case insensitive parameter binding in minimal api and swagger dokumentation

Question

I have a c# .net 8 minimal api witch takes as a parameter an enum:

app.MapGet("/{id}/attachments/{category}/{attachmentId}", async (
            Guid id,
            AttachmentCategory category,
            string attachmentId) => {
                ...
            })

Enum:

public enum AttachmentCategory
{
    Documents,
    Photos
}

I am using System.Text.Json

Serialization:

options.SerializerOptions.Converters.Add(new JsonStringEnumConverter(JsonNamingPolicy.CamelCase));

works:

https://localhost:1234/api/v1/item/b9c10df0-c974-4876-a3fa-d4b5e8140929/attachments/Documents/3abd9b3b-97e9-4668-b4b3-50cbcdac0220.pdf

does not work:

https://localhost:1234/api/v1/item/b9c10df0-c974-4876-a3fa-d4b5e8140929/attachments/documents/3abd9b3b-97e9-4668-b4b3-50cbcdac0220.pdf

Can I make lower case work? mybe both?

Problem 2: The enum parameter shows up in swagger as a string not as an enum

Is a IDocumentFilter the only way to fix that?

Answer 1

To fix problem2,you may try:

builder.Services.Configure<Microsoft.AspNetCore.Http.Json.JsonOptions>(options =>
{
    options.SerializerOptions.Converters.Add(new System.Text.Json.Serialization.JsonStringEnumConverter());
});
builder.Services.Configure<Microsoft.AspNetCore.Mvc.JsonOptions>(options =>
{
    options.JsonSerializerOptions.Converters.Add(new System.Text.Json.Serialization.JsonStringEnumConverter());
});

.....

app.MapGet("/{id}/attachments/{category}/{attachmentId}", (
            Guid id,
            [FromRoute] AttachmentCategory category,
            string attachmentId) =>
{
    .....
})
.WithOpenApi();

To fix problem 1:

app.MapGet("/{id}/attachments/{category}/{attachmentId}", (Guid id, [FromRoute]Category category, string attachmentId) =>
{
    return attachmentId;
})
.WithOpenApi();

public class Category
{
    [FromRoute]
    public AttachmentCategory category { get; set; }

    public static bool TryParse(string? value, IFormatProvider? provider,
                                out Category? categoryval)
    {

       
        
        var success= Enum.TryParse<AttachmentCategory>(value,
                                    ignoreCase: true, out var categoryenumval);
        if(success)
        {
            categoryval = new Category() { category = categoryenumval };
            return true;
        }
        else
        {
            categoryval = null;
            return false;
        }
        
    }
    
}

accroding to this document,related issue on github

but in this senaro,you need a filter to relapce category schema(if you need ,i will deliever it to you tomorrow)