Friday, May 18, 2012

ASP.NET MVC controller actions that return JSON or partial html


I am trying to create controller actions which will return either JSON or partial html depending upon a parameter. What is the best way to get the result returned to an MVC page asynchronously?



Source: Tips4all
Post by On
Tags , , , , ,

5 comments:

  1. UserMay 18, 2012 at 7:59 PM

    In your action method, return Json(object) to return JSON to your page.

    public ActionResult SomeActionMethod() {
    return Json(new {foo="bar", baz="Blech"});
    }


    Then just call the action method using Ajax. You could use one of the helper methods from the ViewPage such as

    <%= Ajax.ActionLink("SomeActionMethod", new AjaxOptions {OnSuccess="somemethod"}) %>


    SomeMethod would be a javascript method that then evaluates the Json object returned.

    If you want to return a plain string, you can just use the ContentResult:

    public ActionResult SomeActionMethod() {
    return Content("hello world!");
    }


    ContentResult by default returns a text/plain as its contentType.
    This is overloadable so you can also do:

    return Content("<xml>This is poorly formatted xml.</xml>", "text/xml");

    ReplyDelete
  2. UserMay 18, 2012 at 7:59 PM

    NathanD,

    I think you should consider the AcceptTypes of the request. I am using it in my current project to return the correct content type as follows.

    Your action on the controller can test it as on the request object

    if (Request.AcceptTypes.Contains("text/html")) {
    return View();
    }
    else if (Request.AcceptTypes.Contains("application/json"))
    {
    return Json( new { id=1, value="new" } );
    }
    else if (Request.AcceptTypes.Contains("application/xml") ||
    Request.AcceptTypes.Contains("text/xml"))
    {
    //
    }


    You can then implement the aspx of the view to cater for the partial xhtml response case.

    Then in jQuery you can fetch it passing the type parameter as json:

    $.get(url, null, function(data, textStatus) {
    console.log('got %o with status %s', data, textStatus);
    }, "json"); // or xml, html, script, json, jsonp or text


    Hope this helps
    James

    ReplyDelete
  3. UserMay 18, 2012 at 7:59 PM

    Another nice way to deal with JSON data is using the JQuery getJSON function. You can call the

    public ActionResult SomeActionMethod(int id)
    {
    return Json(new {foo="bar", baz="Blech"});
    }


    method from the jquery getJSON method by simply...

    $.getJSON("../SomeActionMethod", {
    id: someId
    },
    function(data) {
    alert(data.foo);
    alert(data.baz);}

    ReplyDelete
  4. UserMay 18, 2012 at 7:59 PM

    To answer the other half of the question, you can call:

    return PartialView("viewname");


    when you want to return partial HTML. You'll just have to find some way to decide whether the request wants JSON or HTML, perhaps based on a URL part/parameter.

    ReplyDelete
  5. UserMay 18, 2012 at 7:59 PM

    For folks who have upgraded to MVC 3 here is a neat way
    Using MVC3 and Json

    ReplyDelete

Subscribe to: Post Comments (Atom)