打印對應於不同尺寸的商品的價格，如果尺寸沒有變化，則打印底價

Question

在我的模型中，我創建了一個新的類別變體，其中我添加了3個變體，像我的第一個產品，如小，中，大。但我想要的是根據變化傳遞價格，並且如果某些產品沒有任何變化，那麼它必須通過數據庫中先前保存的基本價格。

車應用

views.py

from django.shortcuts import render, HttpResponseRedirect 
from django.core.urlresolvers import reverse 
# Create your views here. 

from products.models import Product 
from .models import Cart, CartItem 

def view(request): 
    try: 
     the_id = request.session['cart_id'] 
    except: 
     the_id = None 
    if the_id: 
     cart = Cart.objects.get(id=the_id) 
     context = {"cart": cart} 
    else: 
     empty_message = "Your Cart is Empty, please keep shopping." 
     context = {"empty": True, "empty_message": empty_message} 

    template = "cart/view.html" 
    return render(request, template, context) 

def update_cart(request, id): 
    request.session.set_expiry(120000) 
    try: 
     qty = request.GET.get('qty') 
     update_qty = True 
    except: 
     qty = None 
     update_qty = False 



    try: 
     the_id = request.session['cart_id'] 
    except: 
     new_cart = Cart() 
     new_cart.save() 
     request.session['cart_id'] = new_cart.id 
     the_id = new_cart.id 

    cart = Cart.objects.get(id=the_id) 

    try: 
     product = Product.objects.get(id=id) 
    except Product.DoesNotExist: 
     pass 
    except: 
     pass 

    cart_item, created = CartItem.objects.get_or_create(cart=cart, product=product) 
    if created: 
     print "yeah" 


    if update_qty and qty: 
     if int(qty) == 0: 
      cart_item.delete() 
     else: 
      cart_item.quantity = qty 
      cart_item.save() 
    else: 
     pass   


    new_total = 0.00 
    for item in cart.cartitem_set.all(): 
     line_total = float(item.product.price) * item.quantity 
     new_total += line_total 

    request.session['items_total'] = cart.cartitem_set.count() 
    cart.total = new_total 
    cart.save() 

    return HttpResponseRedirect(reverse("cart")) 

產品應用

models.py

from django.db import models 

# Create your models here. 
class Product(models.Model): 
    title = models.CharField(max_length=120) 
    description = models.TextField(null=True, blank=True) 
    price = models.DecimalField(decimal_places=2, max_digits=100, default=29.99) 
    sale_price = models.DecimalField(decimal_places=2, max_digits=100, null=True, blank=True) 

    #image = models.FileField(upload_to='products/images/', null=True) 
    slug = models.SlugField() 
    timestamp = models.DateTimeField(auto_now_add=True, auto_now=False) 
    update = models.DateTimeField(auto_now_add=False, auto_now=True) 
    active = models.BooleanField(default=True) 

    def __unicode__(self): 
     return self.title 

    def get_price(self): 
     return self.price 

class ProductImage(models.Model): 
    Product = models.ForeignKey(Product) 
    image = models.ImageField(upload_to='products/images/') 
    featured = models.BooleanField(default=False) 
    thumbnail = models.BooleanField(default=False) 
    active = models.BooleanField(default=True) 
    updated = models.DateTimeField(auto_now_add=False, auto_now=True) 

    def __unicode__(self): 
     return self.Product.title 


class Variation(models.Model): 
    product = models.ForeignKey(Product) 
    #category = models.CharField(max_length=120, choices=VAR_CATEGORIES, default='size') 
    title = models.CharField(max_length=120) 
    image = models.ForeignKey(ProductImage, null=True, blank=True) 
    price = models.DecimalField(max_digits=100, decimal_places=2, null=True, blank=True) 
    updated = models.DateTimeField(auto_now_add=False, auto_now=True) 
    active = models.BooleanField(default=True) 

    #objects = VariationManager() 

    def __unicode__(self): 
     return self.title  

HTML塊

{% block product%} 
    <div class='row'> 

    {% for product in products %} 
    <div class='col-sm-4'> 
    {% for item in product.productimage_set.all %} 
     <div class="thumbnail"> 
    <img class='img-responsive' src="{{ MEDIA_URL }}{{ item.image }}" /><br> 
    <div class="caption"> 
    <h3>{{ product.title }}</h3> 
    <h5>{{ product.price }}</h5> 
    <p>{{ product.description }}</p> 

    <form method='GET' action='{% url "update_cart" product.id %}'> 

    <input name='qty' type='number' value='1' /> 

    <input type='submit' class="btn btn-primary" value='Add to cart'/> 

    {% if product.variation_set.all %} 
    <select name='size'> 
    {%for item in product.variation_set.all %} 
    <option value='{{ item.title|lower }}'>{{ item.title|capfirst }}</option> 
    {% endfor %} 

    </select> 
    {% endif %} 


    </form> 


    </div> 
</div> 


    {% endfor %} 

    </div> 

    {% endfor %} 

    </div> 

{% endblock %} 

{% block content %} 
{% endblock %} 

Answer 1

你不能把邏輯放在get_price()？

def get_price(self): 
    if check_for = variation 
     return preferred_price 
    else: 
     return self.price 

你會先Purchase.get_price()

調用它。如果你想加快速度，你可以用一個屬性裝飾緩存值。例如：

@property 
def adjusted_price(self): 
    if check_for = variation 
     return preferred_price 
    else: 
     return self.price 

這與Purchase.adjusted_price