005 Inbuilt and Custom Template Tag Filter in Django

Inbuilt and Custom Template Tag Filter in Django

Inbuilt Filter

• One can use in-built filters directly
• See an example of in-built filters below. data.number is passed from view and 99 is added to the passed value before displaying

index.html

<!DOCTYPE html>{% extends "mainApp/base.html" %}
    {% block body_block %}
        <div class="container">
            <div class="jumbotron">
                <h1>Welcome to a project about users</h1>
                <h2>{{ data.number|add:"99" }}</h2>
            </div>
        </div>
    {% endblock %}

Custom Filter

• To create a custom filter as per your unique needs follow this process:
• Inside app folder, create a folder named templatetags
• Inside templatetags create a blank file named __init__.py. This tells python that templatetags is a package
• Create another file named my_extras.py. This is where custom filters will be coded
• The following example will show how to remove the word "World" from a string.

index.html

<!DOCTYPE html>{% extends "mainApp/base.html" %}
    {% block body_block %}
        <div class="container">
            <div class="jumbotron">
                <h1>Welcome to a project about users</h1>
                <h2>{{ data.text|cut:"World" }}</h2>
            </div>
        </div>
    {% endblock %}

• And the function will be written in app > templatetags > my_extras.py

# Create Own Template Filter
from django import template

register = template.Library()


@register.filter(name='cut')
def cutout(value, arg):
    """    This cuts out all the values of 'arg' from the string!    :param value:    :param arg:    :return:    """    return value.replace(arg, '')

# register.filter('cut', cutout)

• And that's how we do it