- Add the ability to parse the RSS feeds from reddit groups (in particular the image feed groups like EarthPorn) and display them

src/pathtraverser.cpp

@@ -5,6 +5,8 @@
 #include <QDirIterator>
 #include <QDir>
 #include <QFileInfo>
+#include <QDomDocument>
+#include <QDomAttr>
 #include <iostream>
 #include <stdlib.h>     /* srand, rand */
 
@@ -108,5 +110,132 @@ ImageDisplayOptions ImageListPathTraverser::UpdateOptionsForImage(const std::str
   // no per file options modification supported
   Q_UNUSED(filename);
   Q_UNUSED(baseOptions);
-  return ImageDisplayOptions();
+  return baseOptions;
+}
+
+
+RedditRSSFeedPathTraverser::RedditRSSFeedPathTraverser(const std::string& rssFeedURLIn, QNetworkAccessManager& networkManager, bool debugModeIn) :
+  PathTraverser("",debugModeIn), rssFeedURL(rssFeedURLIn), webCtrl(networkManager)
+{
+  connect( &webCtrl, SIGNAL (finished(QNetworkReply*)), this, SLOT (fileDownloaded(QNetworkReply*)));
+  RequestRSSFeed();
+}
+
+RedditRSSFeedPathTraverser::~RedditRSSFeedPathTraverser()
+{
+}
+
+void RedditRSSFeedPathTraverser::RequestRSSFeed()
+{
+  if (pendingReply)
+  {
+    pendingReply->abort();
+  }
+  if (debugMode)
+  {
+    std::cout << "Requesting RSS feed:" << rssFeedURL << std::endl;
+  }
+  rssRequestedTime = QDateTime::currentDateTime();
+  QNetworkRequest request(QUrl(rssFeedURL.c_str()));
+  pendingReply = webCtrl.get(request);
+}
+
+void RedditRSSFeedPathTraverser::fileDownloaded(QNetworkReply* netReply) 
+{
+  if (netReply != pendingReply)
+    return;
+
+  pendingReply = nullptr;
+
+  QNetworkReply::NetworkError err = netReply->error();
+  if (err != QNetworkReply::NoError)
+  {
+    std::cout << "Failed to load Reddit RSS URL: " << err << std::endl;
+    return;
+  }
+
+  QString str (netReply->readAll());
+  QVariant vt = netReply->attribute(QNetworkRequest::RedirectionTargetAttribute);
+  netReply->deleteLater();
+  if (!vt.isNull())
+  {
+    if (debugMode)
+    {
+      std::cout << "Redirected to:" << vt.toUrl().toString().toStdString() << std::endl;
+    }
+    webCtrl.get(QNetworkRequest(vt.toUrl()));
+  }
+  else
+  {
+    QDomDocument doc;
+    QString error;
+    if (!doc.setContent(str, false, &error))
+    {
+      if (debugMode)
+      {
+        std::cout << "Failed to load page:" << error.toStdString() << std::endl;
+      }
+    }
+    else
+    {
+      QDomElement docElem = doc.documentElement();
+      QDomNodeList nodeList = docElem.elementsByTagName("entry"); 
+      for (int iEntry = 0; iEntry < nodeList.length(); ++iEntry)
+      {
+        QDomNode node = nodeList.item(iEntry);
+        QDomElement e = node.toElement();
+        QDomNode contentNode =  e.elementsByTagName("content").item(0).firstChild();
+        QDomDocument docContent;
+        if (!docContent.setContent(contentNode.nodeValue(), false, &error))
+        {
+          continue;
+        }
+
+        QDomNodeList addressEntries = docContent.documentElement().elementsByTagName("a");
+        for (int iAddr = 0; iAddr < addressEntries.length(); ++iAddr)
+        {
+          QDomNode node = addressEntries.item(iAddr);
+          /*QString output;
+          QTextStream stream(&output);
+          node.save(stream, 0);
+          qDebug() << "nodeValue: " << output;*/
+          if (node.toElement().text() == "[link]" && node.hasAttributes() )
+          {
+            QDomAttr a = node.toElement().attributeNode("href");
+            // check if the URL matches one of our supported formats
+            for ( const QString& format : supportedFormats ) 
+            {
+              if (a.value().endsWith(format))
+              {
+                imageURLS.append(a.value());
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
+
+
+QStringList RedditRSSFeedPathTraverser::getImages() const
+{
+  // refresh the feed after 5 hours
+  if (rssRequestedTime.secsTo(QDateTime::currentDateTime()) > 60*60*5 )
+  {
+    const_cast<RedditRSSFeedPathTraverser *>(this)->RequestRSSFeed(); 
+  }
+  return imageURLS;
+}
+
+const std::string RedditRSSFeedPathTraverser::getImagePath(const std::string image) const
+{
+  return image;
+}
+
+ImageDisplayOptions RedditRSSFeedPathTraverser::UpdateOptionsForImage(const std::string& filename, const ImageDisplayOptions& baseOptions) const
+{
+  // no per file options modification supported
+  Q_UNUSED(filename);
+  return baseOptions;
 }