The document discusses transitioning a website with 80 HTML template files and over 4,000 lines of code from Django templates to Jinja2 templates. The plan was to deploy a Django/Jinja2 compatible subset and add a feature flag to toggle between the template pipelines. Some examples discussed include replacing the {% csrf_token %} tag with HTML, handling undefined context variables, and moving Python code and template code between templates and Python files. The document also asks how readers can help by trying out the company's GitHub repos.

1. A Two-step Dance with
Django and Jinja2
Templates
Sebastien Mirolo
@seabasscapoeira
smirolo@djaodjin.com

2. Motivation

3. Where we started
- 80 template files
- 4.3K lines of HTML template code
+ Customers relying
on site to process payments

4. The Plan
Deploy Django /
Jinja2 compatible
subset
Feature flag to
toggle between
template pipelines

5. An Easy Bit
{% csrf_token %}
-{% csrf_token %}
+<input type="hidden" name=“csrfmiddlewaretoken"
value="{{csrf_token}}">

6. The Good Old Times
$ cat base.html
{% block bodyscripts %}
<script type="text/javascript" charset="utf-8"
src=“/assets/base.js"></script>
{% block base_bodyscripts %}{% endblock %}
{% endblock %}
$ cat index.html
{% extends "base.html" %}
{% block bodyscripts %}
{% block base_bodyscripts %}
{{ block.super }}
<script type="text/javascript" charset="utf-8"
src="/assets/index.js"></script>

7. Undefined Context
Variables
{% if urls.profile %}
<a href="{{urls.profile}}">My Profile</a>
{% endif %}

8. When everything can
be solved with a filter
$ cat
templatetags/authenticated_tags.py
...
@register.filter()
def is_authenticated(request):
return hasattr(request, 'user') and
request.user.is_authenticated()
$ cat index.html
{% if request.user|is_authenticated %}
...
{% endif %}
is_authenticated
vs.
is_authenticated(
)
capfirst
vs.
capitalize

9. Moving Python code
into Templates
• crispy
• {% include with %} vs. {% macro
%}

10. Moving Template
code into Python
• URL patterns
• {% if forloop.counter0|divisible_by:3 %} vs. {% if
loop.index is divisibleby 3 %}

11. Jinja2 rendering
pipeline quirks
• Template loaders
• Cache dimensioning
• Optimizer in a multi-tier context

12. How you can help?
• Clone DjaoDjin repos and try them
out!
• Star us on GitHub!
https://github.com/djaodjin/djaodjin-pages/
https://github.com/djaodjin/djaodjin-saas/

13. Thank You
Sebastien Mirolo
@seabasscapoeira
smirolo@djaodjin.com