如何在 Django 的 GenericStackedInline Admin 中访问请求对象

Question

在 Django 1.9 中使用 GenericStackedInline (Python 3.4) 我想在 保存我的模型之前访问 request 对象> 在 Django Admin 中。

当使用MediaItemAdmin 时，我可以在obj.save() 运行之前拦截保存功能，如下例所示：

admin.py

class StuffAdmin(admin.ModelAdmin):
    def save_model(self, request, obj, form, change):
        # Do some stuff here like obj.user = request.user before saving.
        obj.save()

但是，使用GenericStackedInline 无法实现相同的行为或“挂钩”。看来是直接调用模型保存方法了：

admin.py

class StuffAdmin(GenericStackedInline):
    model = StuffModel

    def save_model(self, request, obj, form, change):
        print("I'm never run :(")
        obj.save()

据我所知，GenericStackedInline 继承自 form，所以我也尝试使用表单并覆盖它，如本例所示：

admin.py

class StuffAdmin(GenericStackedInline):
    model = StuffModel
    form = StuffForm

class StuffForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        super(StuffForm, self).__init__(*args, **kwargs)

    def save_model(self, request, obj, form, change):
        print("Still not run!(")
        obj.save()

    def save_form(self, request, obj, form, change):
        print("Work already!")
        obj.save()

我已经搜索了 stackoverflow，但大多数都没有得到答复，如这里所见 accessing request object within a django admin inline model 或说使用 init 执行类似 self.request = kwargs.pop('request') 的操作，但是，request 永远不会在这里传递，对吗？

无论如何，知道如何在调用模型 save() 之前调用请求对象并更新我的实例吗？

Answer 1

保存“内联”的方法是ModelAdmin 的一部分，而不是InlineModelAdmin。

class BarInline(GenericStackedInline):
    model = Bar

class FooModelAdmin(ModelAdmin):
    model = Foo
    inlines = [BarInline]

    def save_formset(self, request, form, formset, change):
        """
        `form` is the base Foo form
        `formset` is the ("Bar") formset to save
        `change` is True if you are editing an existing Foo,
                    False if you are creating a new Foo
        """
        if formset_matches_your_inline_or_some_requirement(formset):
            do_something_with(request)
        super().save_formset(request, form, formset, change)

如果你想检查formset是否是BarInline的formset，你可以这样做：

class BarInline(GenericStackedInline):
    model = Bar

    def get_formset(self, *args, **kwargs):
        formset = super().get_formset(*args, **kwargs)
        formset.i_come_from_bar_inline = True
        return formset


class FooModelAdmin(ModelAdmin):
    model = Foo
    inlines = [BarInline]

    def save_formset(self, request, form, formset, change):
        if getattr(formset, 'i_come_from_bar_inline', False):
            do_something_with(request)
        super().save_formset(request, form, formset, change)

或者更好，让它通用：

class BarInline(GenericStackedInline):
    model = Bar

    def pre_save_formset(self, request, form, model_admin, change):
       """Do something here with `request`."""

class FooModelAdmin(ModelAdmin):
    model = Foo
    inlines = [BarInline]

    def save_formset(self, request, form, formset, change):
        if hasattr(formset, 'pre_save_formset'):
            formset.pre_save_formset(request, form, self, change)
        super().save_formset(request, form, formset, change)
        if hasattr(formset, 'post_save_formset'):
            formset.post_save_formset(request, form, self, change)

---

如果您需要在每个表单保存之前而不是在每个表单集之前对请求执行某些操作，则必须使用自己的 Form 和 FormSet 将请求通过表单集传播到表单：

from django.forms import ModelForm
from django.forms.models import BaseInlineFormSet

class BarForm(ModelForm):
    model = Bar

    def __init__(self, *args, **kwargs):
        request = kwargs.pop('request', None)
        super().__init__(*args, **kwargs)
        self.request = request

    def save(self, commit=True):
        print(self.request)
        print(self.instance)
        obj = super().save(False)  # Get object but don't save it
        do_something_with(self.request, obj)
        if commit:
            obj.save()
            self.save_m2m()
        return obj

class BarFormSet(BaseInlineFormSet):

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

    @request.setter
    def request(self, request):
        self._request = request
        for form in self.forms:
            form.request = request

class BarInline(GenericStackedInline):
    codel = Bar
    form = BarForm
    formset = BarFormSet


class FooModelAdmin(ModelAdmin):
    inlines = [BarInline]

    def _create_formsets(self, request, obj, change):
        formsets, inline_instances = super()._create_formsets(request, obj, change)
        for formset in formsets:
            formset.request = request
        return formsets, inline_instances

根据您的用例，保存方法也可能看起来像这样：

class BarForm(ModelForm):
    model = Bar

    def save(self, commit=True):
        do_something_with(self.request, self.instance)
        return super().save(commit)  # Get object but don't save it

Answer 2

管理类不继承自表单；它们包括形式。而且 ModelForms 没有 save_model 或 save_form 方法，它们只有 save 方法。完全可以覆盖该方法，但它不接受request；您还需要覆盖 __init__ 以接受该参数并将其从模型管理员的 get_form_kwargs 方法传入。