Class: GoogleCheckout::Cart

Inherits:
Command
  • Object
show all
Includes:
GoogleCheckout
Defined in:
lib/google-checkout/cart.rb

Overview

This class represents a cart for Google Checkout. After initializing it with a merchant_id and merchant_key, you add items via add_item, and can then get xml via to_xml, or html code for a form that provides a checkout button via checkout_button.

Example:

item = {
         :name => 'A Quarter',
         :description => 'One shiny quarter.',
         :price => 0.25
       }
@cart = GoogleCheckout::Cart.new(merchant_id, merchant_key, item)
@cart.add_item(:name => "Pancakes",
               :description => "Flapjacks by mail."
               :price => 0.50,
               :quantity => 10,
               "merchant-item-id" => '2938292839')

Then in your view:

Checkout here! <%= @cart.checkout_button %>

This object is also useful for getting back a url to the image for a Google Checkout button. You can use this image in forms that submit back to your own server for further processing via Google Checkout’s level 2 XML API.

Constant Summary collapse

SANDBOX_CHECKOUT_URL = 
"https://sandbox.google.com/checkout/cws/v2/Merchant/%s/checkout"
PRODUCTION_CHECKOUT_URL = 
"https://checkout.google.com/cws/v2/Merchant/%s/checkout"
DefaultButtonOpts =

The default options for drawing in the button that are filled in when checkout_button or button_url is called.

{
  :size => :medium,
  :style => 'white',
  :variant => 'text',
  :loc => 'en_US',
  :buy_or_checkout => nil,
}

Constants included from GoogleCheckout

ButtonSizes, VERSION

Constants inherited from Command

GoogleCheckout::Command::PRODUCTION_REQUEST_URL, GoogleCheckout::Command::SANDBOX_REQUEST_URL

Instance Attribute Summary collapse

Attributes inherited from Command

#merchant_id, #merchant_key

Instance Method Summary collapse

Methods included from GoogleCheckout

production?, sandbox?, use_production, use_sandbox

Methods inherited from Command

#post, #url, x509_store

Constructor Details

#initialize(merchant_id, merchant_key, *items) ⇒ Cart

You need to supply, as strings, the merchant_id and merchant_key used to identify your store to Google. You may optionally supply one or more items to put inside the cart.



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# File 'lib/google-checkout/cart.rb', line 83

def initialize(merchant_id, merchant_key, *items)
  super(merchant_id, merchant_key)
  @contents = []
  @merchant_private_data = {}
  items.each { |i| add_item i }
end

Instance Attribute Details

#continue_shopping_url ⇒ Object

Returns the value of attribute continue_shopping_url.



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# File 'lib/google-checkout/cart.rb', line 68

def continue_shopping_url
  @continue_shopping_url
end

#edit_cart_url ⇒ Object

Returns the value of attribute edit_cart_url.



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# File 'lib/google-checkout/cart.rb', line 67

def edit_cart_url
  @edit_cart_url
end

#merchant_private_data ⇒ Object

You can provide extra data that will be sent to Google and returned with the NewOrderNotification.

This should be a Hash and will be turned into XML with proper escapes.

Beware using symbols as values. They may be set as sub-keys instead of values, so use a String or other datatype.



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# File 'lib/google-checkout/cart.rb', line 65

def merchant_private_data
  @merchant_private_data
end

Instance Method Details

#add_item(item) ⇒ Object

This method puts items in the cart. item may be a hash, or have a method named to_google_product that returns a hash with the required values.

  • name

  • description (a brief description as it will appear on the bill)

  • price

You may fill in some optional values as well:

  • quantity (defaults to 1)

  • currency (defaults to ‘USD’)



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# File 'lib/google-checkout/cart.rb', line 138

def add_item(item)
  @xml = nil
  if item.respond_to? :to_google_product
    item = item.to_google_product
  end

  # We need to check that the necessary keys are in the hash,
  # Otherwise the error will happen in the middle of to_xml,
  # and the bug will be harder to track.
  missing_keys = [ :name, :description, :price ].select { |key|
    !item.include? key
  }

  unless missing_keys.empty?
    raise ArgumentError,
    "Required keys missing: #{missing_keys.inspect}"
  end

  @contents << { :quantity => 1, :currency => 'USD' }.merge(item)
  item
end

#button_url(opts = {}) ⇒ Object

Given a set of options for the button, button_url returns the URL for the button image. The options are the same as those specified on checkout.google.com/seller/checkout_buttons.html , with a couple of extra options for convenience. Rather than specifying the width and height manually, you may specify :size to be one of :small, :medium, or :large, and that you may set :buy_or_checkout to :buy_now or :checkout to get a ‘Buy Now’ button versus a ‘Checkout’ button. If you don’t specify :buy_or_checkout, the Cart will try to guess based on if the cart has more than one item in it. Whatever you don’t pass will be filled in with the defaults from DefaultButtonOpts.

http://checkout.google.com/buttons/checkout.gif
http://sandbox.google.com/checkout/buttons/checkout.gif



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# File 'lib/google-checkout/cart.rb', line 329

def button_url(opts = {})
  opts = DefaultButtonOpts.merge opts
  opts[:buy_or_checkout] ||= @contents.size > 1 ? :checkout : :buy_now
  opts.merge! ButtonSizes[opts[:buy_or_checkout]][opts[:size]]
  bname = opts[:buy_or_checkout] == :buy_now ? 'buy.gif' : 'checkout.gif'
  opts.delete :size
  opts.delete :buy_or_checkout
  opts[:merchant_id] = @merchant_id

  path = opts.map { |k,v| "#{k}=#{v}" }.join('&')

  # HACK Sandbox graphics are in the checkout subdirectory
  subdir = ""
  if GoogleCheckout.sandbox? && bname == "checkout.gif"
    subdir = "checkout/"
  end

  # TODO Use /checkout/buttons/checkout.gif if in sandbox.
  "http://#{submit_domain}/#{ subdir }buttons/#{bname}?#{path}"
end

#checkout_button(button_opts = {}) ⇒ Object

Returns HTML for a checkout form for buying all the items in the cart.



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# File 'lib/google-checkout/cart.rb', line 284

def checkout_button(button_opts = {})
  @xml or to_xml
  burl = button_url(button_opts)
  html = Builder::XmlMarkup.new(:indent => 2)
  html.form({
              :action => submit_url,
              :style => 'border: 0;',
              :id => 'BB_BuyButtonForm',
              :method => 'post',
              :name => 'BB_BuyButtonForm'
            }) do
    html.input({
                 :name => 'cart',
                 :type => 'hidden',
                 :value => Base64.encode64(@xml).gsub("\n", '')
               })
    html.input({
                 :name => 'signature',
                 :type => 'hidden',
                 :value => Base64.encode64(signature).gsub("\n", '')
               })
    html.input({
                 :alt => 'Google Checkout',
                 :style => "width: auto;",
                 :src => button_url(button_opts),
                 :type => 'image'
               })
  end
end

#currency ⇒ Object

Returns the currency for the cart. Mixing currency not allowed; this library can’t convert between currencies.



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# File 'lib/google-checkout/cart.rb', line 263

def currency
  # Mixing currency not allowed; this
  # library can't convert between
  # currencies.
  @currency ||=
    (@contents.map { |item|
       item.currency
     }.uniq.first rescue nil) ||
    'USD'
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/google-checkout/cart.rb', line 109

def empty?
  @contents.empty?
end

#flat_rate_shipping(frs_options) ⇒ Object

This method sets the flat rate shipping for the entire cart. If set, it will over ride the per product flat rate shipping. frs_options should be a hash containing the following options:

  • price

You may fill an some optional values as well:

  • currency (defaults to ‘USD’)



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# File 'lib/google-checkout/cart.rb', line 97

def flat_rate_shipping(frs_options)
  # We need to check that the necessary keys are in the hash,
  # Otherwise the error will happen in the middle of to_xml,
  # and the bug will be harder to track.
  unless frs_options.include? :price
    raise ArgumentError,
    "Required keys missing: :price"
  end

  @flat_rate_shipping = {:currency => 'USD'}.merge(frs_options)
end

#shipping_cost ⇒ Object

Returns the shipping cost for the contents of the cart.



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# File 'lib/google-checkout/cart.rb', line 254

def shipping_cost
  currency = 'USD'
  shipping = @contents.inject(0) { |total,item|
    total + item[:regular_shipping].to_i
  }.to_s
end

#shipping_cost_xml ⇒ Object

Generates the XML for the shipping cost, conditional on



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# File 'lib/google-checkout/cart.rb', line 240

def shipping_cost_xml
  xml = Builder::XmlMarkup.new
  if @flat_rate_shipping
    xml.price(:currency => currency) {
      xml.text! @flat_rate_shipping[:price].to_s
    }
  else
    xml.price(:currency => @currency) {
      xml.text! shipping_cost.to_s
    }
  end
end

#signature ⇒ Object

Returns the signature for the cart XML.



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# File 'lib/google-checkout/cart.rb', line 275

def signature
  @xml or to_xml

  digest  = OpenSSL::Digest::Digest.new('sha1')
  OpenSSL::HMAC.digest(digest, @merchant_key, @xml)
end

#size ⇒ Object

Number of items in the cart.



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# File 'lib/google-checkout/cart.rb', line 114

def size
  @contents.size
end

#submit_domain ⇒ Object 



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# File 'lib/google-checkout/cart.rb', line 118

def submit_domain
  (GoogleCheckout.production? ? 'checkout' : 'sandbox') + ".google.com"
end

#submit_url ⇒ Object

The Google Checkout form submission url.



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# File 'lib/google-checkout/cart.rb', line 125

def submit_url
  GoogleCheckout.sandbox? ? (SANDBOX_CHECKOUT_URL % @merchant_id) : (PRODUCTION_CHECKOUT_URL % @merchant_id)
end

#to_xml ⇒ Object

This is the important method; it generatest the XML call. It’s fairly lengthy, but trivial. It follows the docs at code.google.com/apis/checkout/developer/index.html#checkout_api

It returns the raw XML string, not encoded.

Raises:

  • (RuntimeError) 


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# File 'lib/google-checkout/cart.rb', line 165

def to_xml
  raise RuntimeError, "Empty cart" if self.empty?

  xml = Builder::XmlMarkup.new
  xml.instruct!
  @xml = xml.tag!('checkout-shopping-cart', :xmlns => "http://checkout.google.com/schema/2") {
    xml.tag!("shopping-cart") {
      xml.items {
        @contents.each { |item|
          xml.item {
            if item.key?(:item_id)
              xml.tag!('merchant-item-id', item[:item_id])
            end
            xml.tag!('item-name') {
              xml.text! item[:name].to_s
            }
            xml.tag!('item-description') {
              xml.text! item[:description].to_s
            }
            xml.tag!('unit-price', :currency => (item[:currency] || 'USD')) {
              xml.text! item[:price].to_s
            }
            xml.quantity {
              xml.text! item[:quantity].to_s
            }
          }
        }
      }
      unless @merchant_private_data.empty?
        xml.tag!("merchant-private-data") {
          @merchant_private_data.each do |key, value|
            xml.tag!(key, value)
          end
        }
      end
    }
    xml.tag!('checkout-flow-support') {
      xml.tag!('merchant-checkout-flow-support') {
        xml.tag!('edit-cart-url', @edit_cart_url) if @edit_cart_url
        xml.tag!('continue-shopping-url', @continue_shopping_url) if @continue_shopping_url

        xml.tag!("request-buyer-phone-number", false)

        # TODO tax-tables
        xml.tag!("tax-tables") {
          xml.tag!("default-tax-table") {
            xml.tag!("tax-rules") {
              xml.tag!("default-tax-rule") {
                xml.tag!("shipping-taxed", false)
                xml.tag!("rate", "0.00")
                xml.tag!("tax-area") {
                  xml.tag!("world-area")
                }
              }
            }
          }
        }

        # TODO Shipping calculations
        #      These are currently hard-coded for PeepCode.
        #      Does anyone care to send a patch to enhance
        #      this for more flexibility?
        xml.tag!('shipping-methods') {
          xml.tag!('pickup', :name =>'Digital Download') {
            xml.tag!('price', "0.00", :currency => currency)
          }
        }
      }
    }
  }
  @xml.dup
end