Question

I would like to dynamically add fields to an ASP.NET MVC form with JQuery.

Example:

<script language="javascript" type="text/javascript">
    var widgets;

    $(document).ready(function() {
        widgets = 0;
        AddWidget();
    });

    function AddWidget() {
        $('#widgets').append("<li><input type='text' name='widget" + widgets + "'/></li>");
        widgets++;
    }
</script>

<ul id="widgets">
</ul>

This works, but I was going to manually iterate the form values in the controller:

[AcceptVerbs("Post")]
public ActionResult AddWidget(FormCollection form)
{
    foreach (string s in form)
    {
        string t = form[s];
    }

    return RedirectToAction("ActionName");
}

But it occurred to me when I send the user back to the Get Action in the Controller I will have to set the FormData with the values entered and then iteratively add the widgets with <% scripting.

What is the est way to do this in the current release (5 I believe)?

Answer 1

My solution could be something like this (pseudo-code):

<script language="javascript" type="text/javascript">
    var widgets;

    $(document).ready(function() {
        widgets = 0;
        <% for each value in ViewData("WidgetValues") %>
             AddWidget(<%= value %>);
        <% next %>
    });

    function AddWidget( value ) {
        $('#widgets').append("<li><input type='text' name='widget" + widgets + 
                             "'>" + value + "</input></li>");
        widgets++;
    }
</script>

<ul id="widgets">
</ul>

And in the controller:

[AcceptVerbs("Post")]
public ActionResult AddWidget(FormCollection form)
{
    dim collValues as new Collection;
    foreach (string s in form)
    {
        string t = form[s];
        collValues.add( t )
    }
    ViewData("WidgetValues") = collValues;
    return RedirectToAction("ActionName");
}

You can work out the details later
(sorry for mixing VB with C#, I’m a VB guy)