How to multiply two variables together in HTML template DJANGO-CodePudding

I have this page that lists various info on a specific stock including orders that have been placed on that specific item. I would like to display how much money the user of this system would get from that specific order.

<table class='table'>
        <thead>
          <tr>
            <th>ORDER ID</th>
            <th>NAME</th>
            <th>AMOUNT ORDERED</th>
            <th>REVENUE</th>
            <th>ORDERED ITEM</th>
            <th>ADDRESS</th>
            <th>CITY</th>
            
          </tr>
        </thead>
      {% for x in queryset2 %}
          <tr>
            <td>{{x.id}}</td>
            <td>{{x.name}}</td>
            <td>{{x.quantity}}</td>
            <td>{{x.quantity * stock.ppu}}</td>
            <td>{{x.order_item}}</td>
            <td>{{x.address}}</td>
            <td>{{x.city}}</td>
          </tr>
      {% endfor %}
    </table>

I have this code so far. What would be the correct syntax to multiply these two variables together : {{x.quantity * stock.ppu}}

CodePudding user response：

You can not write arithmetic expressions in a Django template. You should write this in the view, for example by annotating the queryset:

from django.db.models import F

# …

queryset2 = queryset2.annotate(
    total_value=F('quantity') * F('ppu')
)

then in the template you render this as:

<td>{{ x.total_value }}</td>

CodePudding user response：

To do math operations in the Django template you can use this django-mathfilters

but if you try to use a built-in way to do, can follow this to add and Subtraction

Example:

{{x.quantity | add: stock.ppu}}

to do multiplication and division you can use widthratio

Example:

a*b use {% widthratio a 1 b %}
a/b use {% widthratio a b 1 %}

from this answer

or you can make your own custom tags

for add

@register.filter
def add_value(value, arg):
    return value   arg

for subtract

@register.filter
def subtract(value, arg):
    return value - arg

then use them in your template like this

{{x.quantity | subtract: stock.ppu}}