Django Admin 实现外键过滤

说明和 Model

环境：

➜  python
Python 3.6.3 |Anaconda custom (x86_64)| (default, Oct  6 2017, 12:04:38)
[GCC 4.2.1 Compatible Clang 4.0.1 (tags/RELEASE_401/final)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> print(django.get_version())
2.0.1
>>>

有一个支持多用户（使用 django admin）的 Blog，每一篇 Post 都需要记录是谁发表的并且属于那个 Blog。

user 与 Blog 的关系、 Blog 与 Post 有2种定义方式，一种是使用独立关系表，另外一种是直接在 Model 中定义中使用外键。

后面一种的 model 定义如下：

from django.contrib.auth.models import User
from django.db import models

class Blog(models.Model):
'''
Blog
'''
id = models.AutoField(unique=True, primary_key = True, verbose_name="序号")
name = models.CharField(max_length=255, blank=True, null=True, verbose_name="名称")
user = models.ForeignKey(User, on_delete=models.CASCADE)
create_time = models.DateTimeField(verbose_name='添加时间', auto_now_add=True, blank=True)

class Meta:
verbose_name = 'Blog'
verbose_name_plural = 'Blog管理'

def __str__(self):
return self.name

class Post(models.Model):
'''
Post 内容
'''
id = models.AutoField(unique=True, primary_key = True, verbose_name="序号")
title = models.CharField(max_length=255, blank=True, null=True, verbose_name="标题")
content = models.TextField(max_length=1024, blank=True, null=True, verbose_name="内容")
blog = models.ForeignKey(Blog, on_delete=models.CASCADE, verbose_name="所属Blog")
user = models.ForeignKey(User, on_delete=models.CASCADE)
create_time = models.DateTimeField(verbose_name='添加时间', auto_now_add=True, blank=True)

class Meta:
verbose_name = '文章'
verbose_name_plural = '文章管理'

def __str__(self):
return self.title

Admin 中实现

admin 中有2处，一处是 Blog 和 Post 列表中按 user 过滤，另外一处是新增 Post 时需要按当前 user 过滤。完整代码如下：

from django.contrib import admin
from django import forms

# Register your models here.
from django_summernote.admin import SummernoteModelAdmin
from .models import Team, Member, Activity, Score

from .models import Blog, Post
class FilterUserAdmin(admin.ModelAdmin):
'''
按所属用户过滤的 base, class
'''
def save_model(self, request, obj, form, change):
# TODO 需要考虑不同用户对同一数据进行修改。
obj.user = request.user
obj.save()

def get_queryset(self, request):
# For Django < 1.6, override queryset instead of get_queryset
qs = super(FilterUserAdmin, self).get_queryset(request)
# 不能加这个，加了这个会导致 superuser 更新普通用户的数据。
# if request.user.is_superuser:
#     return qs
return qs.filter(user=request.user)

def has_change_permission(self, request, obj=None):
has_class_permission = super(FilterUserAdmin, self).has_change_permission(request, obj)
if not has_class_permission:
return False
if obj is not None and not request.user.is_superuser and request.user.id != obj.user.id:
return False
return True

class BlogConfigAdmin(FilterUserAdmin):
list_display = ('id','name', 'create_time')
exclude = ['user']
list_per_page = 50

admin.site.register(Blog, BlogConfigAdmin)

class PostConfigAdmin(FilterUserAdmin):
list_display = ('id','title', 'create_time')
exclude = ['user']
list_per_page = 50

def render_change_form(self, request, context, add=False, change=False, form_url='', obj=None):
# 新增 Post 时，相关联的 Blog 需要过滤，关键就在下面这句。
context['adminform'].form.fields['blog'].queryset = Team.objects.filter(user=request.user)
return super(MemberConfigAdmin, self).render_change_form(request, context, add, change, form_url, obj)

admin.site.register(Post, PostConfigAdmin)

说2句

在render_change_form中下断点，直接调试下会发现更多有趣的内容。