Django1.4: How to use order_by in template?

Question

models.py

from django.db import models
from django.contrib.auth.models import User
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes import generic

class Note(models.Model):
    contents = models.TextField()
    writer = models.ForeignKey(User, to_field='username')
    date = models.DateTimeField(auto_now_add=True)

    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = generic.GenericForeignKey('content_type', 'object_id')


class Customer(models.Model):
    name = models.CharField(max_length=50,)
    notes = generic.GenericRelation(Note, null=True)

Above is my models.py.

I want to use 'order_by'(https://docs.djangoproject.com/en/dev/ref/models/querysets/#order-by)

And...

views.py

from django.views.generic import DetailView
from crm.models import *

class customerDetailView(DetailView):
    context_object_name = 'customerDetail'
    template_name = "customerDetail.html"
    allow_empty = True
    model = Customer
    slug_field = 'name'

My views.py use DetailView(https://docs.djangoproject.com/en/1.4/ref/class-based-views/#detailview).

And

customerDetail.html

<table class="table table-bordered" style="width: 100%;">
    <tr>
        <td>Note</td>
    </tr>
    {% for i in customerDetail.notes.all.order_by %}<!-- It's not working -->
        <tr>
            <th>({{ i.date }}) {{ i.contents }}[{{ i.writer }}]</th>
        </tr>
    {% endfor %}
</table>

I want to use order_by in template...

What should I do?

have you tried `queryset = Customer.objects.order_by()` in `customerDetailView`? — rxdazn, Feb 13 '13 at 14:47
Yeah, I tried `queryset = Customer.objects.order_by('note__date')` and `queryset = Customer.objects.order_by('note__date')`. But failed... — chobo, Feb 13 '13 at 15:02

score 13 · Answer 1 · answered Feb 13 '13 at 15:43

13

Check out the dictsort filter, it's pretty much what you're looking for I think.

answered Feb 13 '13 at 15:43

msc

3,780
1
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2

This is the easiest answer and it does work on querysets. – Corentin S. Nov 23 '15 at 14:45

score 8 · Accepted Answer · edited May 23 '17 at 12:02

8

The order_by needs at least one argument, and Django does not allow you to pass arguments to a function or method inside a template.

Some alternatives are:

Use Jinja2 template engine instead of Django's one (Jinja2 will let you pass arguments to methods and is said to perform better)
order the dataset in the view
use the "Meta:ordering" attribute to define a default ordering criteria for your models
write a custom filter so you can queryset|order_by:'somefield' (see this snippet)
as suggested by Michal, you can write a custom Manager with predefined methods for the orderings you need

edited May 23 '17 at 12:02

Community

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answered Feb 13 '13 at 14:52

Paulo Scardine

73,447
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...or use custom Manager for the class which will provide you predefined ways of ordering – Michal Čihař Feb 13 '13 at 14:53
I don't know understand fourth tip "write a custom filter so you can `queryset|order_by:'somefield'`". Could you give me ... some example code? – chobo Feb 13 '13 at 15:04
4

Anyway I solved it. `class Meta: ordering = ['date']` (in models.py) – chobo Feb 13 '13 at 15:06
cathy answer has such sample code, seems like she is using the same [snippet](http://djangosnippets.org/snippets/741/) (but she forgot to attribute the solution to the [original author](http://djangosnippets.org/users/marinho/)). Also, you need to place this file in [some specific location](https://docs.djangoproject.com/en/dev/howto/custom-template-tags/) in order to be able to load it inside the template. – Paulo Scardine Feb 13 '13 at 15:09
@chobo regarding the fourth tip, you may use the link he has provided or refer to this link. https://www.pluralsight.com/guides/create-custom-template-tags-and-filters-in-django . The fourth tip worked for me – Muhammad Zubair Mar 12 '22 at 09:39

Django1.4: How to use order_by in template?

2 Answers2