Email Template Rendering with Jinja and Safe Evaluation in Odoo

✅ Overview

Odoo uses Jinja2 templating and safe evaluation context to dynamically render email content such as:

• Subject
• Body (HTML/text)
• Sender and recipient addresses

This allows emails to be personalized per record (e.g., customer name, product details) using secure and controlled access to model fields and functions.

🔧 Where Jinja Is Used

Jinja expressions are commonly used in:

Field	Used In
Subject	{{ object.name }}
Email Body (HTML)	<p>Hello {{ object.partner_id.name }}</p>
Sender Email	{{ user.email }}
Email To / CC	{{ object.user_id.email }}

📘 Basic Syntax of Jinja​

🔒 Safe Evaluation (safe_eval)

Odoo restricts evaluation context to safe variables and methods only, to avoid security risks (e.g., executing arbitrary Python).

📌 Variables Available in Templates

Variable	Meaning
object	Current record (e.g., sale.order)
user	Current user (record of res.users)
ctx	Current context
format_tz()	Format datetime with timezone
format_date()	Format date
format_amount()	Format currency

Example 1: Custom Email Body

<p>Hello {{ object.partner_id.name }},</p>

<p>Your order <strong>{{ object.name }}</strong> has been confirmed with a total of 

<strong>{{ format_amount(object.amount_total, object.currency_id) }}</strong>.</p>

<p>Thanks,<br/>{{ user.company_id.name }}</p>

Example 2: Subject with Condition

{{ 'New Quotation' if object.state == 'draft' else 'Confirmed Order' }}

Example 3: Dynamic From Address

{{ user.email }}

🛠 How Rendering Works in Python​

🚫 Common Mistakes

Issue	Cause
UndefinedError: 'object' is undefined	Template used outside proper record context
Jinja syntax error	Missing {% endif %}, wrong brackets
HTML not rendering properly	Wrong field used (body_text instead of body_html)

✅ Summary Table

Concept	Description
Jinja2	Templating engine for email templates
object	Refers to the current record
user	Current user (sender)
format_* funcs	Helper functions to format values securely
safe_eval	Limits evaluation to safe variables
render_template()	Programmatic rendering of templates

🧠 Best Practices

• Always use {{ }} for expressions and {% %} for control logic.
• Use helper functions like format_amount() and format_date() instead of raw Python.
• Avoid calling unsafe or complex methods directly inside the template.
• Test templates via the "Send Test Email" feature in Developer Mode.