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

Question

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?

Answer 1

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"); 

Answer 2

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