partial void DeleteFeed(Feed instance);
partial void InsertFeed(Feed instance);
partial void UpdateFeed(Feed instance);
/// <summary>
/// Determines which articles will be placed into the featured section. Updates the stored featured articles.
/// </summary>
public static void UpdateFeatured()
{
Collection <Article> articles = new Collection <Article>();
int favConst = 10;
int shareConst = 30;
// Query the database for feeds with unread articles.
List <Feed> unreadFeeds = App.DataBaseUtility.QueryForUnreadFeeds();
int[] thresholds = new int[unreadFeeds.Count()];
// Calculate the threshold value for each of the feeds. Top threshold feeds are chosen.
for (int i = 0; i < unreadFeeds.Count(); i++)
{
// c.Skip(i).Take(1).Single() is essentially the equivalent of c.ElementAt(i).
// c.ElementAt(i) is not an allowed operation for QueriableItem c.
Feed feed = unreadFeeds[i];
// Give threshold a minimum value of 1 to allow it to work well with MaxIndex().
thresholds[i] = 1 + feed.ViewCount.Value + (feed.FavoritedCount.Value * favConst) +
(feed.SharedCount.Value * shareConst);
}
// Take the maximum 6 threshold indexes, which will be used to obtain the articles.
int[] maxThresIndexes = new int[6];
int articleCount = 0; // 6 articles are necessary for the Featured section.
int numOfFeeds = 0; // Number of feeds it takes to obtain 6 articles.
while (numOfFeeds < 6)
{
maxThresIndexes[numOfFeeds] = MaxIndex(thresholds);
// In case there are no more unread feeds:
if (maxThresIndexes[numOfFeeds] == -1)
{
break;
}
articleCount += unreadFeeds[maxThresIndexes[numOfFeeds]].UnreadCount.Value;
numOfFeeds++;
}
if (articleCount >= 6)
{
// There are enough new articles; update.
// Article getting process.
int index = 0;
while (articles.Count < 6)
{
if (index >= numOfFeeds)
{
index = 0;
}
// Query for the newest article of the chosen feed.
List <Article> sortedFeed = App.DataBaseUtility.QueryForSortedFeed(unreadFeeds, maxThresIndexes, index);
// Add the article, and temporarily change it to read so it won't be added again.
// Check to ensure that the query was successful, and unread articles do exist.
if (sortedFeed.Count == 0)
{
break;
}
else
{
Article newestArticle = sortedFeed[0];
articles.Add(newestArticle);
newestArticle.Read = true;
App.DataBaseUtility.SaveChangesToDB();
}
index++;
}
}
// Return the read values in the articles to unread.
ReturnArticlesToUnread(articles);
// Update the featured articles if successful (as in, 6 articles have been added).
if (articles.Count == 6)
{
Settings.FeaturedArticles = articles;
}
return;
}