Custom template filters in Django - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a custom template filter in Django?

A custom template filter is a user-defined function that processes data in Django templates to change how values are displayed. It lets you create your own way to modify or format data inside templates.

beginner

How do you register a custom template filter in Django?

You create a Python function and register it with Django's template library using the @register.filter decorator inside a file in the 'templatetags' folder. This makes the filter available in templates.

intermediate

Where should you place your custom template filter code in a Django project?

Inside a 'templatetags' folder within a Django app. This folder must contain an __init__.py file to be recognized as a module.

beginner

What is the purpose of the @register.filter decorator in Django custom filters?

It tells Django that the function below it is a template filter and makes it available to use inside templates.

intermediate

Can custom template filters accept arguments? How?

Yes, custom filters can accept extra arguments by defining them in the function parameters after the value. You can pass these arguments in the template using a colon, like {{ value|filtername:arg }}.

Where do you put custom template filters in a Django app?

A In the static files folder

B Inside a 'templatetags' folder with __init__.py

C Directly inside views.py

D In the main project folder

Custom template filters must be placed inside a 'templatetags' folder within a Django app, which must have an __init__.py file.

How do you make Django recognize a function as a template filter?

A Use @register.filter decorator

B Name the function 'filter'

C Import it in settings.py

D Add it to urls.py

The @register.filter decorator registers the function as a template filter in Django.

What does a custom template filter do?

A Modifies or formats data in templates

B Handles HTTP requests

C Defines database models

D Manages user authentication

Custom template filters change how data is displayed in templates by modifying or formatting it.

How do you pass an argument to a custom template filter in a template?

A {{ filtername(value, argument) }}

B {{ value|filtername(argument) }}

C {% filter filtername argument %}

D {{ value|filtername:argument }}

Arguments are passed to filters in templates using a colon, like {{ value|filtername:argument }}.

What file must exist inside the 'templatetags' folder for Django to recognize it?

A views.py

B filters.py

C __init__.py

D models.py

The __init__.py file makes the 'templatetags' folder a Python module so Django can load filters from it.

Explain how to create and use a custom template filter in Django from start to finish.

Think about folder structure, function, registration, loading, and usage.

Describe how to pass an argument to a custom template filter and how to handle it in the filter function.

Focus on function parameters and template syntax.