C#•11mo ago

trying to make an add to cart application in asp.net mvc core

i have been trying for ages to get it to work and am just trying to test it but i have no idea as to why the information isnt getting shown on the view, will have screenshots posted below

23 Replies

mg•11mo ago

$paste

MODiX•11mo ago

If your code is too long, you can post to https://paste.mod.gg/ and copy the link into chat for others to see your shared code!

mg•11mo ago

that site allows you to paste and share multiple files

SkOP•11mo ago

ok 1 sec

mg•11mo ago

but it looks like your issue is that your CartService.GetCartItems() returns the _cartItems field, which you never add anything to Unless you've accessed the AddToCart endpoint beforehand

SkOP•11mo ago

https://paste.mod.gg/szjtdkipisxm

BlazeBin - szjtdkipisxm

A tool for sharing your source code with the world!

mg•11mo ago

👍 looks like CartService got cut off though

SkOP•11mo ago

using AddToCartTest.Models;

namespace AddToCartTest.Services
{
    public class CartService : ICartService
    {
        private readonly List<Cart> _cartItems = new List<Cart>();

        private readonly List<Cart> _allProducts = new List<Cart>
    {
        new Cart { Id = 1, Name = "Apple Vision Pro", Price = 3499.0M },
        new Cart { Id = 2, Name = "Airpod Max", Price = 599.0M },
        new Cart { Id = 3, Name = "Macbook Air M3", Price = 2299.0M },
        new Cart { Id = 4, Name = "Mac Pro", Price = 5199.0M },
        new Cart { Id = 5, Name = "Pro Display XDR", Price = 1399.0M },
        new Cart { Id = 6, Name = "iPhone 15 Pro Max", Price = 899.0M },
        new Cart { Id = 7, Name = "iPad Pro", Price = 599.0M },
        new Cart { Id = 8, Name = "Apple Watch Series 9", Price = 299.0M },
    };

        

        public void AddToCart(Cart product)
        {
            _cartItems.Add(product);
        }

        public List<Cart> GetCartItems()
        {
            return _cartItems.ToList();
        }
    }/*public void AddToCart(int productId)
        {
            var productToAdd = _allProducts.FirstOrDefault(p => p.Id == productId);
            if (productToAdd != null)
            {
                _cartItems.Add(productToAdd);
            }
        }

        public List<Cart> GetCartItems()
        {
            return _cartItems.ToList();
        }*/

        /*public void AddToCart(Cart product)
        {
            _cartItems.Add(product);
        }

        public List<Cart> GetCartItems()
        {
            return _cartItems;
        }*/

}

using AddToCartTest.Models;

namespace AddToCartTest.Services
{
    public class CartService : ICartService
    {
        private readonly List<Cart> _cartItems = new List<Cart>();

        private readonly List<Cart> _allProducts = new List<Cart>
    {
        new Cart { Id = 1, Name = "Apple Vision Pro", Price = 3499.0M },
        new Cart { Id = 2, Name = "Airpod Max", Price = 599.0M },
        new Cart { Id = 3, Name = "Macbook Air M3", Price = 2299.0M },
        new Cart { Id = 4, Name = "Mac Pro", Price = 5199.0M },
        new Cart { Id = 5, Name = "Pro Display XDR", Price = 1399.0M },
        new Cart { Id = 6, Name = "iPhone 15 Pro Max", Price = 899.0M },
        new Cart { Id = 7, Name = "iPad Pro", Price = 599.0M },
        new Cart { Id = 8, Name = "Apple Watch Series 9", Price = 299.0M },
    };

        

        public void AddToCart(Cart product)
        {
            _cartItems.Add(product);
        }

        public List<Cart> GetCartItems()
        {
            return _cartItems.ToList();
        }
    }/*public void AddToCart(int productId)
        {
            var productToAdd = _allProducts.FirstOrDefault(p => p.Id == productId);
            if (productToAdd != null)
            {
                _cartItems.Add(productToAdd);
            }
        }

        public List<Cart> GetCartItems()
        {
            return _cartItems.ToList();
        }*/

        /*public void AddToCart(Cart product)
        {
            _cartItems.Add(product);
        }

        public List<Cart> GetCartItems()
        {
            return _cartItems;
        }*/

}

this is the full code, i just cut out the commeted bit

mg•11mo ago

it's best to just share your code exactly as it is

SkOP•11mo ago

sure, mb

mg•11mo ago

because that's the code that's running but anyway, are you sure there are actually elements in _cartItems when you access it?

SkOP•11mo ago

no, how would be the best way to assign my items in CartServices to _cartItems, at the moment im just trying to test it to make sure its working then i will be able to connect it so when a buttons pressed its added to cart

mg•11mo ago

You can initialize the list with some starting elements just like you do for _allProducts

SkOP•11mo ago

ah okay tyyyyy, ill try that wehn im back ive initialized it but even just trying to test using

 public IActionResult AddToCart()
 {
      // For demonstration purposes, manually add a product to the cart
 var productToAdd = new Cart
 {
     Id = 999, // Choose a unique ID
     Quantity = 3,
     Price = 99.0M,
     Name = "Manually Added Product",
     // Add other properties as needed
 };
     
 _cartService.AddToCart(productToAdd);

 return RedirectToAction("Index");
 }

 public IActionResult AddToCart()
 {
      // For demonstration purposes, manually add a product to the cart
 var productToAdd = new Cart
 {
     Id = 999, // Choose a unique ID
     Quantity = 3,
     Price = 99.0M,
     Name = "Manually Added Product",
     // Add other properties as needed
 };
     
 _cartService.AddToCart(productToAdd);

 return RedirectToAction("Index");
 }

I cant get it to work, so im not sure what else to do because that code should add an item to the cart but it still just displays an empty cart

mg•11mo ago

what code @Sk oh sorry ok right, but are you actually navigating to /AddToCart? And is CartService a singleton?

SkOP•11mo ago

yeah but it just sends me back to /Cart - like i will put in localhost/Cart/Addtocart and i just get sent bacm to localhost/cart what do you mean? sorry if thats a stupid question haha

mg•11mo ago

nah not at all. it's not obvious the way that your controller actually gets an instance of ICartService is through a service provider presumably at some point you wrote services.AddX<ICartService, CartService>(), right? where X is Singleton, Scoped, or Transient

SkOP•11mo ago

ah, i have it as transient in program.cs?

using AddToCartTest.Data;
using AddToCartTest.Services;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllersWithViews();
builder.Services.AddDbContext<ApplicationDbContext>(options =>
{
    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection"));
});
builder.Services.AddSession(options =>
{
    options.IdleTimeout = TimeSpan.FromMinutes(30);
    options.Cookie.HttpOnly = true;
});
builder.Services.AddTransient<ICartService, CartService>();


var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Shop}/{action=Index}/{id?}");

app.UseSession();

app.Run();

using AddToCartTest.Data;
using AddToCartTest.Services;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllersWithViews();
builder.Services.AddDbContext<ApplicationDbContext>(options =>
{
    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection"));
});
builder.Services.AddSession(options =>
{
    options.IdleTimeout = TimeSpan.FromMinutes(30);
    options.Cookie.HttpOnly = true;
});
builder.Services.AddTransient<ICartService, CartService>();


var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Shop}/{action=Index}/{id?}");

app.UseSession();

app.Run();

this is my program.cs

mg•11mo ago

Yeah that'll do it Those are called service lifetimes Transient means it creates a new instance of the service every time it's asked for Scoped is a little different; in this case it's once per request Singleton is created once for the entire lifetime of the program

SkOP•11mo ago

which is best to use? for this scenario

mg•11mo ago

So because you registered it as transient, it's creating one CartService when you add to the cart, and then creating an entirely new one when you get the cart items In this case, singleton Because you want the state to persist across all the requests

SkOP•11mo ago

YESSSSSSSSS. getting somewhere, tysm for being patient and so helpful, it means alot!

mg•11mo ago

of course!

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trying to make an add to cart application in asp.net mvc core