Question

I need to pass an array of objects, which contain arrays, from javascript to a MVC actionresult method. Basically I have a KeyValuePair whose key is an array of strings, and I need to pass back a list of these KeyValuePairs. In the code, I have a list of keys I’ve changed, and a JS object that holds key->value pairs. My javascript object that I try to pass back should be the same format as my class. I tried JSONing it as well, but no luck.

Thanks.

public class ChangedItem
{
    public IEnumerable<string> Key { get; set; }
    public int Value { get; set; }

    public ChangedItem()
    {
    }

    public ChangedItem(IEnumerable<string> key, int value)
    {
        Key = key;
        Value = value;
    }
}

[HttpPost]
public ActionResult UpdateResults(IEnumerable<ChangedItem> changedItems)
{
    return RedirectToAction("Index");
}

function getChangedItems() {
    var ChangedItems = new Array();
    for (var i = 0; i < _ChangedItemKeys.length; i++) {
        var ChangedItem = {};
        ChangedItem.Key = _ChangedItemKeys[i];
        ChangedItem.Value = _ChangedItems[_ChangedItemKeys[i]];
        ChangedItems[i] = ChangedItem;
    }
    return ChangedItems;
}

function submitNewVals() {
    $.ajax({
        url: '/Home/UpdateResults',
        type: 'POST',
        dataType: 'json',
        data:
        {
            changedItems: getChangedItems()
        }
    });
}

My request data is detailed below, and I get 6 items in my action result, its just that inside each of those items the key is null and value is 0:

changedItems[0][Key][]:BoxeR
changedItems[0][Key][]:Proleague
changedItems[0][Key][]:Total
changedItems[0][Key][]:2005
changedItems[0][Key][]:Quarter 2
changedItems[0][Key][]:Actual
changedItems[0][Value]:123
changedItems[1][Key][]:BoxeR
changedItems[1][Key][]:Proleague
changedItems[1][Key][]:Team
changedItems[1][Key][]:2005
changedItems[1][Key][]:Quarter 1
changedItems[1][Key][]:Actual
changedItems[1][Value]:123
changedItems[2][Key][]:BoxeR
changedItems[2][Key][]:Proleague
changedItems[2][Key][]:Team
changedItems[2][Key][]:2005
changedItems[2][Key][]:Quarter 1
changedItems[2][Key][]:Estimate
changedItems[2][Value]:123
changedItems[3][Key][]:BoxeR
changedItems[3][Key][]:Proleague
changedItems[3][Key][]:Team
changedItems[3][Key][]:2005
changedItems[3][Key][]:Quarter 2
changedItems[3][Key][]:Actual
changedItems[3][Value]:123
changedItems[4][Key][]:BoxeR
changedItems[4][Key][]:Proleague
changedItems[4][Key][]:Team
changedItems[4][Key][]:2005
changedItems[4][Key][]:Quarter 2
changedItems[4][Key][]:Estimate
changedItems[4][Value]:123

I tried playing around in fiddler and changing the request data format (using .Key[x], .Value), but nothing worked.

Thanks!

Answer 1

The format should be like this:

changedItems[0].Key[0]=BoxeR
changedItems[0].Key[1]=Proleague
changedItems[0].Key[2]=Total
changedItems[0].Key[3]=2005
changedItems[0].Key[4]=Quarter 2
changedItems[0].Key[5]=Actual
changedItems[0].Value=123
...

See ASP.NET Wire Format for Model Binding to Arrays, Lists, Collections, Dictionaries for details.