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

Question

I've added a method highlight_link to my model's admin.py class:

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

It returns a custom link for (I've left out highlight_link.short_description for brevity) each record returned in the change list. Which is great. But I'd like to inspect the current query string and change the custom link based on that. Is there a way to access the request object within highlight_link ?

Answer 1

I solve my issue this way.

class MyClassAdmin(admin.ModelAdmin):

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

Now i can use self.request in any place

UPDATE

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

Described how to refactor this into a mixin , with addition of the thread-safety bit based on @taha-jahangir's answer. Here's the mixin:

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)

Subclass ModelAdmin with the mixin:

class PollAdmin(ModelAdminRequestMixin, admin.ModelAdmin):
    pass

... and you can just call self.get_request() from any method.

Answer 4

Small code clarify for Diego Puente answer (python 3.6):

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)

So you can get self.request from any other method of MyClassAdmin .

If define self.request in get_queryset method (without declaring it in __init__ ) PyCharm will generate warning Instance attribute attribute_name defined outside __init__ .

Answer 5

The is no direct way to accomplish this. I see 2 possible solutions.

• Use a thread locals store to same request object

  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')

• If you are using simple non-threaded Django installation it is possible to save request object just as attribute:

   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 6

This is edited version of @user27478 answer, which uses thread-local vars:

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

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 8

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.

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

Answer 9

I tried the other answers left here and ran into issues that for me, were getting complex. I played around with def __call__() and came up with the following. This probably isn't the correct way to do this, but it works...

grab the GET variable here (all within class RadioGridAdmin as described above in my initial post):

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

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

and since it's global, you can now access it here:

def highlight_link(self):
    # access start_date here

Answer 10

What's wrong with this:

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