with the function generate_email(mail_template_id, language, tokens, recipients, sender) . It will return an EmailMessage object ready to be sent through.

The following parameters are expected:

• mail_template_id is the mail template identifier as declared somewhere in a mail_templates.py file, will raise an UnknownMailTemplateIdentifier exception if the mail template does not exist
• tokens is a dictionary mapping token names to their value. Keys must reference all tokens declared, if any is missing, it will display as TOKEN_name_UNDEFINED. Values must be castable as string, if not, it will raise a TypeError
• recipients is a list of email as strings to send the email to
• language is a language identifier from settings.LANGUAGES, will raise an UnknownLanguage exception if the language does not exist
• sender is the e-mail for the sender, if not specified, will default to settings.DEFAULT_FROM_EMAIL

If the configured email template is not yet configured (has no content), an EmptyMailTemplateContent exception will be thrown.

Overriding the HTML email base template

The HTML configured through the editor is, at rendering, injected into a base template located at osis_mail_template/base_email.html in which the content is located inside the content variable.

For the plain text alternative, the HTML content is passed through the html2text function configured will the following parameters:

• LINKS_EACH_PARAGRAPH = True for putting links after every paragraph
• BODY_WIDTH = 120 for wrapping long lines
• INLINE_LINKS = False to put links at the end of the text
• WRAP_LINKS = False to prevent link wrapping
• WRAP_LIST_ITEMS = True to allow list item wrapping
• USE_AUTOMATIC_LINKS = True to simplify self-targeted links

Getting only the rendered content

It may be useful to get only the content of the subject and body of a mail message, prior to sending it, so that the user can modify the contents. OSIS Mail template allows that by providing a render_email_content(mail_template_id, language, tokens) function, which returns a tuple of subject and content.

This can be later used in a form for sending customized content by the user.

Getting a selector of mail templates

It may be useful to offer the front-end user the possibility to select the mail template. OSIS Mail template allows that by providing autocomplete views, usable with a ListSelect2 widget from django-autocomplete-light.

from  django import forms
from dal import autocomplete, forward

class MailTemplateConfigureForm(forms.Form):
    # Example for autocompleting on all templates
    template = forms.CharField(
        widget=autocomplete.ListSelect2(url="osis_mail_template:autocomplete")
    )
    # Example for autocompleting on templates for a selected tag
    template_filtered_by_tag = forms.CharField(
        widget=autocomplete.ListSelect2(
          url="osis_mail_template:autocomplete",
          forward=(forward.Const('tag', 'Admission'),)
        )
    )

This can be later used in the form for sending customized content by the user.