/// <summary>
/// Overridden OnNavigatedTo handler
/// </summary>
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
if (isNewInstance)
{
if( State.ContainsKey( "CurrentItem" ) )
{
item = (RSSItem)State["CurrentItem"];
}
else
{
item = RSSService.SelectedItem;
}
isNewInstance = false;
}
}
/// <summary>
/// Creates the primitive HTML page from the article text.
/// Displays the first img-tag found (if any) and strips
/// other HTML away.
/// </summary>
/// <param name="article">Article text</param>
/// <returns>HTML page</returns>
public static String CreateArticleHTML(RSSItem item)
{
String start = @"<html>
<head>
<meta name=""Viewport"" content=""width=480; user-scaleable=no; initial-scale=1.0"" />
<style>
* { background: #fff !important; color: #000 !important; width: auto !important; font-size: 1em !important; }
h1 { font-size: 1.125em !important }
img { max-width: 200px !important; display: block; margin: 0 auto; }
.timestamp { font-size: 0.875em !important; font-style: italic; display: block; margin-top: 2em; }
</style>
</head>
<body>
<table>
<tr><td>";
String end = @"</td></tr></table></body></html>";
String headerTemplate = @"<tr><td><h1>{0}</h1></td></tr>";
String imageTemplate = @"<tr><td>{0}";
String articleTemplate = @"<span class=""article"">{0}</span></td></tr>";
String timestampTemplate = @"<tr><td><span class=""timestamp"">{0}</span></td></tr>";
String header = String.Format(headerTemplate, item.Title);
// If RSS item references an image in "enclosure" tag, use it. Otherwise try to extract the first image from the article
// Note about images: if we're using an image retrieved from closure, or the first image we retrieve
// from the article, doesn't specify image width or height, IE will not apply max-width property. This will
// result in us showing larger pictures than intended. This could be worked around by using JavaScript resize
// the images.
String image = "";
if (item.Image != null && item.Image != "")
{
// Image from enclosure
String imgTemplate = @"<img src=""{0}"" />";
image = String.Format( imageTemplate, String.Format(imgTemplate, item.Image ));
}
else
{
Regex img = new Regex("<img.*?>", RegexOptions.IgnoreCase);
MatchCollection matches = img.Matches(item.Text);
if (matches.Count > 0 && matches[0] != null)
{
// Image from article content
image = String.Format(imageTemplate, matches[0].Groups[0].Value);
}
else
{
// No image
image = String.Format(imageTemplate, "");
}
}
String article = String.Format( articleTemplate, HttpUtility.HtmlDecode(Regex.Replace(item.Text, "<.*?>", "") ) );
String timestamp = String.Format(timestampTemplate, item.Datestamp);
StringBuilder builder = new StringBuilder();
builder.Append(start);
builder.Append(header);
builder.Append(image);
builder.Append(article);
builder.Append(timestamp);
builder.Append(end);
return builder.ToString();
}
/// <summary>
/// Gets the RSS items
/// </summary>
/// <param name="feed">The RSS feed</param>
/// <param name="onGetRSSItemsCompleted">Callback on complete</param>
/// <param name="onError">Callback for errors</param>
public static void GetRSSItems(int pageId, int feedId, bool useCache, Action<IEnumerable<RSSItem>> onGetRSSItemsCompleted = null, Action<Exception> onError = null)
{
DateTime validUntilThis = DateTime.Now;
validUntilThis = validUntilThis.AddMinutes(-EXPIRE_TIME);
RSSFeed feed = GetRSSFeed(pageId, feedId);
bool feedExists = (feed != null);
bool feedHasItems = (feedExists && feed.Items != null && feed.Items.Count > 0);
bool cacheHasExpired = (DateTime.Compare(validUntilThis, feed.Timestamp) > 0);
// First check if this valid items for this feed exist in the cache already
if (feedExists &&
feedHasItems &&
useCache &&
!cacheHasExpired &&
onGetRSSItemsCompleted != null)
{
onGetRSSItemsCompleted(feed.Items);
}
// Items not found in cache, perform a web request
else
{
WebClient webClient = new WebClient();
webClient.OpenReadCompleted += delegate(object sender, OpenReadCompletedEventArgs e)
{
try
{
if (e.Error != null)
{
if (onError != null)
{
onError(e.Error);
}
return;
}
List<RSSItem> rssItems = new List<RSSItem>();
XmlReader response = XmlReader.Create(e.Result);
SyndicationFeed rssFeed = SyndicationFeed.Load(response);
foreach (SyndicationItem syndicationItem in rssFeed.Items)
{
// Clean the title in case it includes line breaks
string title = syndicationItem.Title.Text;
title = title.Replace("\r\n", "\n").Replace("\r", "\n").Replace("\n", " ");
// Check for "enclosure" tag that references an image
string image = "";
foreach (SyndicationLink link in syndicationItem.Links)
{
if (link.RelationshipType == "enclosure" &&
link.MediaType.StartsWith( "image/" ) )
{
image = link.Uri.ToString();
break;
}
}
RSSItem rssItem = new RSSItem(
title,
syndicationItem.Summary.Text,
syndicationItem.Links[0].Uri.AbsoluteUri,
syndicationItem.PublishDate,
feed,
image);
rssItems.Add(rssItem);
}
// Cache the results
feed.Items = rssItems;
feed.Timestamp = DateTime.Now;
// Call the callback with the list of RSSItems
if (onGetRSSItemsCompleted != null)
{
onGetRSSItemsCompleted(rssItems);
}
}
catch (Exception error)
{
if (onError != null)
{
onError(error);
}
}
};
webClient.OpenReadAsync(new Uri(feed.URL));
}
}
/// <summary>
/// Creates the primitive HTML page from the article text.
/// Displays the first img-tag found (if any) and strips
/// other HTML away.
/// </summary>
/// <param name="article">Article text</param>
/// <returns>HTML page</returns>
public static String CreateArticleHTML(RSSItem item)
{
String start = @"<html>
<head>
<meta name=""Viewport"" content=""width=480; user-scaleable=no; initial-scale=1.0"" />
<style>
* { background: #fff !important; color: #000 !important; width: auto !important; font-size: 1em !important; }
h1 { font-size: 1.125em !important }
img { max-width: 200px !important; display: block; margin: 0 auto; }
.timestamp { font-size: 0.875em !important; font-style: italic; display: block; margin-top: 2em; }
</style>
</head>
<body>
<table>
<tr><td>";
String end = @"</td></tr></table></body></html>";
String headerTemplate = @"<tr><td><h1>{0}</h1></td></tr>";
String imageTemplate = @"<tr><td>{0}";
String articleTemplate = @"<span class=""article"">{0}</span></td></tr>";
String timestampTemplate = @"<tr><td><span class=""timestamp"">{0}</span></td></tr>";
String header = String.Format(headerTemplate, item.Title);
// If RSS item references an image in "enclosure" tag, use it. Otherwise try to extract the first image from the article
// Note about images: if we're using an image retrieved from closure, or the first image we retrieve
// from the article, doesn't specify image width or height, IE will not apply max-width property. This will
// result in us showing larger pictures than intended. This could be worked around by using JavaScript resize
// the images.
String image = "";
if (item.Image != null && item.Image != "")
{
// Image from enclosure
String imgTemplate = @"<img src=""{0}"" />";
image = String.Format(imageTemplate, String.Format(imgTemplate, item.Image));
}
else
{
Regex img = new Regex("<img.*?>", RegexOptions.IgnoreCase);
MatchCollection matches = img.Matches(item.Text);
if (matches.Count > 0 && matches[0] != null)
{
// Image from article content
image = String.Format(imageTemplate, matches[0].Groups[0].Value);
}
else
{
// No image
image = String.Format(imageTemplate, "");
}
}
String article = String.Format(articleTemplate, HttpUtility.HtmlDecode(Regex.Replace(item.Text, "<.*?>", "")));
String timestamp = String.Format(timestampTemplate, item.Datestamp);
StringBuilder builder = new StringBuilder();
builder.Append(start);
builder.Append(header);
builder.Append(image);
builder.Append(article);
builder.Append(timestamp);
builder.Append(end);
return(builder.ToString());
}
/// <summary>
/// Gets the RSS items
/// </summary>
/// <param name="feed">The RSS feed</param>
/// <param name="onGetRSSItemsCompleted">Callback on complete</param>
/// <param name="onError">Callback for errors</param>
public static void GetRSSItems(int pageId, int feedId, bool useCache, Action <IEnumerable <RSSItem> > onGetRSSItemsCompleted = null, Action <Exception> onError = null)
{
DateTime validUntilThis = DateTime.Now;
validUntilThis = validUntilThis.AddMinutes(-EXPIRE_TIME);
RSSFeed feed = GetRSSFeed(pageId, feedId);
bool feedExists = (feed != null);
bool feedHasItems = (feedExists && feed.Items != null && feed.Items.Count > 0);
bool cacheHasExpired = (DateTime.Compare(validUntilThis, feed.Timestamp) > 0);
// First check if this valid items for this feed exist in the cache already
if (feedExists &&
feedHasItems &&
useCache &&
!cacheHasExpired &&
onGetRSSItemsCompleted != null)
{
onGetRSSItemsCompleted(feed.Items);
}
// Items not found in cache, perform a web request
else
{
WebClient webClient = new WebClient();
webClient.OpenReadCompleted += delegate(object sender, OpenReadCompletedEventArgs e)
{
try
{
if (e.Error != null)
{
if (onError != null)
{
onError(e.Error);
}
return;
}
List <RSSItem> rssItems = new List <RSSItem>();
XmlReader response = XmlReader.Create(e.Result);
SyndicationFeed rssFeed = SyndicationFeed.Load(response);
foreach (SyndicationItem syndicationItem in rssFeed.Items)
{
// Clean the title in case it includes line breaks
string title = syndicationItem.Title.Text;
title = title.Replace("\r\n", "\n").Replace("\r", "\n").Replace("\n", " ");
// Check for "enclosure" tag that references an image
string image = "";
foreach (SyndicationLink link in syndicationItem.Links)
{
if (link.RelationshipType == "enclosure" &&
link.MediaType.StartsWith("image/"))
{
image = link.Uri.ToString();
break;
}
}
RSSItem rssItem = new RSSItem(
title,
syndicationItem.Summary.Text,
syndicationItem.Links[0].Uri.AbsoluteUri,
syndicationItem.PublishDate,
feed,
image);
rssItems.Add(rssItem);
}
// Cache the results
feed.Items = rssItems;
feed.Timestamp = DateTime.Now;
// Call the callback with the list of RSSItems
if (onGetRSSItemsCompleted != null)
{
onGetRSSItemsCompleted(rssItems);
}
}
catch (Exception error)
{
if (onError != null)
{
onError(error);
}
}
};
webClient.OpenReadAsync(new Uri(feed.URL));
}
}
