Implemented opml writer

src/de/danoeh/antennapod/opml/OpmlSymbols.java

@@ -10,6 +10,9 @@ public final class OpmlSymbols {
 	public static final String XMLURL = "xmlUrl";
 	public static final String HTMLURL = "htmlUrl";
 	public static final String TYPE = "type";
+	public static final String VERSION = "version";
+	public static final String HEAD = "head";
+	public static final String TITLE = "title";
 	
 	private OpmlSymbols() {
 		

src/de/danoeh/antennapod/opml/OpmlWriter.java

@@ -0,0 +1,66 @@
+package de.danoeh.antennapod.opml;
+
+import java.io.IOException;
+import java.io.Writer;
+import java.util.List;
+
+import org.xmlpull.v1.XmlSerializer;
+
+import android.util.Log;
+import android.util.Xml;
+
+import de.danoeh.antennapod.AppConfig;
+import de.danoeh.antennapod.feed.Feed;
+
+/** Writes OPML documents. */
+public class OpmlWriter {
+	private static final String TAG = "OpmlWriter";
+	private static final String ENCODING = "UTF-8";
+	private static final String OPML_VERSION = "2.0";
+	private static final String OPML_TITLE = "AntennaPod Subscriptions";
+
+	/**
+	 * Takes a list of feeds and a writer and writes those into an OPML
+	 * document.
+	 * 
+	 * @throws IOException
+	 * @throws IllegalStateException
+	 * @throws IllegalArgumentException
+	 */
+	public void writeDocument(List<Feed> feeds, Writer writer)
+			throws IllegalArgumentException, IllegalStateException, IOException {
+		if (AppConfig.DEBUG)
+			Log.d(TAG, "Starting to write document");
+		XmlSerializer xs = Xml.newSerializer();
+		xs.setOutput(writer);
+
+		xs.startDocument(ENCODING, false);
+		xs.startTag(null, OpmlSymbols.OPML);
+		xs.attribute(null, OpmlSymbols.VERSION, OPML_VERSION);
+
+		xs.startTag(null, OpmlSymbols.HEAD);
+		xs.startTag(null, OpmlSymbols.TITLE);
+		xs.text(OPML_TITLE);
+		xs.endTag(null, OpmlSymbols.TITLE);
+		xs.endTag(null, OpmlSymbols.HEAD);
+
+		xs.startTag(null, OpmlSymbols.BODY);
+		for (Feed feed : feeds) {
+			xs.startTag(null, OpmlSymbols.OUTLINE);
+			xs.attribute(null, OpmlSymbols.TEXT, feed.getTitle());
+			if (feed.getType() != null) {
+				xs.attribute(null, OpmlSymbols.TYPE, feed.getType());
+			}
+			xs.attribute(null, OpmlSymbols.XMLURL, feed.getDownload_url());
+			if (feed.getLink() != null) {
+				xs.attribute(null, OpmlSymbols.HTMLURL, feed.getLink());
+			}
+			xs.endTag(null, OpmlSymbols.OUTLINE);
+		}
+		xs.endTag(null, OpmlSymbols.BODY);
+		xs.endTag(null, OpmlSymbols.OPML);
+		xs.endDocument();
+		if (AppConfig.DEBUG)
+			Log.d(TAG, "Finished writing document");
+	}
+}