Django admin的一些有用定制
Model实例,myapp/models.py：
from django.db import models
class Blog(models.Model):
name = models.CharField(max_length=100)
tagline = models.TextField()
# On Python 3: def __str__(self):
def __unicode__(self):
return self.name
class Author(models.Model):
name = models.CharField(max_length=50)
email = models.EmailField()
# On Python 3: def __str__(self):
def __unicode__(self):
return self.name
class Entry(models.Model):
blog = models.ForeignKey(Blog)
headline = models.CharField(max_length=255)
body_text = models.TextField()
pub_date = models.DateField()
mod_date = models.DateField()
authors = models.ManyToManyField(Author)
n_comments = models.IntegerField()
n_pingbacks = models.IntegerField()
rating = models.IntegerField()
# On Python 3: def __str__(self):
def __unicode__(self):
return self.headline
类级别权限
默认情况下，superuser可以访问admin界面的所有Model，但有时候只想让一些用户只能访问一些特定的Model。
可以定制自己的User对象的has_perm()方法：
class MyUser(AbstractBaseUser):
...
def has_perm(self, perm, obj=None):
if self.is_superuser:
return True
elif self.can_edit:
if perm=='myapp.add_entry':
return True
else:
return False
else:
return False
这样superuser具有全部权限。普通user的can_edit属性为True时，就具有了创建Entry实例的权限，其余用户无权限。
也可以定制ModelAdmin的has_add_permission(),has_change_permission(),has_delete_permission()方法：
def has_add_permission(self, request):
"""
Returns True if the given request has permission to add an object.
Can be overridden by the user in subclasses.
"""
opts = self.opts
codename = get_permission_codename('add', opts)
if request.user.can_edit:
return True
else:
return request.user.has_perm("%s.%s" % (opts.app_label, codename))
字段级别的权限
不同权限的可以编辑不同的内容，可以通过get_readonly_fileds()来添加字段只读权限。
class EntryAdmin(admin.ModelAdmin):
list_display=(...)
search_fields=(...)
def get_readonly_fields(self,request,obj=None):
if not request.user.is_superuser and not request.user.can_edit:
return [f.name for f in self.model._meta.fields]
return self.readonly_fields
重写Model的save行为
可以直接重写model的save()方法：
from django.db import models
class Blog(models.Model):
name = models.CharField(max_length=100)
tagline = models.TextField()
def save(self, *args, **kwargs):
do_something()
super(Blog, self).save(*args, **kwargs) # Call the "real" save() method.
do_something_else()
阻止save()：
from django.db import models
class Blog(models.Model):
name = models.CharField(max_length=100)
tagline = models.TextField()
def save(self, *args, **kwargs):
if self.name == "Yoko Ono's blog":
return # Yoko shall never have her own blog!
else:
super(Blog, self).save(*args, **kwargs) # Call the "real" save() method.
也可以重写ModelAdmin的save_model()方法，根据不同的用户定制不同的save行为：
from django.contrib import admin
class ArticleAdmin(admin.ModelAdmin):
def save_model(self, request, obj, form, change):
obj.user = request.user
obj.save()
其中obj是修改后的对象，当新建一个对象时 change = False, 当修改一个对象时 change = True，可以获得修改前的对象：
from django.contrib import admin
class ArticleAdmin(admin.ModelAdmin):
def save_model(self, request, obj, form, change):
if change:
obj_old = self.model.objects.get(pk=obj.pk)
else:
obj_old = None
obj.user = request.user
obj.save()
不同的用户显示不同的数据行，重写列表页面返回的查询集
ModelAdmin提供了一个钩子程序 —— 它有一个名为queryset() 的方法，该方法可以确定任何列表页面返回的默认查询集。
class MyModelAdmin(admin.ModelAdmin):
def get_queryset(self, request):
qs = super(MyModelAdmin, self).get_queryset(request)
if request.user.is_superuser:
return qs
return qs.filter(author=request.user)
定制过滤器list_filter
从django.contrib.admin.SimpleListFilter继承一个子类，提供title和parameter_name属性，并重写 lookups和queryset方法。
from datetime import date
from django.contrib import admin
from django.utils.translation import ugettext_lazy as _
class DecadeBornListFilter(admin.SimpleListFilter):
# Human-readable title which will be displayed in the
# right admin sidebar just above the filter options.
title = _('decade born')
# Parameter for the filter that will be used in the URL query.
parameter_name = 'decade'
def lookups(self, request, model_admin):
"""
Returns a list of tuples. The first element in each
tuple is the coded value for the option that will
appear in the URL query. The second element is the
human-readable name for the option that will appear
in the right sidebar.
"""
return (
('80s', _('in the eighties')),
('90s', _('in the nineties')),
)
def queryset(self, request, queryset):
"""
Returns the filtered queryset based on the value
provided in the query string and retrievable via
`self.value()`.
"""
# Compare the requested value (either '80s' or '90s')
# to decide how to filter the queryset.
if self.value() == '80s':
return queryset.filter(birthday__gte=date(1980, 1, 1),
birthday__lte=date(1989, 12, 31))
if self.value() == '90s':
return queryset.filter(birthday__gte=date(1990, 1, 1),
birthday__lte=date(1999, 12, 31))
class PersonAdmin(admin.ModelAdmin):
list_filter = (DecadeBornListFilter,)
parameter_name和title是必须的。look_up方法返回出现在列表页右侧过滤器中的选项和描述。parameter_name为附加在url后面get请求的参数名，self.value()返回该参数对应的值。
根据不同的用户定制：
class AuthDecadeBornListFilter(DecadeBornListFilter):
def lookups(self, request, model_admin):
if request.user.is_superuser:
return super(AuthDecadeBornListFilter,
self).lookups(request, model_admin)
def queryset(self, request, queryset):
if request.user.is_superuser:
return super(AuthDecadeBornListFilter,
self).queryset(request, queryset)
model_admin为ModelAdmin实例：
class AdvancedDecadeBornListFilter(DecadeBornListFilter):
def lookups(self, request, model_admin):
"""
Only show the lookups if there actually is
anyone born in the corresponding decades.
"""
qs = model_admin.get_queryset(request)
if qs.filter(birthday__gte=date(1980, 1, 1),
birthday__lte=date(1989, 12, 31)).exists():
yield ('80s', _('in the eighties'))
if qs.filter(birthday__gte=date(1990, 1, 1),
birthday__lte=date(1999, 12, 31)).exists():
yield ('90s', _('in the nineties'))
定制搜索功能
class PersonAdmin(admin.ModelAdmin):
list_display = ('name', 'age')
search_fields = ('name',)
def get_search_results(self, request, queryset, search_term):
queryset, use_distinct = super(PersonAdmin, self).get_search_results(request, queryset, search_term)
try:
search_term_as_int = int(search_term)
except ValueError:
pass
else:
queryset |= self.model.objects.filter(age=search_term_as_int)
return queryset, use_distinct
queryset是查询集，search_term是搜索词。
外键字段过滤
在添加对象时显示外键选项时，太多的选项不太友好，这时候需要过滤出符合要求的对象供选择。
class MyModelAdmin(admin.ModelAdmin):
def formfield_for_foreignkey(self, db_field, request, **kwargs):
if db_field.name == "car":
kwargs["queryset"] = Car.objects.filter(owner=request.user)
return super(MyModelAdmin, self).formfield_for_foreignkey(db_field, request, **kwargs)