我如何在模板上的新字段中发送模型数据

How i can do custom fields for my Model and send it to tempalte?

我如何为我的模型做自定义字段并将其发送到tempalte？

supp - new property for Dish model. If i do print (i.dish.supp) i will see Supplement objects But in template i don't have it... how i can get it in template.

supp - Dish模型的新属性。如果我打印（i.dish.supp）我将看到补充对象但在模板中我没有它...我怎么能在模板中得到它。

    def get_context_data(self, **kwargs):
    context = super(CartView, self).get_context_data(**kwargs)
    user = self.request.user

    try:
        if user.is_authenticated():
            userorders = UserOrder.objects.filter(user_id=user.id,
                                                  is_closed=0)
        else:
            user_hash = self.request.session.get('user_hash')
            userorders = UserOrder.objects.filter(user_hash=user_hash,
                                                  is_closed=0)
    except ObjectDoesNotExist:
        context['data_dish'] = []
        return context

    try:
        context['address'] = UserAddress.objects.get(
            user_id=user.id,
            is_main=1)
    except ObjectDoesNotExist:
        context['address'] = False

    for order in userorders:
        summ = order.order_summ = order.userorder.filter(
            order_id=order.id).aggregate(Sum('price'))
        for i in order.userorder.all():
            sum = Supplement.objects.filter(
                id__in=eval(i.supplements)).aggregate(
                s=Sum('price'))

            i.dish.supp = Supplement.objects.filter(
                id__in=eval(i.supplements)).values('name')

    context['orders'] = userorders
return context

in tempklate

在tempklate

......

......

{% for order in orders.all %}

    <div class="main_order_{{  order.shop.id }} cart" >

        <div class="cart-title">
            <a href="/shop/{{ order.shop.id }}/">{{ order.shop.name }}</a>
            {% for shop, msg in shop_msg %}{% if shop == order.shop %}{{ msg|safe|escape }}{% endif %}{% endfor %}
        </div>

        {% for i in order.userorder.all %}
            <div class="cart-item">
                <div class="col-xs-6 col-sm-3">
                    <img src="{% static 'img/roll.png' %}" alt="" width="90">
                    <div class="info">
                        <h5>{{ i.dish.name }}</h5>
                        <span>Салат, {{ i.dish.weight }} г.</span>
                    </div>
                </div>

but

但

{{ i.dish.supp }}

is empty

是空的

2 个解决方案

#1

Assuming you pasted all of the code from your get_context_data() method, the issue is that you aren't returning the context (look at the very last line), nor are you adding i.dish.supp to the context (be careful with those periods, I changed them to underscores here):

假设您粘贴了get_context_data（）方法中的所有代码，问题是您没有返回上下文（查看最后一行），也没有将i.dish.supp添加到上下文中（请注意那些时期，我把它们改成了下划线）：

def get_context_data(self, **kwargs):
    context = super(CartView, self).get_context_data(**kwargs)
    user = self.request.user

    try:
        if user.is_authenticated():
            userorders = UserOrder.objects.filter(user_id=user.id,
                                                  is_closed=0)
        else:
            user_hash = self.request.session.get('user_hash')
            userorders = UserOrder.objects.filter(user_hash=user_hash,
                                                  is_closed=0)
    except ObjectDoesNotExist:
        context['data_dish'] = []
        return context

    try:
        context['address'] = UserAddress.objects.get(
            user_id=user.id,
            is_main=1)
    except ObjectDoesNotExist:
        context['address'] = False

    for order in userorders:
        summ = order.order_summ = order.userorder.filter(
            order_id=order.id).aggregate(Sum('price'))
        for i in order.userorder.all():
            sum = Supplement.objects.filter(
                id__in=i.supplements).aggregate(
                s=Sum('price'))

            i.dish.supp = Supplement.objects.filter(
                id__in=i.supplements).values('name')

            context['i_dish_supp'] = i.dish.supp

    context['orders'] = userorders
    # And now we provide the context
    return context

Also, don't use eval() for id_in - it's not necessary. Keep in mind that in the code I added, there will only be one i_dish_supp. It looks like you want one for each order, but I'm having a hard time understanding what you're trying to accomplish.

另外，不要对id_in使用eval（） - 这不是必需的。请记住，在我添加的代码中，只有一个i_dish_supp。看起来你想要每个订单一个，但我很难理解你想要完成的任务。

You should take a look at ccbv.co.uk it provides a great way to see the class based views, and all of their methods.

你应该看一下ccbv.co.uk，它提供了一种很好的方式来查看基于类的视图及其所有方法。

#2

i do next, in my model

我在我的模型中做下一步

@property
def get_supplements(self):
    return Supplement.objects.filter(id__in=eval(self.supplements))

in template

在模板中

       {% for supp in i.get_supplements %}
           <span>{{ supp.name }}</span>
      {% endfor %}