Django Admin：对于 list_display 方法，如何访问 admin.py 中的请求对象？

Question

我在模型的 admin.py 类中添加了一个方法 highlight_link：

class RadioGridAdmin(admin.ModelAdmin):
    
    list_display = ('start_time', highlight_link)
    
    def highlight_link(self):
        return ('some custom link')
    
    
admin.site.register(RadioGrid, RadioGridAdmin)

它为更改列表中返回的每条记录返回一个自定义链接（为简洁起见，我省略了highlight_link.short_description）。这是伟大的。但我想检查当前的查询字符串并根据它更改自定义链接。有没有办法访问highlight_link中的请求对象？

Answer 1

我通过这种方式解决了我的问题。

class MyClassAdmin(admin.ModelAdmin):

    def queryset(self, request):
        qs = super(MyClassAdmin, self).queryset(request)
        self.request = request
        return qs

现在我可以在任何地方使用self.request

更新

Changed in Django 1.6: The get_queryset method was previously named queryset.

class MyClassAdmin(admin.ModelAdmin):

    def get_queryset(self, request):
        qs = super(MyClassAdmin, self).get_queryset(request)
        self.request = request
        return qs

Answer 2

class RadioGridAdmin(admin.ModelAdmin):

    def highlight_link(self, obj):
        return (self.param)

   def changelist_view(self, request, extra_context=None):
        self.param = request.GET['param']
        return super(RadioGridAdmin,self).changelist_view(request, extra_context=extra_context)

Answer 3

描述了如何refactor this into a mixin，并根据@taha-jahangir 的回答添加了线程安全位。这是混合：

import threading

class ModelAdminRequestMixin(object):
    def __init__(self, *args, **kwargs):
        # let's define this so there's no chance of AttributeErrors
        self._request_local = threading.local()
        self._request_local.request = None
        super(ModelAdminRequestMixin, self).__init__(*args, **kwargs)

    def get_request(self):
        return self._request_local.request

    def set_request(self, request):
        self._request_local.request = request

    def changeform_view(self, request, *args, **kwargs):
        # stash the request
        self.set_request(request)

        # call the parent view method with all the original args
        return super(ModelAdminRequestMixin, self).changeform_view(request, *args, **kwargs)

    def add_view(self, request, *args, **kwargs):
        self.set_request(request)
        return super(ModelAdminRequestMixin, self).add_view(request, *args, **kwargs)

    def change_view(self, request, *args, **kwargs):
        self.set_request(request)
        return super(ModelAdminRequestMixin, self).change_view(request, *args, **kwargs)

    def changelist_view(self, request, *args, **kwargs):
        self.set_request(request)
        return super(ModelAdminRequestMixin, self).changelist_view(request, *args, **kwargs)

    def delete_view(self, request, *args, **kwargs):
        self.set_request(request)
        return super(ModelAdminRequestMixin, self).delete_view(request, *args, **kwargs)

    def history_view(self, request, *args, **kwargs):
        self.set_request(request)
        return super(ModelAdminRequestMixin, self).history_view(request, *args, **kwargs)

使用 mixin 子类 ModelAdmin：

class PollAdmin(ModelAdminRequestMixin, admin.ModelAdmin):
    pass

...您可以通过任何方法调用self.get_request()。

Answer 4

没有直接的方法可以做到这一点。我看到了 2 个可能的解决方案。

• 使用线程本地存储到同一个请求对象

  from django.utils._threading_local import locals
  
  globals = locals()
  
  class RadioGridAdmin(admin.ModelAdmin):
    def __call__(self, request, *args, **kwargs):
        globals['radio_grid_admin_request'] = request
        return super(RadioGridAdmin, self).__call__(request, *args, **kwargs)
  
    def highlight_link(self):
        request = globals['radio_grid_admin_request']
        # request.GET processing
        return ('some custom link')
  

• 如果您使用简单的非线程 Django 安装，可以将请求对象保存为属性：

  class RadioGridAdmin(admin.ModelAdmin):
    def __call__(self, request, *args, **kwargs):
        self.request = request
        return super(RadioGridAdmin, self).__call__(request, *args, **kwargs)
  
    def highlight_link(self):
        # self.request.GET processing
        return ('some custom link')
  

Answer 5

Diego Puente 答案（python 3.6）的小代码说明：

class MyClassAdmin(admin.ModelAdmin):
    def __init__(self, model, admin_site): 
        self.request = None
        super().__init__(model, admin_site)

    def get_queryset(self, request):
        self.request = request      
        return super().get_queryset(request)

所以你可以从MyClassAdmin的任何其他方法获得self.request。

如果在get_queryset 方法中定义self.request（没有在__init__ 中声明）PyCharm 将生成警告Instance attribute attribute_name defined outside __init__。

Answer 6

这是@user27478 答案的编辑版本，它使用线程本地变量：

class RadioGridAdmin(admin.ModelAdmin):
    def __init__(self, model, admin_site):
        super().__init__(model, admin_site)
        self._request_local = threading.local()

    def changelist_view(self, request, extra_context=None):
        self._request_local.request = request
        return super().changelist_view(request, extra_context)

    @property
    def _request(self):
        return self._request_local.request

    def example_highlight_link(self, obj):
        changelist = self.get_changelist_instance(self._request)
        url = changelist.get_query_string(new_params={'key1': 1})

Answer 7

我尝试了此处留下的其他答案，但遇到了对我来说变得越来越复杂的问题。我玩了def __call__() 并想出了以下内容。这可能不是正确的方法，但它确实有效......

在此处获取 GET 变量（所有在 RadioGridAdmin 类中，如我最初的帖子中所述）：

def __call__(self, request, url):
     global start_date
     start_date = request.GET['param']

     return super(RadioGridAdmin, self).__call__(request, url)

由于它是全球性的，您现在可以在这里访问它：

def highlight_link(self):
    # access start_date here

Answer 8

import threading

_thread_local = threading.local()

def get_thread_local_request():
    return getattr(_thread_local, "request", None)

class RadioGridAdmin(admin.ModelAdmin):
    list_display = ('display_field', ...)

    def display_field(self, obj):
        # ...
        request = get_thread_local_request()
        # ... 

Answer 9

admin_mixins.py

​​>

from functools import partial, update_wrapper, lru_cache

# Django admin call 2 times get_list_display.
# We need to return the same function to make the method sortable using 'admin_order_field'
# https://github.com/django/django/blob/2161db0792f2e4d3deef3e09cd72f7a08340cafe/django/contrib/admin/templatetags/admin_list.py#L84
@lru_cache(maxsize=100)
def cache_display_wrap(f, request):
    wf = partial(f, request)
    nf = update_wrapper(wf, f)
    return nf

  
class ModelAdminMixin(admin.ModelAdmin):
  
    def get_list_display(self, request):
        def check_needs_request(display):
            f = getattr(self, display, None) if not callable(display) else display 
            if f and getattr(f, 'needs_request', False):
              return cache_display_wrap(f, request)
            return display
        return [check_needs_request(display) for display in super().get_list_display(request)]

any_app/admin.py

​​>

from django.contrib import admin
from core.admin_mixins import ModelAdminMixin


@admin.register(AnyModel)
class AnyModelAdmin(ModelAdminMixin, admin.ModelAdminMixin):

    list_display = ['id', 'especial_display_with_request']

    def especial_display_with_request(self, request, obj):
        # Make something special with the request
        return obj.any_field
    especial_display_with_request.needs_request = True  # Similar to short_description or any other django admin attr.

来源：https://gist.github.com/pricco/24826bae3d5102d963eb13ecc0493f33

Answer 10

这是怎么回事：

def highlight_link(self, request):
    # access start_date here