This blog post contains a step by step guide illustrating how to achieve that.
UPDATE:
As requested in the comments section I am illustrating step by step how to adapt the aforementioned article to your scenario.
Model:
public class MyOtherModelObject
{
public string Name { get; set; }
public string Description { get; set; }
}
public class MyModelObject
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public List<MyOtherModelObject> OtherModelObjects { get; set; }
}
Controller:
public class HomeController : Controller
{
public ActionResult Index()
{
var model = new MyModelObject
{
Id = 1,
Name = "the model",
Description = "some desc",
OtherModelObjects = new[]
{
new MyOtherModelObject { Name = "foo", Description = "foo desc" },
new MyOtherModelObject { Name = "bar", Description = "bar desc" },
}.ToList()
};
return View(model);
}
[HttpPost]
public ActionResult Index(MyModelObject model)
{
return Content("Thank you for submitting the form");
}
public ActionResult BlankEditorRow()
{
return PartialView("EditorRow", new MyOtherModelObject());
}
}
View (~/Views/Home/Index.cshtml):
@model MyModelObject
@using(Html.BeginForm())
{
@Html.HiddenFor(x => x.Id)
<div>
@Html.LabelFor(x => x.Name)
@Html.EditorFor(x => x.Name)
</div>
<div>
@Html.LabelFor(x => x.Description)
@Html.TextBoxFor(x => x.Description)
</div>
<hr/>
<div id="editorRows">
@foreach (var item in Model.OtherModelObjects)
{
@Html.Partial("EditorRow", item);
}
</div>
@Html.ActionLink("Add another...", "BlankEditorRow", null, new { id = "addItem" })
<input type="submit" value="Finished" />
}
Partial (~/Views/Home/EditorRow.cshtml):
@model MyOtherModelObject
<div class="editorRow">
@using (Html.BeginCollectionItem("OtherModelObjects"))
{
<div>
@Html.LabelFor(x => x.Name)
@Html.EditorFor(x => x.Name)
</div>
<div>
@Html.LabelFor(x => x.Description)
@Html.EditorFor(x => x.Description)
</div>
<a href="#" class="deleteRow">delete</a>
}
</div>
Script:
$('#addItem').click(function () {
$.ajax({
url: this.href,
cache: false,
success: function (html) {
$('#editorRows').append(html);
}
});
return false;
});
$('a.deleteRow').live('click', function () {
$(this).parents('div.editorRow:first').remove();
return false;
});
Remark: the BeginCollectionItem custom helper is taken from the same article I've linked to, but I am providing it here for completeness sake of the answer:
public static class HtmlPrefixScopeExtensions
{
private const string idsToReuseKey = "__htmlPrefixScopeExtensions_IdsToReuse_";
public static IDisposable BeginCollectionItem(this HtmlHelper html, string collectionName)
{
var idsToReuse = GetIdsToReuse(html.ViewContext.HttpContext, collectionName);
string itemIndex = idsToReuse.Count > 0 ? idsToReuse.Dequeue() : Guid.NewGuid().ToString();
// autocomplete="off" is needed to work around a very annoying Chrome behaviour whereby it reuses old values after the user clicks "Back", which causes the xyz.index and xyz[...] values to get out of sync.
html.ViewContext.Writer.WriteLine(string.Format("<input type=\"hidden\" name=\"{0}.index\" autocomplete=\"off\" value=\"{1}\" />", collectionName, html.Encode(itemIndex)));
return BeginHtmlFieldPrefixScope(html, string.Format("{0}[{1}]", collectionName, itemIndex));
}
public static IDisposable BeginHtmlFieldPrefixScope(this HtmlHelper html, string htmlFieldPrefix)
{
return new HtmlFieldPrefixScope(html.ViewData.TemplateInfo, htmlFieldPrefix);
}
private static Queue<string> GetIdsToReuse(HttpContextBase httpContext, string collectionName)
{
// We need to use the same sequence of IDs following a server-side validation failure,
// otherwise the framework won't render the validation error messages next to each item.
string key = idsToReuseKey + collectionName;
var queue = (Queue<string>)httpContext.Items[key];
if (queue == null)
{
httpContext.Items[key] = queue = new Queue<string>();
var previouslyUsedIds = httpContext.Request[collectionName + ".index"];
if (!string.IsNullOrEmpty(previouslyUsedIds))
foreach (string previouslyUsedId in previouslyUsedIds.Split(','))
queue.Enqueue(previouslyUsedId);
}
return queue;
}
private class HtmlFieldPrefixScope : IDisposable
{
private readonly TemplateInfo templateInfo;
private readonly string previousHtmlFieldPrefix;
public HtmlFieldPrefixScope(TemplateInfo templateInfo, string htmlFieldPrefix)
{
this.templateInfo = templateInfo;
previousHtmlFieldPrefix = templateInfo.HtmlFieldPrefix;
templateInfo.HtmlFieldPrefix = htmlFieldPrefix;
}
public void Dispose()
{
templateInfo.HtmlFieldPrefix = previousHtmlFieldPrefix;
}
}
}
