添加Api跨域配置信息的JSON配置节点支持

[gmf520]

您的功能请求与现有问题有关吗？请描述

现在跨域配置需要自己写代码实现，可以通过读取JSON配置信息来进行配置

[wgs004]

您好，现在跨域策略的增加是通过继承MvcPack类，重写AddCors方法来实现，但是FunctionAuthorizationPackBase类又DependsOnPacks于MvcFunctionPack，而MvcFunctionPack依赖于MvcPack，导致冲突：如果自己继承MvcPack会导致底层初始化pack时将MvcPack替换掉，导致系统异常找不到MvcPack，请问目前有解决的方法吗？

[gmf520]

添加新接口 ICorsInitializer 用于将Cors的初始化业务从MvcPack中剥离出来，防止自定义Cors时需要重写MvcPack导致 @wgs004 提到的冲突情况出现

ICorsInitializer

namespace OSharp.AspNetCore.Cors
{
    /// <summary>
    /// 定义Cors初始化器
    /// </summary>
    public interface ICorsInitializer
    {
        /// <summary>
        /// 添加Cors
        /// </summary>
        IServiceCollection AddCors(IServiceCollection services);

        /// <summary>
        /// 应用Cors
        /// </summary>
        IApplicationBuilder UseCors(IApplicationBuilder app);
    }
}

DefaultCorsInitializer

实现了一个常规的Cors初始化器

namespace OSharp.AspNetCore.Cors
{
    /// <summary>
    /// 默认Cors初始化器
    /// </summary>
    public class DefaultCorsInitializer : ICorsInitializer
    {
        private CorsOptions _cors;

        /// <summary>
        /// 添加Cors
        /// </summary>
        public virtual IServiceCollection AddCors(IServiceCollection services)
        {
            IConfiguration configuration = services.GetConfiguration();
            CorsOptions cors = new CorsOptions();
            configuration.Bind("OSharp:Cors", cors);
            _cors = cors;
            if (!cors.Enabled)
            {
                return services;
            }

            if (string.IsNullOrEmpty(cors.PolicyName))
            {
                throw new OsharpException("配置文件中OSharp:Cors节点的PolicyName不能为空");
            }

            services.AddCors(opts => opts.AddPolicy(cors.PolicyName,
                policy =>
                {
                    if (cors.AllowAnyHeader)
                        policy.AllowAnyHeader();
                    else if (cors.WithHeaders != null)
                        policy.WithHeaders(cors.WithHeaders);

                    if (cors.AllowAnyMethod)
                        policy.AllowAnyMethod();
                    else if (cors.WithMethods != null)
                        policy.WithMethods(cors.WithMethods);

                    if (cors.AllowCredentials) policy.AllowCredentials();
                    else if (cors.DisallowCredentials) policy.DisallowCredentials();

                    if (cors.AllowAnyOrigin) policy.AllowAnyOrigin();
                    else if (cors.WithOrigins != null) policy.WithOrigins(cors.WithOrigins);
                }));

            return services;
        }

        /// <summary>
        /// 应用Cors
        /// </summary>
        public virtual IApplicationBuilder UseCors(IApplicationBuilder app)
        {
            if (_cors.Enabled)
            {
                app.UseCors(_cors.PolicyName);
            }

            return app;
        }
    }
}

CorsOptions

相应的配置选项类

namespace OSharp.Core.Options
{
    /// <summary>
    /// Cors选项
    /// </summary>
    public class CorsOptions
    {
        /// <summary>
        /// 获取或设置 策略名称
        /// </summary>
        public string PolicyName { get; set; }

        /// <summary>
        /// 获取或设置 允许任意请求头
        /// </summary>
        public bool AllowAnyHeader { get; set; }

        /// <summary>
        /// 获取或设置 允许的请求头
        /// </summary>
        public string[] WithHeaders { get; set; }

        /// <summary>
        /// 获取或设置 允许任意方法
        /// </summary>
        public bool AllowAnyMethod { get; set; }

        /// <summary>
        /// 获取或设置 允许的方法
        /// </summary>
        public string[] WithMethods { get; set; }

        /// <summary>
        /// 获取或设置 允许跨域凭据
        /// </summary>
        public bool AllowCredentials { get; set; }

        /// <summary>
        /// 获取或设置 禁止跨域凭据
        /// </summary>
        public bool DisallowCredentials { get; set; }

        /// <summary>
        /// 获取或设置 允许任意来源
        /// </summary>
        public bool AllowAnyOrigin { get; set; }

        /// <summary>
        /// 获取或设置 允许的来源
        /// </summary>
        public string[] WithOrigins { get; set; }

        /// <summary>
        /// 获取或设置 是否启用
        /// </summary>
        public bool Enabled { get; set; }
    }
}

配置选项类型CorsOptions对应的JSON配置节点，位于 OSharp:Cors，示例如下：

    "Cors": {
      "PolicyName": "MyCors",
      "AllowAnyHeader": true,
      "WithMethods": [ "POST", "PUT", "DELETE" ],
      "WithOrigins": [ "http://example.com" ],
      "Enabled": true 
    }

如果要自定义ICorsInitializer实现，需要在AddOSharp之前添加

services.AddSingleton<ICorsInitializer>(new MyCorsInitializer());