ASP.Net MVC 3 - JSON Model binding to array

thanikkal picture thanikkal · Mar 12, 2011 · Viewed 13.6k times · Source

I am on ASP.Net MVC 3, and going by the feature list supported in at, i should be able to get default json model binding working out of the box. However i havent been successful in binding an array/collection from json to the action method parameter. Although I did get simple json object binding working right. Would greatly appreciate if an expert here could tell me what i am doing wrong.

Here is the code:

Server side code first:

//Action Method

 public JsonResult SaveDiscount(IList<Discount> discounts)
    {
       foreach(var discount in discounts)
       {
       ....
       }
    }

//View model

public class Discount
{
    string Sku{get; set;}
    string DiscountValue{get; set;}
    string DiscountType{get; set;}

}

//client side(jquery/js):

    var discount = {};
    var jsondatacoll = [];
    $('#discountgrid tr').each(function () {

        sku = $(this).find("td").eq(1).html();
        discValue = $(this).find('.discval').val();
        discType = $(this).find('.disctype').val();

        discount = { Sku: sku, DiscountType: discType, DiscountValue: discValue};
        jsondatacoll.push(discount);
        }
    })
    if (jsondatacoll.length > 0) {
        var catalogDiscount = JSON.stringify(jsondatacoll);

        $.ajax(
        {
            url: '/url/savediscount',
            type: 'POST',
            data: catalogDiscount,
            dataType: 'json',
            contentType: 'application/json; charset=utf-8',
            success: function (data, textStatus, jqXHR) {
                ...                   
            },
            error: function (objAJAXRequest, strError) {                 
               ...
            }
        }
     );   //ajax
    }

i did check the json payload in fiddler and it look like below:

[
    {"Sku":"sku1","DiscountType":"type1","DiscountValue":"10"},     
    {"Sku":sku2","DiscountType":"type1","DiscountValue":"12"}, 
    {"Sku":"sku3","DiscountType":"type2","DiscountValue":"40"}
]

And on the server side i do see the IList<Discount> discounts has been populated with 3 empty Discount objects - meaning the properties are null but the length of the discounts argument is 3.

Answer

thanikkal picture thanikkal · Mar 15, 2011

As Cresnet Fresh rightly pointed out in the comments to the question the model properties must be marked public.

So modifying Discount class as below resolved this.

public class Discount
{
    public string Sku{get; set;}
    public string DiscountValue{get; set;}
    public string DiscountType{get; set;}

}