如何在 Django 内联管理表单中创建过滤下拉列表

如何解决如何在 Django 内联管理表单中创建过滤下拉列表

我正在寻求根据用户选择向 DJANGO 中的内联表单添加下拉列表。我需要一个 PYTHONIC 解决方案，请不要使用 jquery 或 javascript。

我已经阅读了两种方法。第一个是创建第二个表单并覆盖默认表单集并更改 init 函数。

使用内联 formfield_for_foreignkey 选项的第二种方法。

两者都不起作用，因为我无法获取表单的上下文数据。

用例是我需要抓取表单上的一个字段。然后我希望将该变量用于相关的模型变量。

在此处上传了 OrderItem 管理表单的屏幕截图。

我希望获取订单项上的“产品”行。使用该 PRODUCT 实例，然后我想访问该产品实例的“packaging”变量。

我遇到的问题是上述两个选项都无法轻松访问表单值。

代码如下：

相关模型

class OrderItem(models.Model):
    rx_written = models.DateField(default=datetime.date.today)
    order = models.ForeignKey(Order,related_name='items',on_delete=models.CASCADE)
    product = models.ForeignKey(Product,related_name='order_items',on_delete=models.CASCADE)   
    doctor = models.ForeignKey(Practitioner,on_delete=models.CASCADE,blank=True,null=True)
    pet = models.ForeignKey(Pet,null=True)
    price = models.DecimalField(max_digits=10,decimal_places=2,null=True)
    tax = models.DecimalField(max_digits=10,null=True)
    quantity = models.PositiveIntegerField(default=1,null=True)
    tot_cost = models.DecimalField(max_digits=10,null=True)
    #shipping_address = models.ForeignKey(ShippingAddress,null=True)
    packaging = models.ForeignKey(Sales_Packaging,null=True)
    

    def __str__(self):
        return '{}'.format(self.id)



    #####override save method #####    
    def save(self,*args,**kwargs):
        self.price = self.product.price
        self.tot_cost = self.product.price * self.quantity
        super(OrderItem,self).save(*args,**kwargs)

    @receiver(post_save,sender=Order)
    def set_tot_cost(sender,instance,**kwargs):
        for i in instance.items.all():
            price = i.product.price
            set_tot_cost = i.product.price * i.quantity
            tot_tax = set_tot_cost/11
            OrderItem.objects.update(price=price,tot_cost=set_tot_cost,tax=tot_tax)
    
class Product(models.Model):
    formula = models.ForeignKey(Formula,related_name='formula',null=True)
    category = models.ForeignKey(Category,related_name='products',on_delete=models.CASCADE)
    name = models.CharField(max_length=200,db_index=True,null=True,blank=True)
    form = models.ForeignKey(Form,blank=True)
    target_species = models.ForeignKey(Target_Species,blank=True)
    packaging = models.ManyToManyField(Sales_Packaging,blank=True)
    slug = models.SlugField(max_length=200,blank=True)
    image = models.ImageField(upload_to='product_img/%Y/%m/%d',blank=True)
    description = models.TextField(blank=True)
    price = models.DecimalField(max_digits=10,blank=True)
    tax = models.DecimalField(max_digits=10,default=0)
    qty = models.IntegerField(blank=True,default=0) 
    available = models.BooleanField(default=True)
    #compound = models.BooleanField(default=True)
    GST = models.BooleanField(default=True)
    created = models.DateTimeField(auto_now_add=True)
    updated = models.DateTimeField(auto_now=True)
   
    #def __str__(self):
    #    return str("%s (%s)" % (self.name,",".join(Sales_Packaging.short_desc for sales_packaging in self.sales_packagings.all()),))
    
    class Meta:
        ordering = ('name',)
        index_together = (('id','slug'),)

    def get_absolute_url(self):
        return reverse('shop:product_detail',args=[self.id,self.slug])


    def get_name(self):
        for item in self.product_line_set.all():
            name = str(item.active) +str(" ")+str(item.strength)+str(" ")+str(item.UoM) + str(qty)+str(" ")++str("in")++str(" ")+str(packaging)
        return name

    def __str__(self):
        return str(self.name)
    #####override save method #####    
    def save(self,**kwargs):
        self.slug=slugify(str(self.name)+str(" ")+str(self.form)+str(" ")+str(self.qty)+str(" "))
        super(Product,**kwargs)

    def __str__(self):
        return str(self.name) + str(" ") + str(self.form) + str(" ") +  str(self.qty)

管理员选项 A：覆盖新模型表单的初始化

from django import forms
from django.contrib.auth.models import User
from .models import Order,OrderItem
from users.models import Customer
#from localflavor.us.forms import USZipCodeField
from django.forms.models import inlineformset_factory
from Product.models import Product,Sales_Packaging
import logging
class OrderItemInlineForm(forms.ModelForm):
    
    class Meta:
        model = OrderItem
        exclude = ('pet','doctor',)
        extra = 0
    def __init__(self,**kwargs):
        super().__init__(*args,**kwargs)
        logger = logging.getLogger("mylogger")
        #qs = OrderItem.objects.get(pk=self.instance)
        #logger.info(qs)
        self.fields['packaging'].queryset = Sales_Packaging.objects.all()

选项 B formfield_for_foreignkey

class OrderItemInline(admin.TabularInline):
   fields = ('rx_written','product','packaging','pet','price','quantity','tax','tot_cost')
   model = OrderItem
   form = OrderItemInlineForm
   extra = 0
   def get_formset(self,request,obj=None,**kwargs):
       OrderItemInline.obj = obj
       return super(OrderItemInline,self).get_formset(request,obj,**kwargs)

   def formfield_for_foreignkey(self,db_field,**kwargs):
       if db_field.name == "packaging":
           try:
               kwargs["queryset"] = Sales_Packaging.objects.filter(short_desc__in=['1 box','500ml Tub'])
           except IndexError:
               pass
       return super().formfield_for_foreignkey(db_field,**kwargs)