c# - 如何有选择地将 OperationFilter 添加到 Swagger 中的 API 端点？

Question

我有以下 IOperationFilter 类，它实现了我的 API 应用程序中某些端点所需的身份验证 header :

public class AuthenticationHeadersFilter : IOperationFilter
{
    public void Apply(OpenApiOperation operation, OperationFilterContext context)
    {
        if (operation.Parameters == null)
            operation.Parameters = new List<OpenApiParameter>();

        operation.Parameters.Add(new OpenApiParameter
            {
                Name = "AccountName",
                In = ParameterLocation.Header,
                Required = true
            });

        operation.Parameters.Add(new OpenApiParameter
            {
                Name = "ApiKey",
                In = ParameterLocation.Header,
                Required = true
            });
    }
}

通过 Startup.cs 的 ConfigureServices 方法将以上内容添加到我的应用程序的 Swagger UI 中:

services.AddSwaggerGen(c =>
{
    // ...
    // other Swagger configurations
    // ... 
    c.OperationFilter<AuthenticationHeadersFilter>();
});

这很好用，但是我现在也有一些端点，我希望由 Swagger 记录/显示这些端点，但应该完全公开访问而无需用户提供 AccountName 和 ApiKey 作为其 API 请求中的 header 。我怎样才能做到这一点？

我找到了 this Stack Overflow answer ，但不确定是否可以根据我的目的进行调整。我找不到任何关于 OperationFilterContext 类的有用文档。

非常感谢任何帮助。

Answer 1

可能的解决方案是拥有这样的属性

using System;

namespace some.namespace
{
    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Class)]
    public class SkipAuthenticationHeadersAttribute : Attribute
    {
    }
}

并像这样在 swagger AuthenticationHeadersFilter 中使用它:

using System.Linq;
using Microsoft.OpenApi.Any;
using Microsoft.OpenApi.Models;
using Swashbuckle.AspNetCore.SwaggerGen;

namespace some.namespace
{
    /// <summary>
    /// https://alexdunn.org/2018/06/29/adding-a-required-http-header-to-your-swagger-ui-with-swashbuckle/.
    /// </summary>
    public class AuthenticationHeadersFilter : IOperationFilter
    {
        /// <summary>
        /// Swagger: Creates new required http header.
        /// </summary>
        /// <param name="operation"> Open Api Operation.</param>
        /// <param name="context">Operation Filter Context.</param>
        public void Apply(OpenApiOperation operation, OperationFilterContext context)
        {
            var globalAttributes = context.ApiDescription.ActionDescriptor.FilterDescriptors.Select(p => p.Filter);
            var controllerAttributes = context.MethodInfo?.DeclaringType?.GetCustomAttributes(true);
            var methodAttributes = context.MethodInfo?.GetCustomAttributes(true);
            var produceAttributes = globalAttributes
                .Union(controllerAttributes ?? throw new InvalidOperationException())
                .Union(methodAttributes)
                .OfType<SkipAuthenticationHeadersAttribute>()
                .ToList();

            if (produceAttributes.Count != 0)
            {
                return;
            }

            if (operation.Parameters == null)
            {
                operation.Parameters = new List<OpenApiParameter>();
            }

            operation.Parameters.Add(new OpenApiParameter
            {
               Name = "AccountName",
               In = ParameterLocation.Header,
               Required = true
            });

            operation.Parameters.Add(new OpenApiParameter
            {
               Name = "ApiKey",
               In = ParameterLocation.Header,
               Required = true
            });
        }
    }
}

因此，当您将属性添加到 Controller 操作时，该操作会被过滤掉。