Render action performance

Question

I have view that display Question, Answers, Comments to answers and to Question.

To display all data i want to use something like this:

    [HttpGet, ChildActionOnly]
    public PartialViewResult RenderQuestion(int questionId, int page, int pageSize, string sort)//For question display
    {
        var question = questionsService.GetQuestion(questionId);
        var author = userService.GetUser(question.AuthorId);
        var commentIds = commentService.GetTopCommentIds(questionId, int.MaxValue, CommentType.Question);
        var answerIds = answerService.GetAnswerIdsByQuestion(page, pageSize, questionId, sort);
        var model = new QuestionModel{ Question = question, Author = author, CommentIds = commentIds, AnswerIds = answerIds}
        return PartialView("_Question", model);
    }
    [HttpGet, ChildActionOnly]
    public PartialViewResult RenderAnswer(int answerId)
    {
        var answer = answerService.GetAnswer(answerId);
        var author = userService.GetUser(answer.AuthorId);
        var commentIds = commentService.GetTopCommentIds(answerId, int.MaxValue, CommentType.Answer);
        var model = new AnswerModel { Answer = answer, Author = author, CommentIds = commentIds};
        return PartialView("_Answer");
    }

    [HttpGet, ChildActionOnly]
    public PartialViewResult RenderComment(int commentId, CommentType commentType)
    {
        var comment = commentService.GetComment(commentId, commentType);
        var author = userService.GetUser(comment.AuthorId);
        var model = new CommentModel { Comment = comment, Author = author};
        return PartialView("_Comment");
    }

And at my partial views for example for question i will iterate in loop Model.AnswerIds and call @{ Html.RenderAction("RenderAnswer", new {answerId}) }; and Model.CommentIds and call @{ Html.RenderAction("RenderComment", new {commentId}) };

I want to know, is it a good way of view decomposition and will this way have bad influence on performance caused often @Html.RenderAction calls.

Answer 1

Unfortunately, this will cause bad performance. RenderAction is not known for its blazing speed.

You will also instantiate your controller multiple times (possibly opening the database multiple times too).

I recommend you put everything into a single specialized controller action.