/// <summary>
/// Creates a list of the top ten products in a category, wraps those
/// product names and Amazon Urls in a Product object and appends the
/// Constants.AMAZON_TAG_IDENTIFIER onto the Url of the product link.
/// </summary>
/// <param name="category">the category id used to locate the list of
/// top ten products.</param>
/// <returns>a list of Product objects</returns>
/// <remarks>
/// IMPORTANT: the value indicated in Constants.AMAZON_TAG_IDENTIFIER
/// MUST be included in the DetailPageURL of every product.
/// </remarks>
public List<Product> GetTopTenProducts(Category category)
{
List<Product> ret = new List<Product>();
// create a list of request parameters
Dictionary<string, string> requestParameters = new Dictionary<string, string>();
requestParameters.Add("Service", "AWSECommerceService");
requestParameters.Add("Version", Constants.AMAZON_API_VERSION);
requestParameters.Add("Operation", "BrowseNodeLookup");
requestParameters.Add("BrowseNodeId", category.CategoryId);
requestParameters.Add("ResponseGroup", "TopSellers");
string signedUrl = Amazon.Sign(requestParameters);
XNamespace ns = Constants.AMAZON_DOCUMENT_NAMESPACE;
// contact Amazon retrieve the list of BrowseNodes as XML
var root = XElement.Load(signedUrl);
// get the list of all children under BrowseNodes/BrowseNode/Children/BrowseNode
var nodes = from node in root
.Element(ns + "BrowseNodes")
.Element(ns + "BrowseNode")
.Element(ns + "TopItemSet")
.Descendants(ns + "TopItem")
select new
{
Asin = node.Element(ns + "ASIN").Value,
Title = node.Element(ns + "Title").Value,
DetailPageURL = node.Element(ns + "DetailPageURL").Value
};
List<string> asins = new List<string>();
foreach (var node in nodes)
{
string url = GetAmazonUrlWithTag(node.DetailPageURL);
Product product =
new Product(node.Title,
new Uri(url),
node.Asin);
ret.Add(product);
asins.Add(product.Asin);
}
return ret;
}