public async Task <List <BookPriceObject> > GetBookPrices(string title)
{
string bookIsbn;
try
{
bookIsbn = Isbn.GetBookIsbn(title);
}
catch (ArgumentNullException ex)
{
throw new ApplicationException($"Could not find ISBN for title: {title}", ex);
}
catch (NullReferenceException ex)
{
throw new ApplicationException($"Could not find ISBN for title: {title}", ex);
}
var prices = new List <BookPriceObject>();
foreach (var store in bookStores)
{
var bookData = await this.GetBookData(store, bookIsbn);
if (bookData != null)
{
prices.Add(bookData.Value);
}
}
return(prices);
}
public static string GetBookIsbn(string title)
{
HttpResponseMessage isbnResposne;
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.Add("User-Agent", "User-Agent-Here");
isbnResposne = client.GetAsync(Isbn.SearchUri + title).Result;
}
var htmlDocument = new HtmlDocument();
htmlDocument.LoadHtml(isbnResposne.Content.ReadAsStringAsync().Result);
var nodeWithValue = htmlDocument.DocumentNode.SelectNodes(Isbn.XPath)?.FirstOrDefault();
return(Isbn.GetValueFromHtmlNode(nodeWithValue));
}
