public AffiliateProductDto Get()
{
// Input is passed in the query string. Interface might change eventually.
// For now lets just get a keyword from query string and use that.
// Do check the keyword though because our control will pass it otherwise what's the point.
// Do input validation first because it is less expensive
if (!Request.Query.ContainsKey(QUERY_STRING_PARAMETER_KEYWORD))
{
return(null);
}
var keyword = Request.Query[QUERY_STRING_PARAMETER_KEYWORD][0];
if (string.IsNullOrEmpty(keyword) || string.IsNullOrWhiteSpace(keyword))
{
return(null);
}
string category = null;
if (Request.Query.ContainsKey(QUERY_STRING_PARAMETER_CATEGORY))
{
category = Request.Query[QUERY_STRING_PARAMETER_CATEGORY][0];
}
// Check if caller gave us security header.
// This might throw exception if there was a header but invalid. But if someone is just messing with us we will return null.
// Null in this case because we will also check that in react.
var product = new AffiliateProductDto();
if (!ParseAntiForgeryHeader(_antiforgery, product, HttpContext))
{
return(product);
}
// Form the parameters object. This will get smarter then just keyword eventually.
var parameters = new ProductSearchParameters()
{
Keyword = keyword, Category = category
};
// Call the service
product = _productService.FindProduct(parameters);
// this may be null but we are not going to do anything here no pint really. Just let the client side deal with results.
return(product);
}
/// <summary>
/// Add product to cache.
/// </summary>
/// <param name="productKey"></param>
/// <param name="product"></param>
public void CacheProduct(string productKey, AffiliateProductDto product)
{
// This is not intended to be called from the outside and is public only for tests and transparency.
// This is supposed to be called only from this class therefor we can throw an expection.
if (string.IsNullOrEmpty(productKey) || string.IsNullOrWhiteSpace(productKey))
{
throw new Exception("AmazonProductService CacheProduct function is called with empty productKey.");
}
if (_cacheManager == null)
{
throw new Exception("AmazonProductService CacheProduct function is called with empty cache manager.");
}
// Re-Check cache in case product is already added while we were waiting for amazon.
var data = _cacheManager.Get(productKey);
// return if found
if (data != null)
{
return;
}
// Add to cache
_cacheManager.Add(productKey, product, DEFAULT_PRODUCT_EXPIRATION_SECONDS);
}
/// <summary>
/// Parses amazon product details into a generic dto object from the xml node retuned by amazon rest call.
/// </summary>
/// <param name="productXmlNode"></param>
/// <returns></returns>
/// <remarks>
/// Check the myxml.xml file for xml example.
/// I specifically decided not to parse into an object. Too much trouble with serialization/deserialization.
/// Underneath it is probably parsing each node anyway when converting to object.
/// </remarks>
public AffiliateProductDto ParseProduct(XmlNode productXmlNode, XmlNamespaceManager nsmgr, string namespacePrefix)
{
// This starts in Item node
// check input
if (productXmlNode == null)
{
return(null);
}
var product = new AffiliateProductDto()
{
Merchant = "Amazon"
};
product.DetailPageURL = GetChildNodeValue(productXmlNode, "DetailPageURL");
product.MerchantProductId = GetChildNodeValue(productXmlNode, "ASIN");
var attributesNode = GetChildNode(productXmlNode, "ItemAttributes");
product.Title = GetChildNodeValue(attributesNode, "Title");
// Parse price
var listPriceNode = GetChildNode(attributesNode, "ListPrice");
// Parse list price node if there. Search for ItemAttributes/ListPrice/FormattedPrice
if (listPriceNode != null)
{
product.FormattedPrice = GetChildNodeValue(listPriceNode, "FormattedPrice");
}
else
{
// Search for OfferSummary/LowestNewPrice/FormattedPrice
var offerSummaryNode = GetChildNode(productXmlNode, "OfferSummary");
if (offerSummaryNode != null)
{
var lowestNewPriceNode = GetChildNode(offerSummaryNode, "LowestNewPrice");
if (lowestNewPriceNode != null)
{
product.FormattedPrice = GetChildNodeValue(lowestNewPriceNode, "FormattedPrice");
}
}
}
// Parse description
// Search for OfferSummary/LowestNewPrice/FormattedPrice
var editorialReviewsNode = GetChildNode(productXmlNode, "EditorialReviews");
if (editorialReviewsNode != null)
{
foreach (XmlNode editorialReviewNode in editorialReviewsNode.ChildNodes)
{
if (editorialReviewNode.Name == "EditorialReview")
{
var source = GetChildNodeValue(editorialReviewNode, "Source");
var content = GetChildNodeValue(editorialReviewNode, "Content");
if (!product.Descriptions.ContainsKey(source))
{
product.Descriptions.Add(source, content);
}
}
}
}
// Let's get all images because we need to pick some decent size.
// I will let the function to add of not add image
var images = new List <ProductImage>();
// see if medium image is good enough
ParseAndAddImage(images, productXmlNode, "MediumImage");
// see if large image is good enough
ParseAndAddImage(images, productXmlNode, "LargeImage");
// see if small image is good enough
ParseAndAddImage(images, productXmlNode, "SmallImage");
if (images.Count > 0)
{
product.MiddleImageURL = images[0].Url;
product.MiddleImageWidth = images[0].Width;
product.MiddleImageHeight = images[0].Height;
}
return(product);
}
