private void NextBarIconButton_Click(object sender, EventArgs e)
{
NewsPage currentContext = (NewsPage)((PivotItem)MainPivot.SelectedItem).DataContext;
nextPrevUrlStacks[MainPivot.SelectedIndex].Push(currentContext.NextURLPostfix);
FetchNews(MainPivot.SelectedIndex);
UpdateAppBarLabels();
}
void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
LoadingProgressBar.IsVisible = false;
if (e.Error != null && !e.Cancelled)
{
FlurryWP7SDK.Api.LogError("Error in client_DownloadStringCompleted when fetching news on Main Page", e.Error);
// Display the connection error text in the SystemTray for 2s
ShowConnectionError(true);
PerformActionWithDelay(() => ShowConnectionError(false), 2000);
}
else if (!e.Cancelled)
{
// Parse the news results on a background thread, and then update the UI
BackgroundWorker updateNewsWorker = new BackgroundWorker();
updateNewsWorker.DoWork += delegate(object s, DoWorkEventArgs args)
{
args.Result = HackerNewsParser.ParseNewsPage(e.Result);
};
updateNewsWorker.RunWorkerCompleted += delegate(object s, RunWorkerCompletedEventArgs args)
{
NewsPage newsPage = (NewsPage)args.Result;
int pivotIndx = (int)e.UserState;
PivotItem currentPivotItem = (PivotItem)MainPivot.Items[pivotIndx];
ListBox currentListBox = (ListBox)currentPivotItem.Content;
lastRefreshed[pivotIndx] = DateTime.Now;
currentPivotItem.DataContext = newsPage;
currentListBox.ItemsSource = null;
currentListBox.ItemsSource = newsPage.Items;
currentListBox.UpdateLayout();
currentListBox.ScrollIntoView(currentListBox.Items[0]);
UpdateAppBarLabels();
};
updateNewsWorker.RunWorkerAsync();
}
}
public static NewsPage ParseNewsPage(string htmlString)
{
HtmlDocument document = new HtmlDocument();
document.LoadHtml(htmlString);
// LINQ Query to obtain the news story title and URL on the front page
var titlesOnPage = from node in document.DocumentNode.Descendants()
where node.Name == "td" &&
node.Attributes["class"] != null &&
node.Attributes["class"].Value == "title" &&
node.FirstChild.Name == "a"
select node.FirstChild;
NewsPage newsPage = new NewsPage();
List <NewsItem> newsItemList = new List <NewsItem>();
foreach (HtmlNode n in titlesOnPage)
{
NewsItem i = new NewsItem();
try
{
i.Title = HttpUtility.HtmlDecode(n.InnerText.Trim());
i.Url = n.Attributes["href"].Value;
i.IsLocal = i.Url.StartsWith("item?");
if (i.Title == "More")
{
newsPage.NextURLPostfix = i.Url;
if (!newsPage.NextURLPostfix.StartsWith("/"))
{
newsPage.NextURLPostfix = "/" + newsPage.NextURLPostfix;
}
break;
}
}
catch (Exception exception)
{
FlurryWP7SDK.Api.LogError("Exception parsing news story title/url. Title = " + i.Title + "; URL = " + i.Url, exception);
}
newsItemList.Add(i);
}
// LINQ Query to obtain the Id, CommentCount, Points, PostedAgo, and PostedBy for each
// story on the front page
var storySubtextsOnPage = from node in document.DocumentNode.Descendants()
where node.Name == "td" &&
node.Attributes["class"] != null &&
node.Attributes["class"].Value == "subtext"
select node;
int cntr = 0;
foreach (HtmlNode n in storySubtextsOnPage)
{
NewsItem i = newsItemList[cntr];
try
{
if (n.ChildNodes.Count == 1)
{
// This is a job ad - all that is displayed is how long ago posted
i.Points = 0;
i.PostedAgo = n.ChildNodes[0].InnerText;
i.PostedBy = string.Empty;
i.CommentCount = 0;
i.Id = -1;
i.IsJobAd = true;
}
else
{
string pointsStr = n.ChildNodes[0].InnerText.Trim();
i.Points = int.Parse(pointsStr.Split()[0]);
i.PostedBy = n.ChildNodes[2].InnerText;
i.PostedAgo = n.ChildNodes[3].InnerText.Trim(new char[] { ' ', '|' });
string commentsStr = n.ChildNodes[4].InnerText.Trim();
if (commentsStr == "discuss")
{
i.CommentCount = 0;
}
else
{
i.CommentCount = int.Parse(commentsStr.Split()[0]);
}
string urlStr = n.ChildNodes[4].Attributes["href"].Value;
i.Id = int.Parse(urlStr.Substring(urlStr.IndexOf("=") + 1));
}
}
catch (Exception exception)
{
FlurryWP7SDK.Api.LogError("Exception parsing news story subtext. Title = " + i.Title + "; URL = " + i.Url, exception);
}
cntr++;
}
newsPage.Items = newsItemList;
return(newsPage);
}
