Add checks if page is fetched

Author: coffeemakr

src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeStreamExtractor.java

@@ -105,6 +105,7 @@ public String getId() throws ParsingException {
     @Nonnull
     @Override
     public String getName() throws ParsingException {
+        assertPageFetched();
         String name = getStringFromMetaData("title");
         if(name == null) {
             // Fallback to HTML method
@@ -123,6 +124,7 @@ public String getName() throws ParsingException {
     @Nonnull
     @Override
     public String getUploadDate() throws ParsingException {
+        assertPageFetched();
         try {
             return doc.select("meta[itemprop=datePublished]").attr(CONTENT);
         } catch (Exception e) {//todo: add fallback method
@@ -133,6 +135,7 @@ public String getUploadDate() throws ParsingException {
     @Nonnull
     @Override
     public String getThumbnailUrl() throws ParsingException {
+        assertPageFetched();
         // Try to get high resolution thumbnail first, if it fails, use low res from the player instead
         try {
             return doc.select("link[itemprop=\"thumbnailUrl\"]").first().attr("abs:href");
@@ -156,6 +159,7 @@ public String getThumbnailUrl() throws ParsingException {
     @Nonnull
     @Override
     public String getDescription() throws ParsingException {
+        assertPageFetched();
         try {
             return doc.select("p[id=\"eow-description\"]").first().html();
         } catch (Exception e) {//todo: add fallback method <-- there is no ... as long as i know
@@ -165,6 +169,7 @@ public String getDescription() throws ParsingException {
 
     @Override
     public int getAgeLimit() throws ParsingException {
+        assertPageFetched();
         if (!isAgeRestricted) {
             return NO_AGE_LIMIT;
         }
@@ -178,6 +183,7 @@ public int getAgeLimit() throws ParsingException {
 
     @Override
     public long getLength() throws ParsingException {
+        assertPageFetched();
         if(playerArgs != null) {
             try {
                 long returnValue = Long.parseLong(playerArgs.get("length_seconds") + "");
@@ -216,6 +222,7 @@ public long getTimeStamp() throws ParsingException {
 
     @Override
     public long getViewCount() throws ParsingException {
+        assertPageFetched();
         try {
             return Long.parseLong(doc.select("meta[itemprop=interactionCount]").attr(CONTENT));
         } catch (Exception e) {//todo: find fallback method
@@ -225,6 +232,7 @@ public long getViewCount() throws ParsingException {
 
     @Override
     public long getLikeCount() throws ParsingException {
+        assertPageFetched();
         String likesString = "";
         try {
             Element button = doc.select("button.like-button-renderer-like-button").first();
@@ -244,6 +252,7 @@ public long getLikeCount() throws ParsingException {
 
     @Override
     public long getDislikeCount() throws ParsingException {
+        assertPageFetched();
         String dislikesString = "";
         try {
             Element button = doc.select("button.like-button-renderer-dislike-button").first();
@@ -264,6 +273,7 @@ public long getDislikeCount() throws ParsingException {
     @Nonnull
     @Override
     public String getUploaderUrl() throws ParsingException {
+        assertPageFetched();
         try {
             return doc.select("div[class=\"yt-user-info\"]").first().children()
                     .select("a").first().attr("abs:href");
@@ -275,6 +285,7 @@ public String getUploaderUrl() throws ParsingException {
 
     @Nullable
     private String getStringFromMetaData(String field) {
+        assertPageFetched();
         String value = null;
         if(playerArgs != null) {
             // This can not fail
@@ -290,6 +301,7 @@ private String getStringFromMetaData(String field) {
     @Nonnull
     @Override
     public String getUploaderName() throws ParsingException {
+        assertPageFetched();
         String name = getStringFromMetaData("author");
 
         if(name == null) {
@@ -309,6 +321,7 @@ public String getUploaderName() throws ParsingException {
     @Nonnull
     @Override
     public String getUploaderAvatarUrl() throws ParsingException {
+        assertPageFetched();
         try {
             return doc.select("a[class*=\"yt-user-photo\"]").first()
                     .select("img").first()
@@ -320,6 +333,7 @@ public String getUploaderAvatarUrl() throws ParsingException {
 
     @Override
     public String getDashMpdUrl() throws ParsingException {
+        assertPageFetched();
         try {
             String dashManifestUrl;
             if (videoInfoPage.containsKey("dashmpd")) {
@@ -346,6 +360,7 @@ public String getDashMpdUrl() throws ParsingException {
 
     @Override
     public List<AudioStream> getAudioStreams() throws IOException, ExtractionException {
+        assertPageFetched();
         List<AudioStream> audioStreams = new ArrayList<>();
         try {
             for (Map.Entry<String, ItagItem> entry : getItags(ADAPTIVE_FMTS, ItagItem.ItagType.AUDIO).entrySet()) {
@@ -365,6 +380,7 @@ public List<AudioStream> getAudioStreams() throws IOException, ExtractionExcepti
 
     @Override
     public List<VideoStream> getVideoStreams() throws IOException, ExtractionException {
+        assertPageFetched();
         List<VideoStream> videoStreams = new ArrayList<>();
         try {
             for (Map.Entry<String, ItagItem> entry : getItags(URL_ENCODED_FMT_STREAM_MAP, ItagItem.ItagType.VIDEO).entrySet()) {
@@ -384,6 +400,7 @@ public List<VideoStream> getVideoStreams() throws IOException, ExtractionExcepti
 
     @Override
     public List<VideoStream> getVideoOnlyStreams() throws IOException, ExtractionException {
+        assertPageFetched();
         List<VideoStream> videoOnlyStreams = new ArrayList<>();
         try {
             for (Map.Entry<String, ItagItem> entry : getItags(ADAPTIVE_FMTS, ItagItem.ItagType.VIDEO_ONLY).entrySet()) {
@@ -410,6 +427,7 @@ public List<Subtitles> getSubtitlesDefault() throws IOException, ExtractionExcep
     @Override
     @Nullable
     public List<Subtitles> getSubtitles(SubtitlesFormat format) throws IOException, ExtractionException {
+        assertPageFetched();
         if(isAgeRestricted) {
             // If the video is age restricted getPlayerConfig will fail
             return null;
@@ -459,6 +477,7 @@ public StreamType getStreamType() throws ParsingException {
 
     @Override
     public StreamInfoItem getNextVideo() throws IOException, ExtractionException {
+        assertPageFetched();
         try {
             StreamInfoItemCollector collector = new StreamInfoItemCollector(getServiceId());
             collector.commit(extractVideoPreviewInfo(doc.select("div[class=\"watch-sidebar-section\"]")
@@ -472,6 +491,7 @@ public StreamInfoItem getNextVideo() throws IOException, ExtractionException {
 
     @Override
     public StreamInfoItemCollector getRelatedVideos() throws IOException, ExtractionException {
+        assertPageFetched();
         try {
             StreamInfoItemCollector collector = new StreamInfoItemCollector(getServiceId());
             Element ul = doc.select("ul[id=\"watch-related\"]").first();