Cart2

Simple cart package for Django.

In the past it was sequentially maintained by:

• Eric Woudenberg
• Marc Garcia
• Bruno Carvalho

I made a fork and enriched it by bettering the code and adding features for convenience. All the code is (re)written with a future Python 3 compliance in mind. Python2 is supported using the django.utils.six package which is part of Django as of version 1.5.

The cart is successfully used in a real-world shop without any problems so far.

##Prerequisites

• Django 1.5
• Django Content Types app
• Django Session app

##Installation

1. Add 'cart' to INSTALLED_APPS
2. Run ./manage.py syncdb

##Guide

####Create a cart for current session

import cart

session = request.session or {}
c = cart.Cart(session)

####Add/Remove products from cart

# Add a product
product = myapp.models.Product.objects.get(pk=product_pk)
quantity = 10
c.add(product, quantity)

# Remove a product
product = myapp.models.Product.objects.get(pk=product_pk)
c.remove(product)

####Quantity methods

# Check quantity of product
quantity_of_product = c.quantity(product)

# Increase quantity by one
# Please note that incrby_quantity doesn't check the quantity value
new_quantity = c.incrby_quantity(product, 1)

# Decrease quantity by 2
new_quantity = c.incrby_quantity(product, -2)

####Meta information for products in cart

# Products can now be added to cart with complementary meta information.
# The meta information should always be a dictionary.
product = myapp.models.Product.objects.get(pk=product_pk)
c.add(product, meta={'color': 'black'})

# Get all the meta information for a product
dictionary_or_none = c.meta_for_product(product)

# Access meta information for particular product
value_or_key_error_or_none = c.get_meta(product, 'color')

# Access meta information while iterating over cart items
for item in c:
    value_or_key_error = item.meta['color']

# Set meta information for particular product
c.set_meta(product, 'color', 'pink')

# Set meta information while iterating over cart items
for item in c:
    item.meta['color'] = 'pink'

####Batch operations

product_pks = [1, 2, 3, 4, 5]
product_qts = [6, 7, 8, 9, 10]
products = {
    myapp.models.Product.objects.get(pk=pk) : qt
    for pk, qt in zip(product_pks, product_qts)
}

# Add products at once
c.add_products(products)

# Leave just these products in cart and remove all other
products = myapp.models.Product.objects.filter(pk__in=[1,2,3])
c.remove_different(products)

# Update the cart (by removing all existing products and adding just the new ones)
c.set_products(products)

# Remove all products
c.remove_all()

####State

# Check if the cart is empty
if c.empty:
    pass # yep, it's empty
else:
    pass # not empty

# Get the total number of products inside the cart
total_number_of_products_in_cart = c.total

# Check if a product is in the cart
if product in c:
    pass # Cart has it stored

# Iterate over all items of the cart
for item in cart:
    do_something(item, item.product, item.quantity)

####Use in templates First you have to add the 'cart.context_processors.add_cart' to your TEMPLATE_CONTEXT_PROCESSORS list.

{% if cart.empty %}
    <h1>Your cart is empty</h1>
{% else %}
    <h1>You have {{ cart.total }} products in your cart</h1>
    <ul>
        {% for item in cart %}
            <li>{{ item.quantity }} x {{ item.product }}</li>
        {% endfor %}
    </ul>
{% endif %}

####Template tags There are few template tags that help you:

1. Get the quantity of a product (given you have just the product object at hand).

{% load carttags %}
<h1>{{ product }}</h1>
{% if product in cart %}
    <p>You have {% cart_quantity cart product %} products of this
       type inside your cart.</p>
{% else %}
    <p>This product is not in your cart</p>
{% endif %}

2. Get the meta information for product as json

{% load carttags %}
<script>
    var productMeta = {% cart_meta_as_json cart product %};
</script>

####Remove the cart itself and cleanup the session

import cart

session = request.session
cart.cleanup(session)

###Why it's not on PyPi Actually the original cart is right there under the name django-cart.

Anyway, I don't think that's a serious enough project to take up space there for a cloning with just minor updates as this one. The license is LGPL and you're fully free to fork/copy the code and create a package on your own, if you need such a thing. Suit yourself.

I plan to maintain this cart right here as long as I need it in my work.

###Known problems A lot. It uses the db a lot and makes unnecessary queries.