Styjun

Is there a way to add a JSON Result that would be consumed by the OnSuccess or OnFailure options of an AJAX.BeginForm when the controller is using the return View(model) syntax?

Everything is pretty standard C# / MVC. The Ajax.BeginForm would look like this

@using (Ajax.BeginForm("AnyAction", "Home", null,
 new AjaxOptions
 
 HttpMethod = "Post",
 OnBegin = "OnBegin",
 OnFailure = "OnFailure(xhr, status)",
 OnSuccess = "OnSuccess(xhr, status)"
 ,
 new id = "myform" ))

The OnSuccess and OnFailure scripts are defined like this

 function OnSuccess(xhr, status) 
 console.log("OnSuccess");
 
 function OnFailure(xhr, status) 
 console.log("OnFailure"); 
 

The controller returns like this

 HttpContext.Response.StatusCode = (int)HttpStatusCode.NotAcceptable;
 return View(model);

I can inject the HTTPStatusCode, either OK or Not OK, into the HTTPContext.Response and that will trigger the OnSuccess or OnFailure javascript functions. From that I know that I can manipulate the response stream but is there anyway to add a JSON response to the HTTPContext.Response such that the OnSuccess or OnFailure can consume it.

How can I pass this, while using the return View(model) syntax, to the OnSuccess function?

dynamic jsonMessage;
jsonMessage = new param1 = "ModelState", param2 ="Error", param3 = "Error Message" ;

Some quick notes:

This is not a requirement, just a question.

I am already using the Return JSON(jsonMessage, JsonRequestBehavior.AllowGet) elsewhere in my project, don't need help with that.

Since your JSON is small, you could add your JSON string as a response header using

HttpContext.Response.AddHeader("json", "json_string");.

It can then be accessed from the header value in OnSuccess/Failure method.

I wanted to follow up with the my final solution. First we need to adjust the OnSuccess definition of the Ajax.BeginForm property to look like this. I tried several variations of this but this exact code is the only one that worked.

@using (Ajax.BeginForm("AddUserRole", "AppRoles", null,
 new AjaxOptions
 
 HttpMethod = "Post",
 OnBegin = "OnBegin",
 OnFailure = "OnFailure(xhr, status)",
 OnSuccess = "OnSuccess(data, status, xhr)"
 ,
 new id = "myform" ))

Next the javascript for the OnSuccess looks like this. A few things to note; first the controller, shown farther down, can return either a JsonResult or a View / Model. The OnSuccess function will be fired regardless of which is returned as long as the HttpResponseStatus is OK. If the controller returns a View/Model, the data parm will contain the entire rendered view and the json I want will be in the XHR parameter. To work with the json response it must be extracted using the getResponseHeader and then serialized to JSON. After that we can work with it as a regular old JSON object.

function OnSuccess(data, status, xhr) 
 console.log("OnSuccess");
 // this is for capturing from the Response header WHEN the controller returns a view
 var srchMessage = xhr.getResponseHeader("srchMessage")
 if (srchMessage != null) 
 var srchJson = JSON.parse(srchMessage);
 console.log("srchMessage:param1" + srchJson.param1);
 return;
 
 // this is for capturing the json WHEN the controller returns a JsonResult
 if (xhr.responseJSON != null) 
 console.log("xhr.responseJSON.param1" + xhr.responseJSON.param1);
 

The MVC controller can return either a 'short' JsonResult or the complete view, looks kinda like this

public ActionResult AjaxTest(AppModel model)

 if (model.status == "ReturnView")
 
 jsonMessage = new param1 = "param1", param2 = "param2", param3 = "param3" ;
 string jsonString = Newtonsoft.Json.JsonConvert.SerializeObject(jsonMessage);
 HttpContext.Response.AddHeader("srchMessage", jsonString);
 HttpContext.Response.StatusCode = (int)HttpStatusCode.OK;
 return View(model);
 

 if (model.status == "ReturnJSON")
 
 jsonMessage = new param1 = "param1", param2 = "param2", param3 = "param3" ;
 HttpContext.Response.StatusCode = (int)HttpStatusCode.OK;
 return Json(jsonMessage, JsonRequestBehavior.AllowGet);
 

I'm not sure why I wanted to do this, I should have separate controllers for the different actions, but this is how it can be done if you wanted to do it.