public static new VkWallPostAttachment FromJson(JToken json)
        {
            if (json == null)
            {
                throw new ArgumentException("Json can not be null.");
            }

            var result = new VkWallPostAttachment();

            result.Id = (long)json["id"];

            if (json["owner_id"] != null)
            {
                result.OwnerId = (long)json["owner_id"];
            }

            if (json["from_id"] != null)
            {
                result.FromId = (long)json["from_id"];
            }

            if (json["to_id"] != null)
            {
                result.ToId = (long)json["to_id"];
            }

            if (json["date"] != null)
            {
                result.Date = DateTimeExtensions.UnixTimeStampToDateTime(json["date"].Value <long>());
            }

            if (json["post_type"] != null)
            {
                result.PostType = (string)json["post_type"];
            }

            if (json["text"] != null)
            {
                result.Text = (string)json["text"];
            }

            if (json["copy_history"] != null)
            {
                result.CopyHistory = new List <VkWallEntry>();

                foreach (var p in json["copy_history"])
                {
                    try
                    {
                        var post = VkWallEntry.FromJson(p);
                        if (post != null)
                        {
                            result.CopyHistory.Add(post);
                        }
                    }
                    catch (Exception ex)
                    {
                        Debug.WriteLine(ex);
                    }
                }
            }


            if (json["can_delete"] != null)
            {
                result.CanDelete = (int)json["can_delete"] == 1;
            }

            return(result);
        }
        public async Task <VkItemsResponse <VkWallEntry> > GetPosts(int count = 0, int offset = 0, bool extended = true)
        {
            var parameters = new Dictionary <string, string>();

            if (count > 0)
            {
                parameters.Add("count", count.ToString());
            }

            if (offset > 0)
            {
                parameters.Add("offset", offset.ToString());
            }

            if (extended)
            {
                parameters.Add("extended", "1");
            }

            _vkontakte.SignMethod(parameters);

            var response = await VkRequest.GetAsync(VkConst.MethodBase + "fave.getPosts", parameters);

            if (response.SelectToken("response.items") != null)
            {
                var result = new VkItemsResponse <VkWallEntry>((from n in response["response"]["items"] select VkWallEntry.FromJson(n)).ToList());

                if (response["response"]["profiles"] != null)
                {
                    var users = (from n in response["response"]["profiles"] select VkProfile.FromJson(n)).ToList();
                    foreach (var entry in result.Items)
                    {
                        entry.Author = users.FirstOrDefault(u => u.Id == entry.SourceId);
                    }
                }

                if (response["response"]["groups"] != null)
                {
                    var groups = (from n in response["response"]["groups"] select VkGroup.FromJson(n)).ToList();
                    foreach (var entry in result.Items.Where(e => e.Author == null))
                    {
                        entry.Author = groups.FirstOrDefault(g => g.Id == Math.Abs(entry.SourceId));
                    }
                }

                return(result);
            }

            return(null);
        }
        public async Task <VkItemsResponse <VkWallEntry> > GetPosts(int count = 0, int offset = 0, bool extended = true)
        {
            if (_vkontakte.AccessToken == null || string.IsNullOrEmpty(_vkontakte.AccessToken.Token) || _vkontakte.AccessToken.HasExpired)
            {
                throw new Exception("Access token is not valid.");
            }

            var parameters = new Dictionary <string, string>();

            if (count > 0)
            {
                parameters.Add("count", count.ToString());
            }

            if (offset > 0)
            {
                parameters.Add("offset", offset.ToString());
            }

            if (extended)
            {
                parameters.Add("extended", "1");
            }

            _vkontakte.SignMethod(parameters);

            var response = await new VkRequest(new Uri(VkConst.MethodBase + "fave.getPosts"), parameters).Execute();

            VkErrorProcessor.ProcessError(response);

            if (response.SelectToken("response.items") != null)
            {
                var result = new VkItemsResponse <VkWallEntry>((from n in response["response"]["items"] select VkWallEntry.FromJson(n)).ToList());

                if (response["response"]["profiles"] != null)
                {
                    var users = (from n in response["response"]["profiles"] select VkProfile.FromJson(n)).ToList();
                    foreach (var entry in result.Items)
                    {
                        entry.Author = users.FirstOrDefault(u => u.Id == entry.SourceId);
                    }
                }

                if (response["response"]["groups"] != null)
                {
                    var groups = (from n in response["response"]["groups"] select VkGroup.FromJson(n)).ToList();
                    foreach (var entry in result.Items.Where(e => e.Author == null))
                    {
                        entry.Author = groups.FirstOrDefault(g => g.Id == Math.Abs(entry.SourceId));
                    }
                }

                return(result);
            }

            return(null);
        }