=======
ecscart
=======

ecscart is a module who can manage the caddy of an user.
This module save the product reference, price and quantity.

The caddy has two states, valided or not valided.
The caddy has the possibility to compute rules for the total amount,
like reductions, taxes, delivery prices.

The computed caddy can be published as many format, like xml, json.

Finally the caddy will be persistant in database, to ensure data integrity
during a crash.

Launching the cart
==================

A few initialisation procedure is mandatory to instatiate the `Cart` class. :: 

    >>> from ecs.cart import Cart
    >>> user_id = 'Doriane'
    >>> cart = Cart(user_id)

Adding a product in the caddy
=============================

To add a product into the caddy we must use the `add_product` method.
The first parameters is the reference of the product, the second the price,
and the optional quantity parameters. ::

    >>> cart.add_product('brosse a cheveux', 12.4)
    >>> cart.add_product('lime a ongle', price=3.32, quantity=5)


Set quantity of the product
===========================

You can eventualy change the quantity of a product in a cart by the
`set_quantity` method. ::

    >>> cart.get_product_property('brosse a cheveux', 'quantity')
    1.0
    >>> cart.set_quantity('brosse a cheveux', 2)
    >>> cart.get_product_property('brosse a cheveux', 'quantity')
    2.0


Delete a product
================

You can delete a product by setting his quantity to 0, or most symply
with the `del_product` method. ::

    >>> cart.add_product('fond de teint', 19)
    >>> cart.add_product('mascara', 12)
    ...
    >>> cart.set_quantity('fond de teint', 0)
    >>> cart.del_product('mascara')
    ...
    >>> cart.get_product_property('fond de teint', 'price')
    Traceback (most recent call last):
    ...
    ValueError: Invalid reference fond de teint
    >>> cart.get_product_property('mascara', 'quantity')
    Traceback (most recent call last):
    ...
    ValueError: Invalid reference mascara

Getting the amount of the caddy
===============================

It's symply to have the amount of the caddy using the `get_cart_amount` ::

    >>> amount = cart.get_cart_amount()
    >>> round(amount)
    41.0

Add reductions
==============

You could add reduction on the cart. ::

    >>> cart.add_reduction(5)
    >>> amount = cart.get_cart_amount()
    >>> round(amount)
    36.0

You could delete the reduction

Confirm the caddy
=================

A flag is provided to manage is the caddy is valided. The `validation` method
is also provided  `validation` can take a parameters wich will be the flag value::

    >>> cart.validation_statut
    False
    >>> cart.validation()
    >>> cart.validation_statut
    True
    >>> cart.validation('Not yet')
    >>> cart.validation_statut
    'Not yet'

Removing a caddy for an user
============================

To delete the caddy from the persistence you must use the `remove` method ::

    >>> cart.remove()
    >>> cart.products
    {}

