python - 模板包含标记 : Choose another template if it does not exist

Question

我想根据请求包含一个不同的模板。例如:

假设请求有:

request.country = 'Spain'
request.city = 'Madrid'

我想包含“index.html” View 但是:

----如果myapp/index_madrid.html存在

{% include "myapp/index_madrid.html" %}

---- elif myapp/index_spain.html 存在

   {% include "myapp/index_spain.html" %}

----否则转到默认版本

   {% include "myapp/index.html" %}

我怎样才能以透明的方式实现这种行为？我的意思是，我想做类似的事情:

{% my_tag_include "myapp/index.html" %}
{% my_tag_include "myapp/another_view.html" with p='xxx' only%}
{% my_tag_include "myapp/any_view.html" with p='sss' a='juan' %}

并实现我之前解释的级联加载。

谢谢

Answer 1

一种可能是在 View 中实现这种逻辑:

# views.py
from django.template.loader import select_template

class MyView(View):
    def get(self, request):
        include_template = select_template([
            'myapp/index_{}.html'.format(request.city),
            'myapp/index_{}.html'.format(request.country),
            'myapp/index.html'
        ])

        ctx = {
            'include_template': include_template
        }

        return render(request, 'myapp/base.html', ctx)

# myapp/base.html
{% include include_template %}

select_template() 将返回传递的列表中存在的第一个模板。 include 标签支持包含从 Django 1.7 开始的已编译模板，因此如果您使用的是 1.7 或更高版本，这应该可以正常工作。

---

更新:跨多个 View 重用

# utils.py
from django.template.loader import select_template

def get_approriate_template(tokens, app_name):
    templates = ['{}/index_{}.html'.format(app_name, x) for x in tokens]
    templates.append('{}/index.html'.format(app_name))
    return select_template(templates)

# views.py
from .utils import get_approriate_template

class MyView(View):
    def get(self, request):
        tokens = [request.city, request.country]
        ctx = {
            'include_template': get_appropriate_template(tokens, app_name='myapp')
        }

        return render(request, 'myapp/base.html', ctx)

---

更新:从模板标签渲染模板

# templatetags/myapp_extras.py
from django import template

register = template.Library()

@register.simple_tag(takes_context=True)
def my_tag_include(context):
    from django.template.loader import select_template
    include_template = select_template([
        'myapp/index_{}.html'.format(context['request'].city),
        'myapp/index_{}.html'.format(context['request'].country),
        'myapp/index.html'
    ])
    return include_template.render(context)

# myapp/base.html
{% load myapp_extras %}
{% my_tag_include %}