Show the total cost of an Amazon Wish List.

amazon_wish_list.js

//
// This script shows the total cost of an Amazon Wish List.
//
// Usage:
//
//   1. Open an Amazon Wish List
//   2. Select the "Compact" option in the "View" drop-down
//   3. Click the "GO" button
//   4. Copy and paste the code below in the browser console
//   5. Press Enter
//
// The MIT License (MIT)
//
// Copyright (c) 2013 Murilo Pereira <murilo@murilopereira.com>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

(function($) {
  function zip() {
    var arrays = $.makeArray(arguments);

    var length = Math.max.apply(Math, $.map(arrays, function(array) {
      return(array.length);
    }));

    var zipped = Array(length);

    for (var i = 0; i < length; i++) {
      zipped[i] = $.map(arrays, function(array) { return(array[i]); });
    }

    return(zipped);
  }

  this.Amazon = {};

  Amazon.Product = function(attributes) {
    this.name = attributes.name;
    this.price = attributes.price;
    this.quantity = attributes.quantity;
  };

  Amazon.Product.prototype = (function() {
    return({
      cost: function() {
        return(this.price * this.quantity);
      }
    });
  })();

  Amazon.WishList = function() {
  };

  Amazon.WishList.prototype = (function() {
    var $baseSelector =
      $('tr .g-selected input').parents('label').parents('td').parents('tr');

    var $productNames      = $baseSelector.find('.g-title');
    var $productPrices     = $baseSelector.find('.g-price');
    var $productQuantities = $baseSelector.find('.g-requested input');

    function productsNames() {
      return($productNames.map(function(index, el) {
        return($(el).text().trim().replace(/\s+/g, ' '));
      }));
    }

    function productsPrices() {
      return($productPrices.map(function(index, el) {
        return(parseFloat($(el).text().trim().replace(/[^\d.]/g, '')) || 0.0);
      }));
    }

    function productsQuantities() {
      return($productQuantities.map(function(index, el) {
        return(parseInt($(el).val(), 10) || 0);
      }));
    }

    function productsAttributes() {
      return(zip(productsNames(), productsPrices(), productsQuantities()));
    }

    return({
      products: function() {
        return($.map(productsAttributes(), function(productAttributes) {
          return(new Amazon.Product({
            name: productAttributes[0],
            price: productAttributes[1],
            quantity: productAttributes[2]
          }));
        }));
      },

      cost: function() {
        return(this.products().reduce(function(totalCost, product) {
          return(totalCost + product.cost());
        }, 0));
      }
    });
  })();

  alert('Wish List total cost: ' + (new Amazon.WishList()).cost());
})(jQuery);