[MediaCCC] Allow obtaining channel tab link handler

extractor/src/main/java/org/schabi/newpipe/extractor/services/media_ccc/MediaCCCService.java

@@ -19,6 +19,7 @@
 import org.schabi.newpipe.extractor.linkhandler.SearchQueryHandlerFactory;
 import org.schabi.newpipe.extractor.playlist.PlaylistExtractor;
 import org.schabi.newpipe.extractor.search.SearchExtractor;
+import org.schabi.newpipe.extractor.services.media_ccc.extractors.MediaCCCChannelTabExtractor;
 import org.schabi.newpipe.extractor.services.media_ccc.extractors.MediaCCCConferenceExtractor;
 import org.schabi.newpipe.extractor.services.media_ccc.extractors.MediaCCCConferenceKiosk;
 import org.schabi.newpipe.extractor.services.media_ccc.extractors.MediaCCCLiveStreamExtractor;
@@ -57,7 +58,9 @@ public ListLinkHandlerFactory getChannelLHFactory() {
 
     @Override
     public ListLinkHandlerFactory getChannelTabLHFactory() {
-        return null;
+        // there is just one channel tab in MediaCCC, the one containing conferences, so there is
+        // no need for a specific channel tab link handler, but we can just use the channel one
+        return MediaCCCConferenceLinkHandlerFactory.getInstance();
     }
 
     @Override
@@ -86,17 +89,13 @@ public ChannelExtractor getChannelExtractor(final ListLinkHandler linkHandler) {
     @Override
     public ChannelTabExtractor getChannelTabExtractor(final ListLinkHandler linkHandler) {
         if (linkHandler instanceof ReadyChannelTabListLinkHandler) {
+            // conference data has already been fetched, let the ReadyChannelTabListLinkHandler
+            // create a MediaCCCChannelTabExtractor with that data
             return ((ReadyChannelTabListLinkHandler) linkHandler).getChannelTabExtractor(this);
+        } else {
+            // conference data has not been fetched yet, so pass null instead
+            return new MediaCCCChannelTabExtractor(this, linkHandler, null);
         }
-
-        /*
-        Channel tab extractors are only supported in conferences and should only come from a
-        ReadyChannelTabListLinkHandler instance with a ChannelTabExtractorBuilder instance of the
-        conferences extractor
-
-        If that's not the case, return null in this case, so no channel tabs support
-        */
-        return null;
     }
 
     @Override

extractor/src/main/java/org/schabi/newpipe/extractor/services/media_ccc/extractors/MediaCCCChannelTabExtractor.java

@@ -0,0 +1,69 @@
+package org.schabi.newpipe.extractor.services.media_ccc.extractors;
+
+import com.grack.nanojson.JsonObject;
+
+import org.schabi.newpipe.extractor.InfoItem;
+import org.schabi.newpipe.extractor.ListExtractor;
+import org.schabi.newpipe.extractor.MultiInfoItemsCollector;
+import org.schabi.newpipe.extractor.Page;
+import org.schabi.newpipe.extractor.StreamingService;
+import org.schabi.newpipe.extractor.channel.tabs.ChannelTabExtractor;
+import org.schabi.newpipe.extractor.downloader.Downloader;
+import org.schabi.newpipe.extractor.exceptions.ExtractionException;
+import org.schabi.newpipe.extractor.linkhandler.ListLinkHandler;
+import org.schabi.newpipe.extractor.services.media_ccc.extractors.infoItems.MediaCCCStreamInfoItemExtractor;
+
+import java.io.IOException;
+import java.util.Objects;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+/**
+ * MediaCCC does not really have channel tabs, but rather a list of videos for each conference,
+ * so this class just acts as a videos channel tab extractor.
+ */
+public class MediaCCCChannelTabExtractor extends ChannelTabExtractor {
+    @Nullable
+    private JsonObject conferenceData;
+
+    /**
+     * @param conferenceData will be not-null if conference data has already been fetched by
+     *                       {@link MediaCCCConferenceExtractor}. Otherwise, if this parameter is
+     *                       {@code null}, conference data will be fetched anew.
+     */
+    public MediaCCCChannelTabExtractor(final StreamingService service,
+                                       final ListLinkHandler linkHandler,
+                                       @Nullable final JsonObject conferenceData) {
+        super(service, linkHandler);
+        this.conferenceData = conferenceData;
+    }
+
+    @Override
+    public void onFetchPage(@Nonnull final Downloader downloader)
+            throws ExtractionException, IOException {
+        if (conferenceData == null) {
+            // only fetch conference data if we don't have it already
+            conferenceData = MediaCCCConferenceExtractor.fetchConferenceData(downloader, getId());
+        }
+    }
+
+    @Nonnull
+    @Override
+    public ListExtractor.InfoItemsPage<InfoItem> getInitialPage() {
+        final MultiInfoItemsCollector collector =
+                new MultiInfoItemsCollector(getServiceId());
+        Objects.requireNonNull(conferenceData) // will surely be != null after onFetchPage
+                .getArray("events")
+                .stream()
+                .filter(JsonObject.class::isInstance)
+                .map(JsonObject.class::cast)
+                .forEach(event -> collector.commit(new MediaCCCStreamInfoItemExtractor(event)));
+        return new ListExtractor.InfoItemsPage<>(collector, null);
+    }
+
+    @Override
+    public ListExtractor.InfoItemsPage<InfoItem> getPage(final Page page) {
+        return ListExtractor.InfoItemsPage.emptyPage();
+    }
+}

extractor/src/main/java/org/schabi/newpipe/extractor/services/media_ccc/extractors/MediaCCCConferenceExtractor.java

@@ -1,24 +1,20 @@
 package org.schabi.newpipe.extractor.services.media_ccc.extractors;
 
+import static org.schabi.newpipe.extractor.services.media_ccc.extractors.MediaCCCParsingHelper.getImageListFromLogoImageUrl;
+
 import com.grack.nanojson.JsonObject;
 import com.grack.nanojson.JsonParser;
 import com.grack.nanojson.JsonParserException;
 
-import org.schabi.newpipe.extractor.InfoItem;
-import org.schabi.newpipe.extractor.ListExtractor;
-import org.schabi.newpipe.extractor.MultiInfoItemsCollector;
 import org.schabi.newpipe.extractor.Image;
-import org.schabi.newpipe.extractor.Page;
 import org.schabi.newpipe.extractor.StreamingService;
 import org.schabi.newpipe.extractor.channel.ChannelExtractor;
-import org.schabi.newpipe.extractor.channel.tabs.ChannelTabExtractor;
 import org.schabi.newpipe.extractor.channel.tabs.ChannelTabs;
 import org.schabi.newpipe.extractor.downloader.Downloader;
 import org.schabi.newpipe.extractor.exceptions.ExtractionException;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.linkhandler.ListLinkHandler;
 import org.schabi.newpipe.extractor.linkhandler.ReadyChannelTabListLinkHandler;
-import org.schabi.newpipe.extractor.services.media_ccc.extractors.infoItems.MediaCCCStreamInfoItemExtractor;
 import org.schabi.newpipe.extractor.services.media_ccc.linkHandler.MediaCCCConferenceLinkHandlerFactory;
 
 import java.io.IOException;
@@ -27,8 +23,6 @@
 
 import javax.annotation.Nonnull;
 
-import static org.schabi.newpipe.extractor.services.media_ccc.extractors.MediaCCCParsingHelper.getImageListFromLogoImageUrl;
-
 public class MediaCCCConferenceExtractor extends ChannelExtractor {
     private JsonObject conferenceData;
 
@@ -37,6 +31,19 @@ public MediaCCCConferenceExtractor(final StreamingService service,
         super(service, linkHandler);
     }
 
+    static JsonObject fetchConferenceData(@Nonnull final Downloader downloader,
+                                          @Nonnull final String conferenceId)
+            throws IOException, ExtractionException {
+        final String conferenceUrl
+                = MediaCCCConferenceLinkHandlerFactory.CONFERENCE_API_ENDPOINT + conferenceId;
+        try {
+            return JsonParser.object().from(downloader.get(conferenceUrl).responseBody());
+        } catch (final JsonParserException jpe) {
+            throw new ExtractionException("Could not parse json returned by URL: " + conferenceUrl);
+        }
+    }
+
+
     @Nonnull
     @Override
     public List<Image> getAvatars() {
@@ -88,76 +95,22 @@ public boolean isVerified() {
     @Nonnull
     @Override
     public List<ListLinkHandler> getTabs() throws ParsingException {
-        return List.of(new ReadyChannelTabListLinkHandler(getUrl(), getId(),
-                ChannelTabs.VIDEOS, new VideosTabExtractorBuilder(conferenceData)));
+        // avoid keeping a reference to MediaCCCConferenceExtractor inside the lambda
+        final JsonObject theConferenceData = conferenceData;
+        return List.of(new ReadyChannelTabListLinkHandler(getUrl(), getId(), ChannelTabs.VIDEOS,
+                (service, linkHandler) ->
+                        new MediaCCCChannelTabExtractor(service, linkHandler, theConferenceData)));
     }
 
     @Override
     public void onFetchPage(@Nonnull final Downloader downloader)
             throws IOException, ExtractionException {
-        final String conferenceUrl
-                = MediaCCCConferenceLinkHandlerFactory.CONFERENCE_API_ENDPOINT + getId();
-        try {
-            conferenceData = JsonParser.object().from(downloader.get(conferenceUrl).responseBody());
-        } catch (final JsonParserException jpe) {
-            throw new ExtractionException("Could not parse json returned by URL: " + conferenceUrl);
-        }
+        conferenceData = fetchConferenceData(downloader, getId());
     }
 
     @Nonnull
     @Override
     public String getName() throws ParsingException {
         return conferenceData.getString("title");
     }
-
-    private static final class VideosTabExtractorBuilder
-            implements ReadyChannelTabListLinkHandler.ChannelTabExtractorBuilder {
-
-        private final JsonObject conferenceData;
-
-        VideosTabExtractorBuilder(final JsonObject conferenceData) {
-            this.conferenceData = conferenceData;
-        }
-
-        @Nonnull
-        @Override
-        public ChannelTabExtractor build(@Nonnull final StreamingService service,
-                                         @Nonnull final ListLinkHandler linkHandler) {
-            return new VideosChannelTabExtractor(service, linkHandler, conferenceData);
-        }
-    }
-
-    private static final class VideosChannelTabExtractor extends ChannelTabExtractor {
-        private final JsonObject conferenceData;
-
-        VideosChannelTabExtractor(final StreamingService service,
-                                  final ListLinkHandler linkHandler,
-                                  final JsonObject conferenceData) {
-            super(service, linkHandler);
-            this.conferenceData = conferenceData;
-        }
-
-        @Override
-        public void onFetchPage(@Nonnull final Downloader downloader) {
-            // Nothing to do here, as data was already fetched
-        }
-
-        @Nonnull
-        @Override
-        public ListExtractor.InfoItemsPage<InfoItem> getInitialPage() {
-            final MultiInfoItemsCollector collector =
-                    new MultiInfoItemsCollector(getServiceId());
-            conferenceData.getArray("events")
-                    .stream()
-                    .filter(JsonObject.class::isInstance)
-                    .map(JsonObject.class::cast)
-                    .forEach(event -> collector.commit(new MediaCCCStreamInfoItemExtractor(event)));
-            return new InfoItemsPage<>(collector, null);
-        }
-
-        @Override
-        public InfoItemsPage<InfoItem> getPage(final Page page) {
-            return InfoItemsPage.emptyPage();
-        }
-    }
 }

extractor/src/main/java/org/schabi/newpipe/extractor/services/media_ccc/linkHandler/MediaCCCConferenceLinkHandlerFactory.java

@@ -1,11 +1,17 @@
 package org.schabi.newpipe.extractor.services.media_ccc.linkHandler;
 
+import org.schabi.newpipe.extractor.channel.tabs.ChannelTabs;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.linkhandler.ListLinkHandlerFactory;
 import org.schabi.newpipe.extractor.utils.Parser;
 
 import java.util.List;
 
+/**
+ * Since MediaCCC does not really have channel tabs (i.e. it only has one single "tab" with videos),
+ * this link handler acts both as the channel link handler and the channel tab link handler. That's
+ * why {@link #getAvailableContentFilter()} has been overridden.
+ */
 public final class MediaCCCConferenceLinkHandlerFactory extends ListLinkHandlerFactory {
 
     private static final MediaCCCConferenceLinkHandlerFactory INSTANCE
@@ -46,4 +52,15 @@ public boolean onAcceptUrl(final String url) {
             return false;
         }
     }
+
+    /**
+     * @see MediaCCCConferenceLinkHandlerFactory
+     * @return MediaCCC's only channel "tab", i.e. {@link ChannelTabs#VIDEOS}
+     */
+    @Override
+    public String[] getAvailableContentFilter() {
+        return new String[]{
+                ChannelTabs.VIDEOS,
+        };
+    }
 }

extractor/src/test/java/org/schabi/newpipe/extractor/services/media_ccc/MediaCCCChannelTabExtractorTest.java

@@ -0,0 +1,49 @@
+package org.schabi.newpipe.extractor.services.media_ccc;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.schabi.newpipe.extractor.ServiceList.MediaCCC;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.schabi.newpipe.downloader.DownloaderTestImpl;
+import org.schabi.newpipe.extractor.NewPipe;
+import org.schabi.newpipe.extractor.channel.tabs.ChannelTabExtractor;
+import org.schabi.newpipe.extractor.channel.tabs.ChannelTabs;
+
+/**
+ * Test that it is possible to create and use a channel tab extractor ({@link
+ * org.schabi.newpipe.extractor.services.media_ccc.extractors.MediaCCCChannelTabExtractor}) without
+ * passing through the conference extractor
+ */
+public class MediaCCCChannelTabExtractorTest {
+    public static class CCCamp2023 {
+        private static ChannelTabExtractor extractor;
+
+        @BeforeAll
+        public static void setUpClass() throws Exception {
+            NewPipe.init(DownloaderTestImpl.getInstance());
+            extractor = MediaCCC.getChannelTabExtractorFromId("camp2023", ChannelTabs.VIDEOS);
+            extractor.fetchPage();
+        }
+
+        @Test
+        void testName() {
+            assertEquals(ChannelTabs.VIDEOS, extractor.getName());
+        }
+
+        @Test
+        void testGetUrl() throws Exception {
+            assertEquals("https://media.ccc.de/c/camp2023", extractor.getUrl());
+        }
+
+        @Test
+        void testGetOriginalUrl() throws Exception {
+            assertEquals("https://media.ccc.de/c/camp2023", extractor.getOriginalUrl());
+        }
+
+        @Test
+        void testGetInitalPage() throws Exception {
+            assertEquals(177, extractor.getInitialPage().getItems().size());
+        }
+    }
+}

extractor/src/test/java/org/schabi/newpipe/extractor/services/media_ccc/MediaCCCConferenceExtractorTest.java

@@ -13,7 +13,8 @@
 import static org.schabi.newpipe.extractor.ServiceList.MediaCCC;
 
 /**
- * Test {@link MediaCCCConferenceExtractor}
+ * Test {@link MediaCCCConferenceExtractor} and {@link
+ * org.schabi.newpipe.extractor.services.media_ccc.extractors.MediaCCCChannelTabExtractor}
  */
 public class MediaCCCConferenceExtractorTest {
     public static class FrOSCon2017 {