how to create a reusable function available across apps in django - django

Question

I have the following function that I call in all of my apps and in almost every view function.
def get_customer(request):
return request.user.customer
I want to have one function that I can call from every app or even have this value available in every view.
How can I do this?

Answer 1

I am not really sure how you want to use, but if you need something reusable mostly for templates (as views handle logic differently depending on the request) then you can proceed with the bellow method, if you need something reusable in different parts of the stack, then a simple function / class that is imported in the appropriate parts is just enough.
If you want to inject a reusable var inside the view, then a context.processor is the good place to have this kind of logic.
create a context_processors.py file (name does not matter, but it's always nice to follow Django naming schemes for readability) in one of your apps (most likely the app that deals mostly with the logic, probably the customer app).
In your context_processors.py:
def get_customer(request):
try:
customer = request.user.customer
return {'customer': customer}
except:
"""
You need to always return a dictionary, even empty.
"""
return {}
Enable the context processor, in your TEMPLATE_CONTEXT_PROCESSORS (settings.py):
TEMPLATE_CONTEXT_PROCESSORS = (
"django.contry.context_processors.request",
"django.contrib.auth.context_processors.auth",
"django.core.context_processors.debug",
"django.core.context_processors.i18n",
"django.core.context_processors.media",
"django.core.context_processors.static",
"django.core.context_processors.tz",
"django.contrib.messages.context_processors.messages"
"yourapp.context_processors.get_customer"
)
THen in your template you can access this:
{% if customer %}
...
{% endif %}
Mind though that is wise to create names that wont conflict with other parts, so it would be better to name the passed element
to something more unique like myappscustomer.
If you are using CBV's (Class Based Views) you could create a Mixin and reuse it:
class MyCustomerMixin(object):
def get_context_data(self, **kwargs):
context = super(MyCustomerMixin, self).get_context_data(**kwargs)
if self.request.user:
try:
context['mycustomer'] = self.request.user.customer
except:
pass
return context
Then use it in your View:
class SomeView(MyCustomerMixin, TemplateView):
....