private static StockQuote BuildQuote(XPathNavigator quoteNavigator)
{
if (!quoteNavigator.MoveToAttribute("Symbol", string.Empty))
{
// error
}
string symbol = quoteNavigator.Value;
double last = 0d, volume = 0d, change = 0d, percentChange = 0d;
string lastTimeString;
DateTime lastUpdate = DateTime.Today;
quoteNavigator.MoveToParent();
if (quoteNavigator.MoveToChild("Last", string.Empty))
{
last = quoteNavigator.ValueAsDouble;
}
if (quoteNavigator.MoveToNext("LastTime", string.Empty))
{
lastTimeString = quoteNavigator.Value;
DateTime.TryParseExact(
lastTimeString,
"h:mm tt",
CultureInfo.InvariantCulture,
DateTimeStyles.None,
out lastUpdate);
}
if (quoteNavigator.MoveToNext("Volume", string.Empty))
{
string volumeText = quoteNavigator.Value;
if (!double.TryParse(volumeText, NumberStyles.Any, CultureInfo.InvariantCulture, out volume))
{
volume = 0d;
}
}
if (quoteNavigator.MoveToNext("Change", string.Empty))
{
change = quoteNavigator.ValueAsDouble;
}
if (quoteNavigator.MoveToNext("PercentChange", string.Empty))
{
percentChange = quoteNavigator.ValueAsDouble / 100;
}
StockQuote quote = new StockQuote(symbol, volume, last, lastUpdate, change, percentChange);
return(quote);
}
public IDictionary <string, StockQuote> GetQuotes(IEnumerable <string> symbols)
{
Dictionary <string, StockQuote> quotes = new Dictionary <string, StockQuote>();
StringBuilder flattenedSymbols = new StringBuilder();
foreach (string symbol in symbols)
{
quotes.Add(symbol, null);
flattenedSymbols.Append(symbol);
flattenedSymbols.Append(' ');
}
logger.Log("Retrieving quotes for " + flattenedSymbols, TraceEventType.Information);
string payload = null;
try
{
payload = implementation.DDSQuery(flattenedSymbols.ToString(), null, null);
}
catch (Exception e)
{
string message = "Error invoking service: " + e.Message;
logger.Log(message, TraceEventType.Error);
throw new StockQuoteServiceException(message, e);
}
logger.Log("Received result for " + flattenedSymbols, TraceEventType.Information);
using (TextReader payloadReader = new StringReader(payload))
{
XPathDocument document = null;
try
{
document = new XPathDocument(payloadReader);
}
catch (Exception e)
{
string message = "Error parsing XML payload: " + e.Message;
logger.Log(message, TraceEventType.Error);
throw new StockQuoteServiceException(message, e);
}
logger.Log("Parsed result for " + flattenedSymbols, TraceEventType.Information);
XPathNavigator navigator = document.CreateNavigator();
foreach (XPathNavigator quoteNavigator in navigator.Select("/StockData/Quotes/Quote"))
{
StockQuote quote = BuildQuote(quoteNavigator);
if (quotes.ContainsKey(quote.Symbol))
{
quotes[quote.Symbol] = quote;
}
else
{
logger.Log("Unexpected symbol '" + quote.Symbol + "'", TraceEventType.Warning);
}
}
}
return(quotes);
}
private void SaveQuote(StockQuote updatedQuote)
{
try
{
this.repository.Save(updatedQuote);
}
catch (RepositoryException e)
{
this.logger.Log(
string.Format(
"Error saving the updated quote for '{0}': {1}",
updatedQuote.Symbol,
e.Message),
TraceEventType.Warning);
}
}