CODEWITHSUNDEEP
djangodjango-modelsdjango-templates
Jaskaran Singh
Jaskaran Singh

Reputation: 85

Display a calculated value from models in a template in Django

I want to show the calculated discount under every product. The code below has no errors, but it does not display the value.

models.py:

from django.db import models
# Create your models here.
CATEGORIES = (  
    ('Electronics', 'Electronics'),
    ('Clothing', 'Clothing'),
)

class Products(models.Model):
    Image = models.FileField()
    ProductName = models.CharField(max_length = 250, default='')
    Brand = models.CharField(max_length = 250, default='')
    OriginalPrice = models.IntegerField(default = '')
    Price = models.IntegerField(default = '')
    Category = models.CharField(max_length = 250, choices = CATEGORIES)

    class Meta:
        verbose_name = 'Product'
        verbose_name_plural = 'Products'

    def DiscountCalc(self):
        Discount = (Price/OriginalPrice) * 100
        return self.Discount

    def __str__ (self):
        return self.ProductName

This is the template index.html:

{% for product in AllProducts %}
    <article class="product col-sm-3">
        <a href="#" class="prodlink">
            <img src="{{ product.Image.url }}" class="prodimg img-responsive">
            <p class="prodname">{{ product.ProductName }}</p>
            <span class="origprice">₹{{ product.OriginalPrice }}</span>
            <span class="price">₹{{ product.Price }}</span>
            <div class="discount">
                <p>{{ product.Discount }}% off</p>
            </div>
        </a>
    </article>
{% endfor %}

Upvotes: 0

Views: 1731

Answers (2)

MaximeK
MaximeK

Reputation: 2061

you need to make a property :

@property
def Discount(self):
    return (self.Price/self.OriginalPrice) * 100

So now you can use product.Discount :)

Docs here Django model-methods

Upvotes: 5

PyManiac
PyManiac

Reputation: 504

1)Defining a local variable and Returning a class variable will return null

2)You have to have the same name in models and template

models.py

def DiscountCalc(self):
    Discount = (Price/OriginalPrice) * 100
    return Discount

index.html

{% for product in AllProducts %}
    <article class="product col-sm-3">
        <a href="#" class="prodlink">
            <img src="{{ product.Image.url }}" class="prodimg img-responsive">
            <p class="prodname">{{ product.ProductName }}</p>
            <span class="origprice">₹{{ product.OriginalPrice }}</span>
            <span class="price">₹{{ product.Price }}</span>
            <div class="discount">
                <p>{{ product.DiscountCalc }}% off</p>
            </div>
        </a>
    </article>
{% endfor %}

Upvotes: 1

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