Is RenderPartial async or is somewhat similar to jquery ajax call?

Question

I'm just curious and at the same time confused if RenderPartial in MVC(MVC5) is the same as an ajax call using jQuery, or to put simply is RenderPartial Async?

Answer 1

No. RenderPartial is sync.

But you can use an ajax call to a sync/async action if you are trying to get a sync, async behaviour.

'if RenderPartial in MVC(MVC5) is the same as an Ajax call using jQuery'

^ Let me explain.

For example you are using RenderPartial to render comments area of a post. From time to time, 30 seconds let's say, you can use an ajax call which will render latest comments and bring back to client-side the rendered html. Then you will replace your comments area html with what you receive from server in the response (ajax success callback).

Par example:

@model WhenToUseRenderActionAndRenderPartial.Models.ShowPostViewModel
@{
    ViewBag.Title = Model.Post.Title;
}

<section>
    <article>
        <header>
            <h1>@Model.Post.Title</h1>       
        Posted on | <time datetime="@Model.Post.DatePublished.ToString("s")">
           @Model.Post.DatePublished.ToLongDateString()
        </time> | @Model.Comments.Count() Comments
        </header>
        @Html.Raw(Model.Post.Content)
    </article> 
</section>
@{Html.RenderPartial("_Comments", Model.Comments);}

^ This is your post page razor view with a RenderPartial there for comments area.

@model IEnumerable<WhenToUseRenderActionAndRenderPartial.Models.Comment>
<section>
    <header>
        <h3>
            Comments</h3>
    </header>
    @foreach (var comment in Model)
    {
        <article>
            <header>
                @comment.Author on
                <time datetime="@comment.DateCreated.ToString("s") ">
                    @comment.DateCreated.ToLongDateString()
                </time>
            </header>
            <img alt="@comment.Author" src=@comment.ImageUrl />
            <p>
                @comment.Content
            </p>
        </article>
    }
</section>

^ This is your razor view for comments area.

And you can use the second view to render comments live (once 30 seconds). Ajax call to a method LiveController/BringLastCommentsfor PostId = 3 which will bring the comments and render only the comments partial view, not the entire page.

Some further reading here:

Render Partial http://www.arrangeactassert.com/when-to-use-html-renderpartial-and-html-renderaction-in-asp-net-mvc-razor-views/ (sweet diagrams)

Ajax http://kyleschaeffer.com/development/the-perfect-jquery-ajax-request/