Receive an array in the controller from javascript

Question

I am creating an array with a javascript data list:

var myArray = gvSortingListagemGARs.keys;

Where I have the result:

[278, 279, 280, 281, 282]

Who are id's of elements of a Devexpress table. Now I’m trying to pass this array to my controller, it just keeps receiving null.

My function js

function downloadListaGARSTratadas() {
    var myArray = gvSortingListagemGARs.keys;
    alert(myArray);
    window.location.href = "/GAR/downloadListaGARsTratadas?GarsFiltro=" + myArray +"";
}

Function in the controller

public ActionResult downloadListaGARsTratadas(int[] GarsFiltro)
{ ... }

If you do string instead of int[] receiving 278, 279, 280, 281, 282, or is the variable. Cannot receive even with an integer array?

Answer 1

You must specify that it is an array like this and pass each value as a parameter, only all with the same name, for example:

/?arr[]=foo+bar&arr[]=baz&arr[]=foo

Or still for some cases (such as ASP MVC):

/?arr=foo+bar&arr=baz&arr=foo

As demonstrated in that and in that topic of SO-EN and in that post

So in your case you should do something like:

window.location.href = "/GAR/downloadListaGARsTratadas?GarsFiltro=1&GarsFiltro=2&GarsFiltro=3"

To generate this parameter dynamically I created this method:

function formatQueryStringURLParamArray(key, array){
    var param = "";
    for(var item in array){
        if(param.length > 0)
            param += "&";
        param += key + "=" + item;
    }
    return param;
}

Which can be called this way by returning the formatted querystring:

var param = formatQueryStringURLParamArray("key", myArray);

Here’s a online example.

Example with Web API

Try the following test (I use Webapi ASP MVC, but it is very similar to MVC):

I created the following Apicontroller:

public class Test2Controller : ApiController
{
    [HttpGet]
    public virtual int Get([FromUri]int[] i)
    {
        return i.Length;
    }
}

And I made the following request via url in my browser:

http://localhost:59402/api/test2/?i[]=1&i[]=2&i[]=3

And I got the integer array correctly.

I don’t know if MVC uses this because I don’t work with MVC just Webapi, but try adding [FromUri] before its array parameter in the Controller method.

Example with ASP MVC

I created this Controller:

public class Test3Controller : Controller
{
    [System.Web.Http.HttpGet]
    public ActionResult Index([FromUri]int[] i)
    {
        return Json(i, JsonRequestBehavior.AllowGet);
    }
}

And I made the following request via url in my browser:

http://localhost:59402/test3/?i=1&i=2&i=3

Note: I don’t know why MVC didn’t understand when I was passing by i[], so if I just pass i={valor}, he understands. Already Web API worked both ways: i={valor} and i[]={valor}.

Answer 2

@Cesarmiguel, the error you are having has nothing to do, but follows a second option to perform this process via ajax and using Json.

var myArray = gvSortingListagemGARs.keys;
var jsonString = JSON.stringify(myArray);
   $.ajax({
        type: "POST",
        url: "/GAR/downloadListaGARsTratadas",
        data: {data : jsonString}, 
        cache: false,

        success: function(){
            alert("OK");
        }
});

Answer 3

I was having a similar problem and found the following link:

https://stackoverflow.com/questions/21288462/c-sharp-mvc-4-passing-javascript-array-in-view-to-controller

See if that helps you:

There is a parameter, called traditional, that you configure in Ajax as true that sends the right javascript array to your controller. traditional : true,

I have an array, called shift, in my javascript that I will pass to my Controller via Ajax.

Shift is an array with days of the week... shift = ["Sunday", "Monday", "Tuesday", 4 more...]

In javascript I have the call via Ajax...

$.ajax({
        url: getBaseUrl() +  "GraphicsReport/FiltraDadosGrafico1",
        type: "POST",
        dataType: "json",
        traditional : true,
        data: {cDataInicial: dataInicial, cDataFinal: dataFinal, cLinha: linha, cTurno: turno, cModelo: modelo},
        cache: false,
        success: function (data) {
            //Faz alguma coisa...
        },
        error: function (data) {
           //Faz alguma coisa...
        }
    });

On my controller I get...

public JsonResult FiltraDadosGrafico1(string cDataInicial, string cDataFinal, string cLinha, Array cTurno, string cModelo)
{
  string retCode = "Success";

  //Faz alguma coisa e retorna um Json

  return Json(new { retorno = retCode } );
}

See if this can help you. For me, solved...

Answer 4

Since I couldn’t solve this problem by returning a list of integers to the controller, I’ll leave an answer here with my solution (although that’s not how I wanted to solve it):

In the javascript function return the array to the controller as it had already done:

function downloadListaGARSTratadas() {
    var myArray = gvSortingListagemGARs.keys;
    window.location.href = "/GAR/downloadListaGARsTratadas?GarsFiltro=" +myArray +"";
}

In the controller instead of receiving an integer array, I sent a string, returning the values as 201,202,203,204:

public FileResult downloadListaGARsTratadas(string GarsFiltro)
{
   var arr = GarsFiltro.Split(',');
}

I made a split for the variable arr and it creates the array