Django related_name

Question

I'm trying to do something like:

{% for property in current_listing %}
    {% for property_image in property.property_images.all %}

    {% endfor %}
{% endfor %}

But I would like something like:

{% for property in current_listing %}
    {% for property_image in property.property_images.**ORDER_BY('-order')[0]** %}

    {% endfor %}
{% endfor %}

How can I do this?

Answer 1

If I understand what you want, you can try custom template filter :

from django import template
register = template.Library()

@register.filter
def get_first_ordered_by(queryset, order):
    return queryset.order_by(order)[0]

Then on a template:

{% load my_tags %}

{% with image=property.property_images.all|get_first_ordered_by:'-order' %}
    {{ image }}
{% endwith %}

Note, that you can not use {% for %} since result of get_first_ordered_by is not iterable.

Answer 2

您可以在Model的类定义中添加一个方法，以返回所需的查询，然后从您的模板中取消该方法。