Alex
Alex
PostsComments
CC#
Created by Alex on 7/2/2024 in #help
Recommend book/source
Hi, I know how to program small applications, but I want to learn how to build programs like file system explorer, task manager or notepad. Is there any book or source that teaches you system/application design and building with examples I mentioned about? I want to understand how to build application right way, and how they function.
8 replies
CC#
Created by Alex on 6/28/2024 in #help
✅ Refresh Token + JWT + Identity
Hi! I can't find a way how to implement refresh token part with Identity. Most tutorials online don't use Identity and write their own implementation. Should I extend identity user or is there a better way? I want to learn how it can be done the right way.
6 replies
CC#
Created by Alex on 6/28/2024 in #help
✅ Refresh token for Identity
Hi! What's the correct way to implement refresh token in AspNetCore Identity? Can I use .SetAuthenticationTokenAsync() for this purpose? I want to use in refresh-token endpoint to create new JsonWebToken after it expires.
1 replies
CC#
Created by Alex on 6/27/2024 in #help
✅ Web API redirect back to client
I have a GET route that handles external authentication. On the client I have anchor <a href="myapi:8080/sign-in/external/Google">Google</a> to sign in with Google. If authentication is successful I want to return cookie (I'll change it later) and redirect back to client. I have one option to provide returnUrl but I'm not sure if it is a right solution. How can I do it? 
[HttpGet("sign-in/external/{provider}")]
public IActionResult External([FromRoute] string provider)
{
    AuthenticationProperties props =
        _signInManager.ConfigureExternalAuthenticationProperties(provider, "/api/Accounts/external-callback");

    return new ChallengeResult(provider, props);
}

[HttpGet("external-callback")]
public async Task<IActionResult> ExternalCallback()
{
...
// if authentication is success
return Ok();
}
[HttpGet("sign-in/external/{provider}")]
public IActionResult External([FromRoute] string provider)
{
    AuthenticationProperties props =
        _signInManager.ConfigureExternalAuthenticationProperties(provider, "/api/Accounts/external-callback");

    return new ChallengeResult(provider, props);
}

[HttpGet("external-callback")]
public async Task<IActionResult> ExternalCallback()
{
...
// if authentication is success
return Ok();
}
  <AnchorButton
    href={`${import.meta.env.VITE_API_URL}/accounts/sign-in/external/Google`}
  >Google</AnchorButtom>
  <AnchorButton
    href={`${import.meta.env.VITE_API_URL}/accounts/sign-in/external/Google`}
  >Google</AnchorButtom>
1 replies
CC#
Created by Alex on 6/25/2024 in #help
✅ How to get Options from DI
I configured options for google authentication CliendId and ClientSecret. 
builder.Services.ConfigureOptions<GoogleOptions>();
builder.Services.ConfigureOptions<GoogleOptions>();
Here I want to get them from ServiceProvider but I don't know how. Should I create ServiceProvider var provider = builder.Services.BuildServiceProvider();? 
builder.Services.AddAuthentication()
    .AddGoogle((options) =>
    {
        options.ClientId = "";
        options.ClientSecret = "";
    });
builder.Services.AddAuthentication()
    .AddGoogle((options) =>
    {
        options.ClientId = "";
        options.ClientSecret = "";
    });
14 replies
CC#
Created by Alex on 6/17/2024 in #help
What's wrong with my LINQ expression?
Hi! I'm trying to get data using LINQ expressions below. I use Sqlite 
public async Task OnGetAsync()
{
    var now = DateTimeOffset.Now;

    LockedOutUsers =
        await _userManager
            .Users
            .Where(u => u.LockoutEnd != null && u.LockoutEnd > now)
            .OrderBy(u=>u.Email)
            .ToListAsync();

    OtherUsers = await _userManager
        .Users.Where(u => u.LockoutEnd == null || u.LockoutEnd <= now)
        .OrderBy(u => u.Email)
        .ToListAsync();
}
public async Task OnGetAsync()
{
    var now = DateTimeOffset.Now;

    LockedOutUsers =
        await _userManager
            .Users
            .Where(u => u.LockoutEnd != null && u.LockoutEnd > now)
            .OrderBy(u=>u.Email)
            .ToListAsync();

    OtherUsers = await _userManager
        .Users.Where(u => u.LockoutEnd == null || u.LockoutEnd <= now)
        .OrderBy(u => u.Email)
        .ToListAsync();
}
But I'm getting exception 
InvalidOperationException: The LINQ expression 'DbSet<IdentityUser>() .Where(i => i.LockoutEnd != null && i.LockoutEnd.Value > __now_0)' could not be translated.
InvalidOperationException: The LINQ expression 'DbSet<IdentityUser>() .Where(i => i.LockoutEnd != null && i.LockoutEnd.Value > __now_0)' could not be translated.
56 replies
CC#
Created by Alex on 6/14/2024 in #help
✅ Malformed input: 321 is an invalid input length
I'm working with Asp.Net Core Identity. I use GeneratePasswordResetTokenAsync(user) to generate token and encode it with WebEncoders.Base64UrlEncode(Encoding.UTF8.GetBytes(token));. Next I decode encoded token with Encoding.UTF8.GetString(WebEncoders.Base64UrlDecode(encodedToken)) and get exception: 
An unhandled exception occurred while processing the request.
FormatException: Malformed input: 321 is an invalid input length.
Microsoft.AspNetCore.WebUtilities.WebEncoders.GetNumBase64PaddingCharsToAddForDecode(int inputLength)
An unhandled exception occurred while processing the request.
FormatException: Malformed input: 321 is an invalid input length.
Microsoft.AspNetCore.WebUtilities.WebEncoders.GetNumBase64PaddingCharsToAddForDecode(int inputLength)
How can I fix my problem?
1 replies
CC#
Created by Alex on 5/19/2024 in #help
✅ Store data for the game
How can I efficiently store lines for the picture player draws? Each line contains color, line width and points (x,y). I have a group object that will have array of drawn linesбword players need to guess and state "drawing","choosing word", "idle". I need the data for players who join after the round started. I need the data between signalR calls
1 replies
CC#
Created by Alex on 5/16/2024 in #help
✅ SignalR client to client communication (chat)
Is it correct that I can't send messages from client to client directly using SignalR? Do I need to send http POST request to endpoint, then inside endpoint I get IHubContext and execute method ReceiveChatMessage? (Client code) 
 
 const onSubmit = (
    values: SubmitMessageSchema,
    reset: UseFormReset<SubmitMessageSchema>
  ) => {
             // METHOD USERNAME MESSAGE
    connection?.send("ReceiveChatMessage", "Alex", values.text);
    reset();
  };
 
 const onSubmit = (
    values: SubmitMessageSchema,
    reset: UseFormReset<SubmitMessageSchema>
  ) => {
             // METHOD USERNAME MESSAGE
    connection?.send("ReceiveChatMessage", "Alex", values.text);
    reset();
  };
4 replies
CC#
Created by Alex on 5/15/2024 in #help
✅ what's the difference?
What's the difference between sending message to signalR endpoint directly and sending post to controller and execute it hubcinnection.sendasync method inside of it? I want to build game project based on signalr, one person draws the picture other guess what is it by typing it in chat. Can I use only one connection for both sending drawn pixels and chat messages? Should I send chat messages directly to signalR hub of to the post route of controller?
4 replies
CC#
Created by Alex on 5/12/2024 in #help
Storage for http request routes
In the method to search route I'll provide "Method" and "Path". Is there a better way to store routes that Dictionary<string,Dictionary<string,delegate>>?
1 replies
CC#
Created by Alex on 5/11/2024 in #help
How can I accept multiple clients?
I want to write my own http server using TCP and System.Net.Sockets. Here is my code: 
using System.Net;
using System.Net.Sockets;
using System.Text;

const string ipAddress = "127.0.0.1";
const int port = 27015;

try
{

    // create socket
    Socket listenSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream,ProtocolType.Tcp);

    // bind ip address

    IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Parse(ipAddress),port);

    listenSocket.Bind(ipEndPoint);

    // Listen
    listenSocket.Listen();

    Console.WriteLine($"listening on http://{ipAddress}:{port}");

    Socket acceptSocket = await listenSocket.AcceptAsync();



    byte[] buffer = new byte[1024];
    int bytesReceived = await acceptSocket.ReceiveAsync(buffer, SocketFlags.None);

    string message = Encoding.UTF8.GetString(buffer, 0, bytesReceived);

    Console.WriteLine(message);


    string response = "HTTP/1.1 200 OK\r\nContent - Type: text/html\r\n\r\n{ \"msg\"=\"Hello world!\"}";


    await acceptSocket.SendAsync(Encoding.UTF8.GetBytes(response, 0, response.Length));

    acceptSocket.Close();

    listenSocket.Close();
}
catch (Exception ex)
{
    Console.WriteLine($"[{ex.GetType()}]: {ex.Message}");
}
using System.Net;
using System.Net.Sockets;
using System.Text;

const string ipAddress = "127.0.0.1";
const int port = 27015;

try
{

    // create socket
    Socket listenSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream,ProtocolType.Tcp);

    // bind ip address

    IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Parse(ipAddress),port);

    listenSocket.Bind(ipEndPoint);

    // Listen
    listenSocket.Listen();

    Console.WriteLine($"listening on http://{ipAddress}:{port}");

    Socket acceptSocket = await listenSocket.AcceptAsync();



    byte[] buffer = new byte[1024];
    int bytesReceived = await acceptSocket.ReceiveAsync(buffer, SocketFlags.None);

    string message = Encoding.UTF8.GetString(buffer, 0, bytesReceived);

    Console.WriteLine(message);


    string response = "HTTP/1.1 200 OK\r\nContent - Type: text/html\r\n\r\n{ \"msg\"=\"Hello world!\"}";


    await acceptSocket.SendAsync(Encoding.UTF8.GetBytes(response, 0, response.Length));

    acceptSocket.Close();

    listenSocket.Close();
}
catch (Exception ex)
{
    Console.WriteLine($"[{ex.GetType()}]: {ex.Message}");
}
How can I accept multiple sockets? Should I create new Thread for each socket (I'll add while loop later)? Also, should I store threads somewhere to finish them after I handled request? Maybe you can give any other advices on this topic
26 replies
CC#
Created by Alex on 5/8/2024 in #help
Serve SPA (React) in ASP.NET web API
No description
1 replies
CC#
Created by Alex on 5/7/2024 in #help
How to create first user (Admin)?
I have backend, users can create accounts, each account has role - admin or user. I want the first account to be Admin. Should I create it during database seeding or every time user register their account I check if it's first user and give him admin role? Or is there a better way? Aslo accounts must be verified to log in to it and only admin users can verify other user account.
8 replies
CC#
Created by Alex on 5/4/2024 in #help
✅ How to handle errors in services/controllers
Hi! I do most of work in services and then call the method in the controller. What's the proper way to handle errors that occur in service? I need return error to the frontend (the error model must be consistent). Is it fine to throw error in the services or is there a better way? Here is example of AccountService method 
public async Task RegisterAsync(RegisterDto dto)
{
    IdentityUser? foundUser = await _userManager.FindByEmailAsync(dto.Email);

    if (foundUser != null)
    {
        throw new Exception($"Email '{dto.Email}' is already registered");
    }

    IdentityUser userToCreate = new IdentityUser
    {
        UserName = dto.Email,
        Email = dto.Email
    };

    IdentityResult result = await _userManager.CreateAsync(userToCreate, dto.Password);

    if (!result.Succeeded)
    {
        throw new Exception($"Failed to create user:{string.Join(',', result.Errors.Select(e => e.Description))}");
    }
}
public async Task RegisterAsync(RegisterDto dto)
{
    IdentityUser? foundUser = await _userManager.FindByEmailAsync(dto.Email);

    if (foundUser != null)
    {
        throw new Exception($"Email '{dto.Email}' is already registered");
    }

    IdentityUser userToCreate = new IdentityUser
    {
        UserName = dto.Email,
        Email = dto.Email
    };

    IdentityResult result = await _userManager.CreateAsync(userToCreate, dto.Password);

    if (!result.Succeeded)
    {
        throw new Exception($"Failed to create user:{string.Join(',', result.Errors.Select(e => e.Description))}");
    }
}
10 replies
CC#
Created by Alex on 5/4/2024 in #help
✅ redirect url is not passed to request
No description
1 replies
CC#
Created by Alex on 5/3/2024 in #help
✅ Challenge does not redirect
        [HttpPost("sign-in/external")]
        public IActionResult SignInExternal([FromQuery] string provider ="Google", [FromQuery] string returnUrl = "https://localhost:8080/api/identity/sign-in/google")
        {
            AuthenticationProperties properties = _identityService.SignInExternal(provider,returnUrl);

            return Challenge(properties,provider);
        }
        [HttpPost("sign-in/external")]
        public IActionResult SignInExternal([FromQuery] string provider ="Google", [FromQuery] string returnUrl = "https://localhost:8080/api/identity/sign-in/google")
        {
            AuthenticationProperties properties = _identityService.SignInExternal(provider,returnUrl);

            return Challenge(properties,provider);
        }
What can be the reason?
4 replies
CC#
Created by Alex on 5/3/2024 in #help
✅ Google External sign in using Identity
I want to learn how to implement a google external sign-in route (and Identity in general) in my ASP.NET Web API but I can't find any recent tutorial on that topic. Microsoft's official tutorial is for RazorPages only and tells you to add AddAuthentication().AddGoogle() and everything should work. I want to create it for Web API because I need it for the React front end. I found a few tutorials but they are 3-5 years old. Can you suggest any tutorials on this topic or for Identity in Web API in general? Also, I used it about 2 years ago and I had to create routes like register and login by myself using userManager and signInManager etc, now the tutorial suggests using MapIdentityApi which serves pre-made routes which I can't modify. Is it a new way to use Identity or it's just made for simplicity in tutorial only?
4 replies
CC#
Created by Alex on 4/30/2024 in #help
CRUD for complex objects
No description
16 replies
CC#
Created by Alex on 4/27/2024 in #help
✅ Run PuppeteerSharp in Docker Container
I have an endpoint that creates PDFs using PuppeteerSharp. I work fine locally because it can automatically download Chromium. The opposite in the Docker Container, it tells me that no executable chromium found. Is there a way to pre download? 
FROM mcr.microsoft.com/dotnet/sdk:8.0 as build
WORKDIR /App

COPY . ./

RUN dotnet restore
RUN dotnet publish -c Release -o out

FROM mcr.microsoft.com/dotnet/aspnet:8.0
WORKDIR /App
COPY --from=build /App/out .
ENTRYPOINT ["dotnet", "Vocabify.API.dll"]
FROM mcr.microsoft.com/dotnet/sdk:8.0 as build
WORKDIR /App

COPY . ./

RUN dotnet restore
RUN dotnet publish -c Release -o out

FROM mcr.microsoft.com/dotnet/aspnet:8.0
WORKDIR /App
COPY --from=build /App/out .
ENTRYPOINT ["dotnet", "Vocabify.API.dll"]
17 replies