How do I add parameters and the DbContext to a minimal API call?

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How do I add parameters and the DbContext to a minimal API call?

Falanga, Rod, DOH 980

I am working on a Blazor app, which has two projects. One of the Blazor UI and the other is a minimal API project. I've got some endpoints working fine, but now I've got a conundrum. I want to be able to pass a parameter, in this case a Boolen value, plus the DbContext like I've been doing in the other endpoints, in the minimal API. I found a Microsoft Learn course, which works if no minimal API is involved. It's here. This is for .NET 8 (which I've got to use for now). Here's my code in the minimal API:

app.MapGet("/tasks", async ([AsParameters] bool ActiveStatus, TimetrackTestContext context) =>
{
    Response<KeyVaultSecret> kvVal = await GetConnectionString();

    context.Database.SetConnectionString(kvVal.Value.Value);
    var tasks = await context.RTasks.OrderBy(tasks => tasks.Desc).ToListAsync();
    return Results.Ok(tasks);
})
    .WithName("GetTasks")
    .WithOpenApi();

But this has the problem in that the AsParameters attribute is more appropriate for a Blazor UI, rather than using it in a minimal API. However, when I run it in the debugger, its close, but not complete. For example, the ActiveStatus has a value of False, but I'm sure it is always False.

How do I make this work in a minimal API project?

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2 answers

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Answer 1

Bruce (SqlWork.com) 84,086

This pretty covered in the docs

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/minimal-apis/parameter-binding?view=aspnetcore-9.0

As it’s a GET method the proper attribute is [FromQuery] for query string values and [FromService] for injection.

Falanga, Rod, DOH 980 Reputation points

2024-12-03T17:29:50.1766667+00:00
Hi Bruce, I tried to reply to your answer yesterday, but Microsoft Learn would not let me. Today, it is allowing me to respond.

I love your answer but am still having problems implementing it. In fact, it's a vicious circular cycle. I've made changes in accordance with the Microsoft Learn article you reference in one of the endpoints to my Minimal APIs. This is what my endpoint now has, which I'll reference as stage A:

app.MapGet("/tasks/{id}", static (bool active, TimetrackTestContext context) => { Response<KeyVaultSecret> kvVal = GetConnectionString<Response<KeyVaultSecret>>(); context.Database.SetConnectionString(kvVal.Value.Value); var tasks = context.RTasks.OrderBy(tasks => tasks.Desc); return Results.Ok(tasks); }) .WithName("GetTasks") .WithOpenApi();

However, the first line has an error:

The non-generic method 'GetConnectionString()' cannot be used with type arguments

So, I remove "<Response<KeyVaultSecret>>", (Step B) which now gives me the error of:

Cannot implicitly convert type 'System.Threading.Tasks.Task<Azure.Response<Azure.Security.KeyVaul.Secrets.KeyVaultSecret>>'

So, then I look at the code I have for GetConnectionString(), which is now:

static Task<Response<KeyVaultSecret>> GetConnectionString() { string? keyVaultName = Environment.GetEnvironmentVariable("KEY_VAULT_NAME"); var kvUri = $"https://{keyVaultName}.vault.azure.net"; var client = new SecretClient(new Uri(kvUri), new DefaultAzureCredential()); var kvVal = client.GetSecretAsync("Test-ConnectionString"); return kvVal; }

However, the call to client.GetSecretAsync() does return Response<KeyVaultSecret>, which in step B I was told to remove. So, I leave it here, because I have to return a Response<KeyVaultSecret>, and instead I change that call to client.GetSecretAsync to client.GetSecret (it was a mistake I made earlier). This is now Step C:

static Task<Response<KeyVaultSecret>> GetConnectionString() { // This code is in TimetrackTestContext, but commented out string? keyVaultName = Environment.GetEnvironmentVariable("KEY_VAULT_NAME"); var kvUri = $"https://{keyVaultName}.vault.azure.net"; var client = new SecretClient(new Uri(kvUri), new DefaultAzureCredential()); var kvVal = client.GetSecret("Test-ConnectionString"); return kvVal; }

However, that now raises a new error that says:

Cannot implicitly convert type 'Azure.Response<Azure.Security.KeyVault.Secrets.KeyVaultSecret>' to 'System.Threading.Tasks.Task<Azure.Response<Azure.Security.KeyVault.Secrets.KeyVaultSecret>>'

This is within the GetConnectionString. And in the endpoint the new error is:

Cannot implicitly convert type 'System.Threading.Tasks.Task<Azure.Response<Azure.Security.KeyVault.Secrets.KeyVaultSecret>>' to 'Azure.Response<Azure.Security.KeyVault.Secrets.KeyVaultSecret>'

Now, I'm really confused. I want to return kvVal, which is Response<KeyVaultSecert>, and at the same time VS 2022 is telling me that I cannot return that?? So, I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it. I must return it. Then I must not return it.

This is insane!!

I even changed the return value of GetConnectionString to Task<Response<KeyVaultSecret>?> and to Task<Response<KeyVaultSecret>>? None of those work.

So, then I go back to Step A, then to Step B, then to Step C. Then back to Step A, Step B, Step C, Step A, Step B, Step C,Step A, Step B, Step C,Step A, Step B, Step C,Step A, Step B, Step C,Step A, Step B, Step C,Step A, Step B, Step C, ....

This is just getting more insane!!

I've got to break out of this senseless recursion. But, following the instructions, I do not know how I should break out of it.

I'd appreciate more help, please.

xxx

Bruce (SqlWork.com) 84,086

your additional question has nothing to do with min api. it just understand c# types and method return types. one would expect GetConnectionString() to return a string (the connection string). GetConnectionStringAsync() should return a task that returns a string.

static string GetConnectionString()
{
    // This code is in TimetrackTestContext, but commented out
    string? keyVaultName = Environment.GetEnvironmentVariable("KEY_VAULT_NAME");
    var kvUri = $"https://{keyVaultName}.vault.azure.net";
    var client = new SecretClient(new Uri(kvUri), new DefaultAzureCredential());
    var kvVal = client.GetSecret("Test-ConnectionString");

    // return the actual connection string
    return kvVal.Value;
}

then in api:

// not use why the route {id} when it not mapped to a parameter
app.MapGet("/tasks/{id}", static (bool active, TimetrackTestContext context) =>
{
    var connectionString = GetConnectionString();   

    context.Database.SetConnectionString(connectionString);
    var tasks = context.RTasks.OrderBy(tasks => tasks.Desc);
    return Results.Ok(tasks);
})
    .WithName("GetTasks")
    .WithOpenApi();

note: I'd probably use the azure key vault configuration provider:

https://learn.microsoft.com/en-us/aspnet/core/security/key-vault-configuration?view=aspnetcore-9.0

then in the api:

app.MapGet("/tasks/{id}", static (bool active, TimetrackTestContext context) =>
{
    var connectionString = app.Configuration["Test-ConnectionString"];   

    context.Database.SetConnectionString(connectionString);
    var tasks = context.RTasks.OrderBy(tasks => tasks.Desc);
    return Results.Ok(tasks);
})
    .WithName("GetTasks")
    .WithOpenApi();

Falanga, Rod, DOH 980 Reputation points

2024-12-03T20:54:41.0333333+00:00

Thank you, @Bruce (SqlWork.com) for correcting my faulty thinking.

Answer 2

Alex1aq 0

To add parameters and DbContext to a minimal API call in ASP.NET Core, inject the DbContext into the endpoint by including it as a parameter. For example:

app.MapGet("/items/{id}", async (int id, YourDbContext db) => await db.Items.FindAsync(id));

Here, id is a route parameter, and YourDbContext is injected for database access. Ensure YourDbContext is registered in the IServiceCollection in Program.cs using builder.Services.AddDbContext<YourDbContext>().
Source: Rutificador

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How do I add parameters and the DbContext to a minimal API call?

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