/// <summary>
/// Calls the specified delegate recursively for each outline element
/// </summary>
/// <param name="collection">Collection with outline items</param>
/// <param name="callback">Delegate to call for each item</param>
private void RecursiveWorker(OpmlOutlineCollection collection, OutlineCallbackDelegate callback)
{
//
for (int i = 0; i < collection.Count; i++)
//foreach(OpmlOutlineFavorite o in collection)
{
OpmlOutlineFavorite o = (OpmlOutlineFavorite)collection[i];
//
if (o.Items.Count > 0)
{
RecursiveWorker(o.Items, callback);
}
else
{
try
{
callback(o);
}
catch (System.Exception e)
{
_exceptionTable.Add(o, e);
}
}
}
}
/// <summary>
/// Updates the history with the specified item
/// </summary>
/// <param name="item"></param>
private void UpdateHistory(OpmlOutlineFavorite item)
{
if (item.State != CacheState.Cached)
{
return;
}
//
if (FindOutline(item, _historyDocument.Body.Items))
{
return;
}
//
OpmlOutlineFavorite historyDayItem = null;
foreach (OpmlOutlineFavorite historyItem in _historyDocument.Body.Items)
{
TimeSpan span = historyItem.LastVisited.Subtract(item.LastVisited);
if (span.Days == 0)
{
historyDayItem = historyItem;
break;
}
}
// create on demand
if (historyDayItem == null)
{
historyDayItem = new OpmlOutlineFavorite();
historyDayItem.LastVisited = item.LastVisited;
historyDayItem.Text = item.LastVisited.ToString("dddd");
//
_historyDocument.Body.Items.Add(historyDayItem);
}
// add new item
historyDayItem.Items.Add(item);
}
/// <summary>
/// Reset the favorite to it's default values.
/// </summary>
/// <param name="item"></param>
private void ResetOutline(OpmlOutlineFavorite item)
{
System.IO.File.Delete(GetCachePathFromUri(new Uri(item.XmlUrl)));
item.State = CacheState.None;
item.TimesVisited = 0;
item.LastVisited = DateTime.MinValue;
}
private void RefreshOutline(OpmlOutlineFavorite item)
{
if (item.State == CacheState.Cached)
{
return;
}
//
this.GetFeed(item);
}
/// <summary>
/// Find the outline item that holds the requested uri.
/// </summary>
/// <param name="uri">The URI of the outline item to find.</param>
/// <param name="collection">RootCollection to search in.</param>
/// <returns></returns>
private OpmlOutlineFavorite FindOutlineByUri(Uri uri, System.Collections.ICollection collection)
{
foreach (OpmlOutlineFavorite o in collection)
{
if (object.Equals(o.XmlUrl, uri.AbsoluteUri))
{
return(o);
}
// recursive call
OpmlOutlineFavorite outline = FindOutlineByUri(uri, o.Items);
if (outline != null)
{
return(outline);
}
}
return(null);
}
/// <summary>
/// Recursive contains over the specified collection to find the outline item.
/// </summary>
/// <param name="uri">The URI of the outline item to find.</param>
/// <param name="collection">RootCollection to search in.</param>
/// <returns>True if the collection's hold this instance, otherwise False if not found.</returns>
private bool FindOutline(OpmlOutlineFavorite item, OpmlOutlineCollection collection)
{
if (collection.Contains(item))
{
return(true);
}
//
foreach (OpmlOutlineFavorite o in collection)
{
// recursive call
if (FindOutline(item, o.Items))
{
return(true);
}
}
return(false);
}
/// <summary>
/// RssFeedManager implements the operations to create <see cref="RssChannel"/> objects.
/// This class is responsible to manage the cache and is build to work with <see cref="OpmlOutlineFavorite"/> outline.
/// </summary>
/// <param name="outline">The <see cref="OpmlOutlineFavorite"/> of the resource to receive the data.</param>
/// <returns>The requested see cref="IRssChannel" instance</returns>
public IRssChannel GetFeed(OpmlOutlineFavorite outline)
{
Uri uri = new Uri(outline.XmlUrl);
IRssChannel rssChannel = null;
//System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.WaitCursor;
try
{
// never fetched before
if (outline.ExpireDate == DateTime.MinValue || outline.ExpireDate < DateTime.Now)
{
// fetch channel from web
rssChannel = InternalGetFeed(uri);
// save channel to cache
rssChannel.Save(GetCachePathFromUri(uri));
//
if (rssChannel.Ttl > 0)
{
outline.ExpireDate = DateTime.Now.AddMinutes(rssChannel.Ttl);
}
else
{
outline.ExpireDate = DateTime.Now.AddMinutes(3600);
}
//
outline.State = CacheState.Cached;
//
// add/refresh loaded channel to internal non persistent cache list
_rssChannelCacheList[outline] = rssChannel;
}
// check cache
else
{
// cached and not out of date
if (_rssChannelCacheList.Contains(outline))
{
rssChannel = _rssChannelCacheList[outline] as IRssChannel;
}
// cached but out of date, refresh
else
{
// fetch channel from web
rssChannel = InternalGetFeed(new Uri(GetCachePathFromUri(uri)));
outline.State = CacheState.Cached;
// update cache list
_rssChannelCacheList[outline] = rssChannel;
}
}
}
catch (System.Exception e)
{
System.Diagnostics.Debug.WriteLine(e.Message);
outline.State = CacheState.Error;
throw e;
}
finally
{
//System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.Default;
}
//
outline.TimesVisited++;
outline.LastVisited = DateTime.Now;
UpdateHistory(outline);
//
return(rssChannel);
}
