django-quick-context

A django app for quickly setting global context variables on all templates.

It also allows fetching model instances from the database directly in the templates, which can be very useful in certain cases such as when the views are controlled by a third party app. See Example 3 for more.

Installation

pip install django-quick-context

Then add 'quick_context.context_processors.quick' to your context_processors:

# settings.py

TEMPLATES = [
    {
        # ...
        'OPTIONS': {
            'context_processors': [
                # ...
                'quick_context.context_processors.quick',
            ],
        },
    },
]

Usage

Example 1

Since version 1.4, this app allows you to access your Django project's settings effortlessly.

So, in your templates you can do this to access the settings:

{{ quick.settings.SOME_VARIABLE }}

Example 2

Let's say you want to make a variable called currency available in all templates. Put this code in a file where it gets loaded on startup (such as project's or app's __init__.py or apps.py file).

from quick_context import ContextRegistry

ContextRegistry.register(name='currency', value='USD')

The quick_context app makes a variable called quick available to every template. Every variable that you register with the ContextRegistry, it will be available as an attribute of the quick variable.

So, you can access the currency variable in the templates like this:

{{ quick.currency }}

Example 3

This is a more useful case for using quick_context.

Suppose you have a Notice model which allows you to display different notices on different pages in your website. For example, 'Home' page has a different notice and 'Contact' page has a different notice.

A sample Notice model:

# models.py

class Notice(models.Model):
    name = models.CharField(unique=True)
    message = models.CharField()

# Let's create a few notices
Notice.objects.create(name='homepage_notice', message='...')
Notice.objects.create(name='contact_notice', message='...')
Notice.objects.create(name='about_notice', message='...')

Now, to include a notice in the template, you'll have to send it the template context from the view:

# views.py

def home_view(request):
    notice = Notice.objects.get(name='homepage_notice')
    context = {'notice': notice}

    return ...

def contact_view(request):
    # ... same as above ...

# repeat for other view ...

As you can see, this process is repetitve.

quick_context provides a better way to do it.

First, register the Notice model:

# models.py

from quick_context import ContextRegistry

class Notice(...):
    ...

ContextRegistry.register_model(name='notice', model=Notice, lookup_field='name')

Now, you can access a notice for a particular page without having to pass it from the views:

{{ quick.notice.homepage_notice.message }} -> displays message of "homepage_notice"

{{ quick.notice.contact_notice.message }} -> displays message of "contact_notice"

The lookup_field must be a field which has unique=True. This is important because behind the scenes, quick_context just does a Model.objects.get(...) lookup and get expects a single result from the database. If there are more than one results, Django will throw a MultipleObjectsReturned exception.

Fetching multiple objects and filtering queryset

Since version 1.2, support for basic filtering has been added.

You can fetch multiple objects by applying a filter on the lookup field:

{% for notice in quick.notice.filter__icontains.homepage %}
     {{ notice.message }}
{% endfor %}

The above is equivalent to:

Notice.objects.filter(name__icontains='homepage')

API

ContextRegistry.register(cls, name, value)

Register a global context variable.

name: (string) Name of the variable.
value: (any) A value for the variable. It can be anything: a string, a class, dictionary, etc.

ContextRegistry.register_model(cls, name, model, lookup_field)

Register a model.

name: (string) Name of the variable.
model: (class) The model class.
lookup_field: (string) Name of the field to use for the lookup. Ensure that this field has unique=True because quick_context just does a Model.objects.get(...) lookup and get expects a single result from the database. If there are more than one results, Django will throw a MultipleObjectsReturned exception.

ContextRegistry.update(cls, name, value)

Updates the value of an already registered variable.

name: (string) Name of the variable.
value: (any) New value for the variable.

ContextRegistry.get_registry(cls)

Returns a list of all the registered variables.

License

BSD-3-Clause