Ajax.ActionLink, get data or error message from controller?

actionlink, asp.net-ajax, asp.net-mvc

Solution

public ActionResult Upvote(Guid QuestionID)
{
    if (...)
    {
        return Content("some error message");
    }
    else 
    {
        return Content("5 votes");
    }
}

Whatever text you return in the content result will be inserted into the div.

Another possibility is to use JSON:

public ActionResult Upvote(Guid QuestionID)
{
    if (...)
    {
        return Json(new { error = "some error message" }, JsonRequestBehavior.AllowGet);
    }
    else 
    {
        return Json(new { votes = 5 }, JsonRequestBehavior.AllowGet);
    }
}

and then:

@Ajax.ActionLink("Upvote", "Upvote", "Author", new { QuestionID = Model.QuestionID, @class = "upvote" },
new AjaxOptions
{
     OnSuccess = "onSuccess"
})

and finally inside the onSuccess callback:

function onSuccess(result) {
    if (result.error) {
        alert(result.error);
    } else {
        $('#vote_count').html(result.votes);   
    }
}

Problem

Here is a spot that I want to update: ``` <div style="text-align: center;" id="vote_count">@Html.DisplayFor(q => q.VoteCount)</div> ``` Here is my actionLink: ``` @Ajax.ActionLink("Upvote", "Upvote", "Author", new { QuestionID = Model.QuestionID, @class = "upvote" }, new AjaxOptions { InsertionMode = InsertionMode.Replace, UpdateTargetId = "vote_count", OnBegin = "onBegin", OnComplete = "onComplete", OnSuccess = "onSuccess", OnFailure = "onFailure" }) ``` And here is one of my controllers: ``` public int Upvote(Guid QuestionID) { if () { //I want to send error message } else { //I want to send an integer } } ``` And my question: I want to send error message or an integer to my view page to show it. How can I do it? From advices that you have recommended, I can change all codes. Thanks.

Original source