public IAsyncResult BeginQuery(string query, string entity, AsyncCallback callback, object state)
{
string uri = ConstructQueryUri(query, entity);
WebRequest req = WebRequest.Create(uri);
SupermarketResult smResult = new SupermarketResult(state);
smResult.InnerResult = req.BeginGetResponse(
(result) =>
{
if (callback != null)
callback(smResult);
},
req);
return smResult;
}
public IAsyncResult BeginQuery(string query, string entity, AsyncCallback callback, object state)
{
string uri = ConstructQueryUri(query, entity);
WebRequest req = WebRequest.Create(uri);
SupermarketResult smResult = new SupermarketResult(state);
smResult.InnerResult = req.BeginGetResponse(
(result) =>
{
if (callback != null)
{
callback(smResult);
}
},
req);
return(smResult);
}
public IEnumerable <SupermarketQueryResult> EndQuery(IAsyncResult result)
{
if (!result.IsCompleted)
{
result.AsyncWaitHandle.WaitOne();
}
SupermarketResult supermarketResult = result as SupermarketResult;
if (supermarketResult == null)
{
throw new ArgumentException(InvalidAsyncResult, "result");
}
WebRequest req = supermarketResult.InnerResult.AsyncState as WebRequest;
if (req == null)
{
throw new ArgumentException(InvalidAsyncResult, "result");
}
XElement root;
XmlNamespaceManager nsmgr;
using (WebResponse resp = req.EndGetResponse(supermarketResult.InnerResult))
using (Stream stream = resp.GetResponseStream())
{
XmlReader reader = XmlReader.Create(stream);
root = XElement.Load(reader);
nsmgr = new XmlNamespaceManager(reader.NameTable);
}
// Extend the namespace manager with some prefixes needed for processing results.
nsmgr.AddNamespace(SupermarketPrefix, SupermarketNS);
/* TODO: add error handling
* var errors = root.XPathSelectElements(SearchErrorXPath, nsmgr);
* if (errors.Count() > 0)
* // TODO: Probably want to report these somewhere.
* throw new ApplicationException("Search service errors were returned.");
*/
var searchProductResults = root.XPathSelectElements(SearchProductResultXPath, nsmgr);
foreach (var webResult in searchProductResults)
{
var itemName = webResult.XPathSelectElement(SearchProductResultItemname, nsmgr);
var description = webResult.XPathSelectElement(SearchProductResultItemDescription, nsmgr);
var category = webResult.XPathSelectElement(SearchProductResultItemCategory, nsmgr);
var id = webResult.XPathSelectElement(SearchProductResultItemID, nsmgr);
var image = webResult.XPathSelectElement(SearchProductResultItemImage, nsmgr);
var aisle = webResult.XPathSelectElement(SearchProductResultAisleNumber, nsmgr);
var retval = new SupermarketQueryResult();
retval[SupermarketQueryResult.Name] = itemName != null ? itemName.Value : null;
retval[SupermarketQueryResult.Description] = description != null ? description.Value : null;
retval[SupermarketQueryResult.Category] = category != null ? category.Value : null;
retval[SupermarketQueryResult.ID] = id != null ? id.Value : null;
retval[SupermarketQueryResult.Image] = image != null ? image.Value : null;
retval[SupermarketQueryResult.Aisle] = aisle != null ? aisle.Value : null;
yield return(retval);
}
}