quantity field on category page?

Hi i was just wondering if anyone had an example of how to add a quantity field on the product listing page for a category

What i was trying to do was a tabular style category page where each product is a row and has a thumbnail image, qty, and add to cart button so the user doesn't have to drill down into the product detail page but can order more than 1 of a given product if they wish.. just wondering if that was possible?
Cheers,
Tom

Yes you can do that, but please bear in mind that it is not so straightforward. I will give you some basic guidelines with code. But you should look to make this as a plugin rather than change the core source code.

1.  In the _ProductBox.cshtml in your theme add some markup for the textbox:

@if (!Model.ProductPrice.DisableBuyButton)
        {                          
            <table width="133" border="0" cellspacing="0" cellpadding="0">
                <tr>
                    <td width="35">
                        @*@Html.TextBoxFor(model => model.EnteredQuantity, new { @class = "inputNumber" })*@
      @Html.TextBox("EnteredQuantity", null, new { @class = "inputNumber" })
                    </td>
                    <td>
                        @*<input type="button" value="@T("ShoppingCart.AddToCart")" class="addBasket" onclick="setLocation('@(@Url.RouteUrl("AddProductToCart", new { productIdAndEnteredQuantity = string.Format("{0}-{1}", Model.Id, Model.EnteredQuantity) }))')" />*@
      <input type="button" value="@T("ShoppingCart.AddToCart")" class="addBasket" data-productId="@Model.Id"/>
                    </td>
                </tr>
            </table>
        }

Note the data-productId attribute in the button control. This attribute will be used in the next step.

2. Add some javascript to your Category template so that the quantity entered into the textbox can be passed to the controller action, which adds the product to the basket. The code could look something like this:

script type="text/javascript">

    $(document).ready(function () {

        $("input.addBasket").click(function () {

            var productId = $(this).attr("data-productId");
            var quantity = $(this).parent().siblings().find("#EnteredQuantity").val();
            var productIdAndEnteredQuantity = productId + "-" + quantity;
            var addProductToCartUrl = "@Url.RouteUrl("AddProductToCart")";
            addProductToCartUrl = addProductToCartUrl + "/" + productIdAndEnteredQuantity;
            setLocation(addProductToCartUrl);
        });

    });

</script>

What this code is doing is constructing a productid-quantity string and appending it to the url for the add to basket action.

3. In the Nop.Web.Infrastructure.RouteProvider edit the following route.

routes.MapLocalizedRoute("AddProductToCart",
                            "cart/addproduct/{productIdAndEnteredQuantity}",
                            new { controller = "ShoppingCart", action = "AddProductToCart", productIdAndEnteredQuantity = string.Empty },
                            new[] { "Nop.Web.Controllers" });

Please note that ideally you should register this route in a plugin and not change the core RouteProvider.

4. Add the following method to the Nop.Web.Controllers.ShoppingCartController class:

public ActionResult AddProductToCart(string productIdAndEnteredQuantity)
        //public ActionResult AddProductToCart(int productId, int enteredQuantity)
        {
            int productId = -1;
            int enteredQuantity = -1;

            var elements = productIdAndEnteredQuantity.Split('-');
            if (elements.Count() < 2)
                return RedirectToAction("Index", "Home");
            if (!int.TryParse(elements[0], out productId))
                return RedirectToAction("Index", "Home");
            if (!int.TryParse(elements[1], out enteredQuantity))
                return RedirectToAction("Index", "Home");

            var product = _productService.GetProductById(productId);
            if (product == null || enteredQuantity <= 0)
                return RedirectToAction("Index", "Home");

            int productVariantId = 0;
            if (_shoppingCartService.DirectAddToCartAllowed(productId, out productVariantId))
            {
                var productVariant = _productService.GetProductVariantById(productVariantId);
                var addToCartWarnings = _shoppingCartService.AddToCart(_workContext.CurrentCustomer,
                    productVariant, ShoppingCartType.ShoppingCart,
                    string.Empty, decimal.Zero, enteredQuantity, true);
                if (addToCartWarnings.Count == 0)
                    return RedirectToRoute("ShoppingCart");
                else
                    return RedirectToRoute("Product", new { productId = product.Id, SeName = product.GetSeName() });
            }
            else
                return RedirectToRoute("Product", new { productId = product.Id, SeName = product.GetSeName() });
        }

Again this change should be done from a plugin not directly to the ShoppingCartController class.

This is it!
This is an implementation which if extracted to a plugin could be quite a good solution.

Hope you manage to implement it.

Thanks so much for such a detailed post!!
What is the @T in the razor? Ie what does t refer to?

Ate there any examples on how to create a plugin I last used nop 1.8 and looks like alot has changed!

T is not specific to razor it is specific to nopCommerce.
It is just a property on the base page and this property returns a delegate function, which is used to get localized resources from the database:

Have a look at:

Nop.Web.Framework.ViewEngines.Razor.WebViewPage

As to creating a plugin you might want to check the documentation:

https://www.nopcommerce.com/documentation.aspx

Hope you will find it useful.

I am new to nop commerce and have installed version 3.90. I want to add quantity field on category page and tried solution posted here but its giving me error on ShoppingCartController.cs :
"Nop.Services.Orders.IShoppingCartService does not contain a definition for DirectAddToCartAllowed "
Please let me know how can I add Quantity textbox to category page and add to cart with that quantity without going to detail page.