Merge pull request #4204 from wordpress-mobile/issue/2647-remove-posts-from-unfollowed-blogs

Remove posts from unfollowed blogs from reader

Author: nbradbury

WordPress/src/main/java/org/wordpress/android/datasets/ReaderPostTable.java

@@ -398,6 +398,14 @@ public static int deletePostsWithTag(final ReaderTag tag) {
         return numDeleted;
     }
 
+    /*
+    * delete all the posts from the blogs we no longer follow
+    */
+    public static int deletePostsFromUnfollowedBlogs() {
+       return ReaderDatabase.getWritableDb().delete("tbl_posts",
+                "blog_id NOT IN (SELECT DISTINCT blog_id FROM tbl_blog_info WHERE tbl_blog_info.is_following != 0)", null);
+    }
+
     public static int deletePostsInBlog(long blogId) {
         String[] args = {Long.toString(blogId)};
         return ReaderDatabase.getWritableDb().delete("tbl_posts", "blog_id = ?", args);

WordPress/src/main/java/org/wordpress/android/ui/reader/services/ReaderUpdateService.java

@@ -261,16 +261,24 @@ public void onErrorResponse(VolleyError volleyError) {
         // request using ?meta=site,feed to get extra info
         WordPress.getRestClientUtilsV1_1().get("read/following/mine?meta=site%2Cfeed", listener, errorListener);
     }
+
     private void handleFollowedBlogsResponse(final JSONObject jsonObject) {
         new Thread() {
             @Override
             public void run() {
                 ReaderBlogList serverBlogs = ReaderBlogList.fromJson(jsonObject);
                 ReaderBlogList localBlogs = ReaderBlogTable.getFollowedBlogs();
 
-                if (!localBlogs.isSameList(serverBlogs)) {
+                boolean followedBlogsChanged = !localBlogs.isSameList(serverBlogs);
+
+                if (followedBlogsChanged) {
                     ReaderBlogTable.setFollowedBlogs(serverBlogs);
                     AppLog.d(AppLog.T.READER, "reader blogs service > followed blogs changed");
+                }
+
+                int numberOfDeletedPosts = ReaderPostTable.deletePostsFromUnfollowedBlogs();
+
+                if (followedBlogsChanged || numberOfDeletedPosts > 0) {
                     EventBus.getDefault().post(new ReaderEvents.FollowedBlogsChanged());
                 }