How to get object from PK inside Django template?

Question

Inside django template, I would like to get object's name using object's pk. For instance, given that I have pk of object from class A, I would like to do something like the following:

{{ A.objects.get(pk=A_pk).name }}

How can I do this?

Answer 1

From the docs on The Django Template Language:

Accessing method calls:

Because Django intentionally limits the amount of logic processing available in the template language, it is not possible to pass arguments to method calls accessed from within templates. Data should be calculated in views, then passed to templates for display.

So you see, you should be calculating this in your views.py:

def my_view(request, A_pk):
    ...     
    a = A.objects.get(pk=A_pk)    
    ...
    return render_to_response('myapp/mytemplate.html', {'a': a})

And in your template:

{{ a.name }}
{{ a.some_field }}
{{ a.some_other_field }}

Answer 2

You can add your own tag if you want to. Like this:

from django import template
register = template.Library()

@register.simple_tag
def get_obj(pk, attr):
    obj = getattr(A.objects.get(pk=int(pk)), attr)
    return obj

Then load tag in your template

{% load get_obj from your_module %}

and use it

{% get_obj "A_pk" "name" %}