django - Django:从内联模型管理员访问父实例

Question

如何从内联模型管理员访问父实例？

我的目标是根据父实例的状态覆盖has_add_permission函数。如果父级的状态不同于1，则我不允许添加子级。

class ChildInline(admin.TabularInline):
    model = Child
    form = ChildForm

    fields = (
        ...
    )
    extra = 0

    def has_add_permission(self, request):
        # Return True only if the parent has status == 1
        # How to get to the parent instance?
        #return True

class ParentAdmin(admin.ModelAdmin):
    inlines = [ChildInline,]

Answer 1

Django <2.0答案：

使用Django的Request对象（您可以访问）检索request.path_info，然后从resolve匹配项中的参数中检索PK。例：

from django.contrib import admin
from django.core.urlresolvers import resolve
from app.models import YourParentModel, YourInlineModel


class YourInlineModelInline(admin.StackedInline):
    model = YourInlineModel

    def get_parent_object_from_request(self, request):
        """
        Returns the parent object from the request or None.

        Note that this only works for Inlines, because the `parent_model`
        is not available in the regular admin.ModelAdmin as an attribute.
        """
        resolved = resolve(request.path_info)
        if resolved.args:
            return self.parent_model.objects.get(pk=resolved.args[0])
        return None

    def has_add_permission(self, request):
        parent = self.get_parent_object_from_request(request)

        # Validate that the parent status is active (1)
        if parent:
            return parent.status == 1

        # No parent - return original has_add_permission() check
        return super(YourInlineModelInline, self).has_add_permission(request)


@admin.register(YourParentModel)
class YourParentModelAdmin(admin.ModelAdmin):
    inlines = [YourInlineModelInline]

Django> = 2.0答案：

归功于 Mark Chackerian进行以下更新：

使用Django的Request对象（您可以访问）检索 request.path_info，然后从 resolve匹配项中的参数中检索PK。例：

from django.contrib import admin
from django.urls import resolve
from app.models import YourParentModel, YourInlineModel


class YourInlineModelInline(admin.StackedInline):
    model = YourInlineModel

    def get_parent_object_from_request(self, request):
        """
        Returns the parent object from the request or None.

        Note that this only works for Inlines, because the `parent_model`
        is not available in the regular admin.ModelAdmin as an attribute.
        """
        resolved = resolve(request.path_info)
        if resolved.args:
            return self.parent_model.objects.get(pk=resolved.args[0])
        return None

    def has_add_permission(self, request):
        parent = self.get_parent_object_from_request(request)

        # Validate that the parent status is active (1)
        if parent:
            return parent.status == 1

        # No parent - return original has_add_permission() check
        return super(YourInlineModelInline, self).has_add_permission(request)


@admin.register(YourParentModel)
class YourParentModelAdmin(admin.ModelAdmin):
    inlines = [YourInlineModelInline]