Custom jinja filters - JINJA2_FILTERS

[Kani999]

Hello,

I'm trying to use JINJA2_FILTERS.

I've created:
configuration.py

...
# JINJA2_FILTERS
def to_czech_crown(number):
    if number:
        return '{:,}'.format(number).replace(',', ' ') + " Kč"
    else:
        return '---'

JINJA2_FILTERS = {'to_czech_crown': to_czech_crown}
...

Now I want to use the filter in my plugin:
invoices.html

   <td>{{ invoice.price|to_czech_crown }}</td>

But error occurs:

I found out, that the render method in my template_content.py:

        return self.render(
            'inventory_monitor/invoices_include.html',
            extra_context={
                'object': object,
                'invoices': invoices,
            }
        )

does not call the render_jinja2 method at utilities/utils.py:

def render_jinja2(template_code, context):
    """
    Render a Jinja2 template with the provided context. Return the rendered content.
    """
    import ipdb; ipdb.set_trace()

    
    environment = SandboxedEnvironment()
    environment.filters.update(get_config().JINJA2_FILTERS)
    
    
    return environment.from_string(source=template_code).render(**context)

How can I add custom jinja filter to be in use in template_content rendering?

---

Edit:

In the settings, I can see my custom filter:

import netbox.settings as netbox_settings
netbox_settings.JINJA2_FILTERS
>>> {'to_czech_crown': <function to_czech_crown at 0x7fa98cf1f010>}

[Kani999]

Adding:

@register.filter()
def to_czech_crown(number):
    if number:
        return '{:,}'.format(number).replace(',', ' ') + " Kč"
    else:
        return '---'

To netbox/utilities/templatetags/builtins/filters.py works, but I don't want to add the function to the netbox core.

[Kani999]

Adding to my plugin views.py:

from utilities.templatetags.builtins.filters import register

@register.filter()
def to_czech_crown(number):
    if number:
        return '{:,}'.format(number).replace(',', ' ') + " Kč"
    else:
        return '---'

solves the problem. But I don't think this is the best way.

[kkthxbye-code]

The feature is intended to register filters for user created templates, like webhook body template, export templates and custom links. These places use jinja2 as a template engine. The normal templates and templates used in plugins use the django templating engine and you should register templatetags for these yourself in your plugin.

[Kani999]

Okay thank you. I did not found this info in the docs.

[Kani999]

@kkthxbye-code answer

The feature is intended to register filters for user created templates, like webhook body template, export templates and custom links. These places use jinja2 as a template engine. The normal templates and templates used in plugins use the django templating engine and you should register templatetags for these yourself in your plugin.

[zhabchenko]

Hi!
i adding my custom filter in netbox/utilities/templatetags/builtins/filters.py, but but it still won't load, and even standard filters from this repository do not work.

[kkthxbye-code]

Modifying the core netbox code without understanding it, and adding a django template filter instead of a jinja2 filter will obviously not work. Please follow the documentation:

https://docs.netbox.dev/en/stable/configuration/system/#jinja2_filters

[zhabchenko]

Yes, it's worked. Thanks!