Pass variables from child template to parent in Jinja2

Question

I want to have one parent template and many children templates with their own variables that they pass to the parent, like so:

parent.html:

{% block          


        

Answer 1

If Nathron's solution does not fix your problem, you can use a function in combination with a global python variable to pass a variable value.

• Advantage: The variable's value will available in all templates. You can set the variable inside a block.
• Disadvantage: More overhead.

This is what I did:

child.j2:

{{ set_my_var('new var value') }}

base.j2

{% set my_var = get_my_var() %}

python code

my_var = ''


def set_my_var(value):
    global my_var 
    my_var = value
    return '' # a function returning nothing will print a "none"


def get_my_var():
    global my_var 
    return my_var 

# make functions available inside jinja2
config = { 'set_my_var': set_my_var,
           'get_my_var': get_my_var,
           ...
         }

template = env.get_template('base.j2')

generated_code = template.render(config)

Answer 2

Ah. Apparently they won't be defined when they are passed through blocks. The solution is to just remove the block tags and set it up like so:

parent.html:

{% if bool_var %}
    {{ option_a }}
{% else %}
    {{ option_b }}
{% endif %}

child.html:

{% extends "parent.html" %}

{% set bool_var = True %}
{% set option_a = 'Text specific to this child template' %}
{% set option_b = 'More text specific to this child template' %}