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elle

2007-Oct-18 07:14 UTC

cart configuration and sessions

Hi,

I guess as many people, I am very new to Rails. I used a book to
create a shopping cart and then modified the code to try and fit it to
my project''s requirements. I have been trying figure this out for the
last week and starting to get really discouraged about the prospects
of solving this. I know what needs to be done but I''m at a loss for
how to achieve it. So, I wanted to ask, for help. Please please
please.

Background:
I have the following classes: customer, product, cart, cart_items,
order, order_items
A customer needs to login to even see the "Add to cart" links -- so
the same goes for viewing cart and checkout. (which is achieved).
Things I have trouble with:
1) The sessions are stored in the db. Right now, customer session and
cart session are separate. I need to assoociate them together. So,
when a customer loggs out and a new customer logs in, they have
different carts. If the session can remember the cart items, if the
same customer logs in again, that would be great. The customer id will
also need to be stored in the orders tables as well.
2) I suddently have trouble even trying to add an item to the cart.
3) I need to figure out a way to update the quantity of items
(products) in the cart.
4) And lastly, my checkout page doesn''t come up suddenly as well

Please can anyone have a look and help me solve this?
Any help will be so much appreciated,
Thanks,
Elle

-------------------------------------------
MODELS
customer.rb:

class Customer < ActiveRecord::Base
  has_many :orders,
           :dependent => true,
           :order => "created_at ASC"
  has_many :carts

  validates_length_of       :name, :within => 3..40
  validates_uniqueness_of   :name
  validates_length_of       :password, :within => 4..40, :if
=> :password_required?

  def open_orders
    orders.find(:all, :conditions => "status =
''open''")
  end

  def orders_history
    orders.find(:all, :conditions => "status =
''closed''")
  end

  def password=(value)
    write_attribute("password", Digest::SHA1.hexdigest(value))
  end

  def self.authenticate(name,password)
    find(:first, :conditions => ["name = ? and password = ?",name,
Digest::SHA1.hexdigest(password)])
  end

  def self.orders
    current_customer = Customer.find(param[:id])
    orders = current_customer.orders
  end

  def self.carts
    current_customer = Customer.find(param[:id])
    orders = current_customer.carts
  end

end

------------------------------
cart.rb:

class Cart < ActiveRecord::Base
  has_many :cart_items
  has_many :products, :through => :cart_items
  belongs_to  :customer

  def total
    cart_items.inject(0) {|sum, n| n.price * n.amount + sum}
  end

  def add(product_id)
    items = cart_items.find_all_by_product_id(product_id)
    product = Product.find(product_id)
    if items.size < 1
      ci = cart_items.create(:product_id => product_id,
                             :amount => 1,
                             :price => product.price)
    else
      ci = items.first
      ci.update_attribute(:amount, ci.amount + 1)
    end
    ci
  end

  def remove(product_id)
    ci = cart_items.find_by_product_id(product_id)

    if ci.amount > 1
      ci.update_attribute(:amount, ci.amount - 1)
    else
      CartItem.destroy(ci.id)
    end
    return ci
  end

  def update(product_id)
    items = cart_items.find_all_by_product_id(product_id)
    product = Product.find(product_id)
    ci = cart_items
    ci.update_attribute(:amount, ci.amount + 1)

  end

end

-------------------------------
CONTROLLER
cart_controller.rb:

class CartController < ApplicationController
  before_filter :initialize_cart
  before_filter :authorize,    :except => ["login"]

  def authorize
    return true if @c
    flash[:notice] = "To place your order please login"
    redirect_to :controller => "catalog"
  end

  def login
    # examine the form data for "name" and "password"
    pw,name = params[:customer].values_at(*%w{password name})
    # Retrieve the customer record for the name and store it in a
variable ''c''
    c = Customer.find_by_name(name)
    # if such record exists, and it''s password matches the password
from the form
    if c && Digest::SHA1.hexdigest(pw) == c.password
      # start a session with the customer id
      session[:customer] = c.id
      @cart = Cart.create
      session[:customer]

        if @cart.products.empty?
           redirect_to :controller => "catalog"
        else

        redirect_to :action => "view_cart"
        end
    else
      # otherwise report an error
      flash[:notice] = "Invalid Login"
      redirect_to :controller => "catalog"
    end
  end

  def logout
    session[:customer] = nil
    redirect_to :controller => "catalog"
  end

  def index
  end

  def add
    product = Product.find(params[:id])
    if request.post?
      @item = @cart.add(params[:id])
      flash[:notice] = "Added <em>#{@item.product.title}</em>
to
cart."
      redirect_to :controller => "catalog"
    else
      render
    end
  end

  def update
    @product = Product.find(params[:id])
    if request.post?
      @item = @cart.update_attributes(params[:cart])
      flash[:notice] = "Updated
<em>#{@item.product.title}</em>''s
quantity."
      redirect_to :action => "view_cart" and return if @cart.save
    else
      render
    end
  end

  def remove
    @product = Product.find(params[:id])
    if request.post?
      @item = @cart.remove(params[:id])
      flash[:notice] = "Removed
<em>#{@item.product.title}</em>"
      redirect_to :action => "view_cart"
    else
      render
    end
  end

  def clear
    if request.post?
      @cart.cart_items.destroy_all
      flash[:notice] = "Cleared the cart"
      redirect_to :controller => "catalog"
    else
      render
    end
  end

  def view_cart
    @page_title = "Shopping Cart for #{@c.name}"
    @order = Order.new
    if @cart.empty?
      flash[:notice] = "Your shopping cart is empty! Please add
something to it before proceeding to checkout."
      redirect_to :controller => ''catalog''
    end
  end

  def checkout
    @page_title = "Checkout"
    @order = Order.new(params[:order])
    @order.customer_ip = request.remote_ip
    @order.customer_id = @session[''customer'']
    populate_order

    if @order.save
      if @order.process
        flash[:notice] = ''Your order has been submitted, and will be
processed immediately.''
        session[:order_id] = @order.id
        # Empty the cart
        @cart.cart_items.destroy_all
        redirect_to :action => ''thank_you''
      else
        flash[:notice] = "Error while placing order.
''#{@order.error_message}''"
        render :action => ''view_cart''
      end
    else
      render :action => ''view_cart''
    end
  end

  def thank_you
    @page_title = ''Thank You!''
  end


  def populate_order
    for cart_item in @cart.cart_items
      order_item = OrderItem.new(
        :product_id => cart_item.product_id,
        :price => cart_item.price,
        :amount => cart_item.amount
      )
      @order.order_items << order_item
    end
  end

end

------------------------------------------
VIEWS
partial for cart item: _item.rhtml:

<tr>
<td><%=h item.product.sku %></td>
<td><%= link_to item.product.title, :action => "show",
      :controller => "catalog", :id => item.product.id
%></td>
<td><%= pluralize(item.amount, "pc", "pcs")
%></td>
<td>$<%= two_dec(item.price * item.amount) %></td>

<td><%= form_tag :controller => "cart", :action =>
"update", :id =>
item.product, :with => "new_qty" %>
<%= text_field_tag "new_qty", "", "size" =>
4 %>
<input type="Submit", value="Update"/>
<%= end_form_tag %>
</td>
<td><%= button_to "x", :controller => "cart",
:action => "remove", :id
=> item.product %></td>
</tr>

-------------------------------------------------
checkout.rhtml:

<%= error_messages_for ''order'' %>
<p><em>Your order&#8217;s total is: <%=h @cart.total
%></em></p>
<form method="post" id="checkout" action="<%=
url_for :action
=> :checkout %>">
  <fieldset>
    <legend>Contact Information</legend>
    <p><label
for="order_email">Email</label></p>
    <p><%= text_field :order, :email %></p>

    <p><label for="order_phone_number">Phone
number</label></p>
    <p><%= text_field :order, :phone_number %></p>
  </fieldset>

  <fieldset>
    <legend>Shipping Address</legend>
    <p><label for="order_ship_to_first_name">First
name</label></p>
    <p><%= text_field :order, :ship_to_first_name %></p>

    <p><label for="order_ship_to_last_name">Last
name</label></p>
    <p><%= text_field :order, :ship_to_last_name %></p>

    <p><label
for="order_ship_to_address">Address</label></p>
    <p><%= text_field :order, :ship_to_address %></p>

    <p><label
for="order_ship_to_city">City</label></p>
    <p><%= text_field :order, :ship_to_city %></p>

    <p><label for="order_ship_to_postal_code">Postal/Zip
code</label></
p>
    <p><%= text_field :order, :ship_to_postal_code %></p>

    <p><label
for="order_ship_to_country">Country</label></p>
    <p>
    <select name="order[ship_to_country]"
id="order_ship_to_country">
      <option value="US">United States</option>
      <option value="CA">Canada</option>
    </select>
    </p>
  </fieldset>


  <p> <%= submit_tag "Place Order" %> </p>
</form>


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Jake Thompson

2007-Oct-18 13:35 UTC

head link

Re: cart configuration and sessions

While what you are asking is about 20 questions, I will answer this.  The
functionality you are looking for with your shopping cart would really
require you to persist the card and items as a database table.  Then write
logic to save it when things are added/removed and to recall it from the DB
when a use logs in.  A session is not the right place for this type of
functionality.  The problem with long running carts, is that if you change
the price on something you may have a persisted cart item that has a
differnet price, so you need to decide if you persist the price when the
user adds items to the cart, or you keep it linked to the product that may
change over time.

-Jake

On 10/18/07, elle <waznelle-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:>
>
> Hi,
>
> I guess as many people, I am very new to Rails. I used a book to
> create a shopping cart and then modified the code to try and fit it to
> my project''s requirements. I have been trying figure this out for
the
> last week and starting to get really discouraged about the prospects
> of solving this. I know what needs to be done but I''m at a loss
for
> how to achieve it. So, I wanted to ask, for help. Please please
> please.
>
> Background:
> I have the following classes: customer, product, cart, cart_items,
> order, order_items
> A customer needs to login to even see the "Add to cart" links --
so
> the same goes for viewing cart and checkout. (which is achieved).
> Things I have trouble with:
> 1) The sessions are stored in the db. Right now, customer session and
> cart session are separate. I need to assoociate them together. So,
> when a customer loggs out and a new customer logs in, they have
> different carts. If the session can remember the cart items, if the
> same customer logs in again, that would be great. The customer id will
> also need to be stored in the orders tables as well.
> 2) I suddently have trouble even trying to add an item to the cart.
> 3) I need to figure out a way to update the quantity of items
> (products) in the cart.
> 4) And lastly, my checkout page doesn''t come up suddenly as well
>
> Please can anyone have a look and help me solve this?
> Any help will be so much appreciated,
> Thanks,
> Elle
>
> -------------------------------------------
> MODELS
> customer.rb:
>
> class Customer < ActiveRecord::Base
>   has_many :orders,
>            :dependent => true,
>            :order => "created_at ASC"
>   has_many :carts
>
>   validates_length_of       :name, :within => 3..40
>   validates_uniqueness_of   :name
>   validates_length_of       :password, :within => 4..40, :if
> => :password_required?
>
>   def open_orders
>     orders.find(:all, :conditions => "status =
''open''")
>   end
>
>   def orders_history
>     orders.find(:all, :conditions => "status =
''closed''")
>   end
>
>   def password=(value)
>     write_attribute("password", Digest::SHA1.hexdigest(value))
>   end
>
>   def self.authenticate(name,password)
>     find(:first, :conditions => ["name = ? and password =
?",name,
> Digest::SHA1.hexdigest(password)])
>   end
>
>   def self.orders
>     current_customer = Customer.find(param[:id])
>     orders = current_customer.orders
>   end
>
>   def self.carts
>     current_customer = Customer.find(param[:id])
>     orders = current_customer.carts
>   end
>
> end
>
> ------------------------------
> cart.rb:
>
> class Cart < ActiveRecord::Base
>   has_many :cart_items
>   has_many :products, :through => :cart_items
>   belongs_to  :customer
>
>   def total
>     cart_items.inject(0) {|sum, n| n.price * n.amount + sum}
>   end
>
>   def add(product_id)
>     items = cart_items.find_all_by_product_id(product_id)
>     product = Product.find(product_id)
>     if items.size < 1
>       ci = cart_items.create(:product_id => product_id,
>                              :amount => 1,
>                              :price => product.price)
>     else
>       ci = items.first
>       ci.update_attribute(:amount, ci.amount + 1)
>     end
>     ci
>   end
>
>   def remove(product_id)
>     ci = cart_items.find_by_product_id(product_id)
>
>     if ci.amount > 1
>       ci.update_attribute(:amount, ci.amount - 1)
>     else
>       CartItem.destroy(ci.id)
>     end
>     return ci
>   end
>
>   def update(product_id)
>     items = cart_items.find_all_by_product_id(product_id)
>     product = Product.find(product_id)
>     ci = cart_items
>     ci.update_attribute(:amount, ci.amount + 1)
>
>   end
>
> end
>
> -------------------------------
> CONTROLLER
> cart_controller.rb:
>
> class CartController < ApplicationController
>   before_filter :initialize_cart
>   before_filter :authorize,    :except => ["login"]
>
>   def authorize
>     return true if @c
>     flash[:notice] = "To place your order please login"
>     redirect_to :controller => "catalog"
>   end
>
>   def login
>     # examine the form data for "name" and "password"
>     pw,name = params[:customer].values_at(*%w{password name})
>     # Retrieve the customer record for the name and store it in a
> variable ''c''
>     c = Customer.find_by_name(name)
>     # if such record exists, and it''s password matches the
password
> from the form
>     if c && Digest::SHA1.hexdigest(pw) == c.password
>       # start a session with the customer id
>       session[:customer] = c.id
>       @cart = Cart.create
>       session[:customer]
>
>         if @cart.products.empty?
>            redirect_to :controller => "catalog"
>         else
>
>         redirect_to :action => "view_cart"
>         end
>     else
>       # otherwise report an error
>       flash[:notice] = "Invalid Login"
>       redirect_to :controller => "catalog"
>     end
>   end
>
>   def logout
>     session[:customer] = nil
>     redirect_to :controller => "catalog"
>   end
>
>   def index
>   end
>
>   def add
>     product = Product.find(params[:id])
>     if request.post?
>       @item = @cart.add(params[:id])
>       flash[:notice] = "Added
<em>#{@item.product.title}</em> to
> cart."
>       redirect_to :controller => "catalog"
>     else
>       render
>     end
>   end
>
>   def update
>     @product = Product.find(params[:id])
>     if request.post?
>       @item = @cart.update_attributes(params[:cart])
>       flash[:notice] = "Updated
<em>#{@item.product.title}</em>''s
> quantity."
>       redirect_to :action => "view_cart" and return if
@cart.save
>     else
>       render
>     end
>   end
>
>   def remove
>     @product = Product.find(params[:id])
>     if request.post?
>       @item = @cart.remove(params[:id])
>       flash[:notice] = "Removed
<em>#{@item.product.title}</em>"
>       redirect_to :action => "view_cart"
>     else
>       render
>     end
>   end
>
>   def clear
>     if request.post?
>       @cart.cart_items.destroy_all
>       flash[:notice] = "Cleared the cart"
>       redirect_to :controller => "catalog"
>     else
>       render
>     end
>   end
>
>   def view_cart
>     @page_title = "Shopping Cart for #{@c.name}"
>     @order = Order.new
>     if @cart.empty?
>       flash[:notice] = "Your shopping cart is empty! Please add
> something to it before proceeding to checkout."
>       redirect_to :controller => ''catalog''
>     end
>   end
>
>   def checkout
>     @page_title = "Checkout"
>     @order = Order.new(params[:order])
>     @order.customer_ip = request.remote_ip
>     @order.customer_id = @session[''customer'']
>     populate_order
>
>     if @order.save
>       if @order.process
>         flash[:notice] = ''Your order has been submitted, and will
be
> processed immediately.''
>         session[:order_id] = @order.id
>         # Empty the cart
>         @cart.cart_items.destroy_all
>         redirect_to :action => ''thank_you''
>       else
>         flash[:notice] = "Error while placing order.
> ''#{@order.error_message}''"
>         render :action => ''view_cart''
>       end
>     else
>       render :action => ''view_cart''
>     end
>   end
>
>   def thank_you
>     @page_title = ''Thank You!''
>   end
>
>
>   def populate_order
>     for cart_item in @cart.cart_items
>       order_item = OrderItem.new(
>         :product_id => cart_item.product_id,
>         :price => cart_item.price,
>         :amount => cart_item.amount
>       )
>       @order.order_items << order_item
>     end
>   end
>
> end
>
> ------------------------------------------
> VIEWS
> partial for cart item: _item.rhtml:
>
> <tr>
> <td><%=h item.product.sku %></td>
> <td><%= link_to item.product.title, :action =>
"show",
>       :controller => "catalog", :id => item.product.id
%></td>
> <td><%= pluralize(item.amount, "pc", "pcs")
%></td>
> <td>$<%= two_dec(item.price * item.amount) %></td>
>
> <td><%= form_tag :controller => "cart", :action =>
"update", :id =>
> item.product, :with => "new_qty" %>
> <%= text_field_tag "new_qty", "", "size"
=> 4 %>
> <input type="Submit", value="Update"/>
> <%= end_form_tag %>
> </td>
> <td><%= button_to "x", :controller =>
"cart", :action => "remove", :id
> => item.product %></td>
> </tr>
>
> -------------------------------------------------
> checkout.rhtml:
>
> <%= error_messages_for ''order'' %>
> <p><em>Your order&#8217;s total is: <%=h @cart.total
%></em></p>
> <form method="post" id="checkout"
action="<%= url_for :action
> => :checkout %>">
>   <fieldset>
>     <legend>Contact Information</legend>
>     <p><label
for="order_email">Email</label></p>
>     <p><%= text_field :order, :email %></p>
>
>     <p><label for="order_phone_number">Phone
number</label></p>
>     <p><%= text_field :order, :phone_number %></p>
>   </fieldset>
>
>   <fieldset>
>     <legend>Shipping Address</legend>
>     <p><label for="order_ship_to_first_name">First
name</label></p>
>     <p><%= text_field :order, :ship_to_first_name %></p>
>
>     <p><label for="order_ship_to_last_name">Last
name</label></p>
>     <p><%= text_field :order, :ship_to_last_name %></p>
>
>     <p><label
for="order_ship_to_address">Address</label></p>
>     <p><%= text_field :order, :ship_to_address %></p>
>
>     <p><label
for="order_ship_to_city">City</label></p>
>     <p><%= text_field :order, :ship_to_city %></p>
>
>     <p><label
for="order_ship_to_postal_code">Postal/Zip code</label></
> p>
>     <p><%= text_field :order, :ship_to_postal_code %></p>
>
>     <p><label
for="order_ship_to_country">Country</label></p>
>     <p>
>     <select name="order[ship_to_country]"
id="order_ship_to_country">
>       <option value="US">United States</option>
>       <option value="CA">Canada</option>
>     </select>
>     </p>
>   </fieldset>
>
>
>   <p> <%= submit_tag "Place Order" %> </p>
> </form>
>
>
> >
>
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Rails - Oct 2007 - cart configuration and sessions

cart configuration and sessions

Re: cart configuration and sessions