public void ProcessPriceUpdates(string productCode)
{
// get the necessary dependencies
IWebPageEngine pageEngine = EngineLocator.CreateEngine <IWebPageEngine>();
IProductParserEngine priceEngine = EngineLocator.CreateEngine <IProductParserEngine>();
IProductAccessor productAccessor = AccessorLocator.CreateAccessor <IProductAccessor>();
IEmailAccessor emailAccessor = AccessorLocator.CreateAccessor <IEmailAccessor>();
// build the url
string url = pageEngine.BuildUrl(productCode);
// get the page contents
string contents = pageEngine.GetWebPageContents(url);
// get the stored product information
var product = productAccessor.FindByCode(productCode);
// get the current price
decimal currentPrice = priceEngine.GetProductPrice(contents, productCode);
// if the current price is different from the price threshold then send an email
if (currentPrice > 0)
{
if (product.PriceThreshold != currentPrice)
{
emailAccessor.SendPriceNotice(product, currentPrice);
}
}
}
public decimal GetProductPrice(string productPageContents, string productCode)
{
var doc = new HtmlDocument();
doc.LoadHtml(productPageContents);
// get the correct XPath for the specific product
IProductConfigAccessor productConfigAccessor = AccessorLocator.CreateAccessor <IProductConfigAccessor>();
string xpath = productConfigAccessor.GetXPath(productCode);
HtmlNode priceNode = doc.DocumentNode.SelectSingleNode(xpath);
decimal price = -1.00m;
if (priceNode != null)
{
decimal.TryParse(WebUtility.HtmlDecode(priceNode.InnerText.Trim().Replace("$", "")), out price);
}
return(price);
}
