Call functions out of jinja2 templates

I do a few webprojects with Flask and I love it! While creating a template i searched for a way to call functions from within the template, and found out that i can use a @app.context_processor decorator.

def my_utility_processor():

    def date_now(format="%d.m.%Y %H:%M:%S"):
        """ returns the formated datetime """

    def foo():
        """ returns bulshit """
        return "bar bar bar"

    return dict(date_now=date_now, baz=foo)

In the jinja2 template you can now simply call the functions like this:

{% raw %}

{% for n in news %}
    Give me some {{ baz() }}!
{% endfor %}

Copyright by me 2005 - {{ date_now("%Y") }}

{% endraw %}

Lets assume news contains 2 elements, the result looks like this:

Give me some bar bar bar!

Give me some bar bar bar!

Copyright by me 2005 - 2013

The important part is return dict(date_now=date_now, baz=foo). The first word is the key, the value is a function pointer. The key is the keyword you write in your template code {% raw %}{{ baz() }} for example, foo is the name of the function that get called.