4. abp中的asp.net core模塊剖析

相關模塊

1. AbpAspNetCoreModule
2. AbpAspNetCoreMvcModule
3. AbpAspNetCoreMvcContractsModule

abp通過這三個模塊載入並配置了 asp.net core。，最主要的就是AbpAspNetCoreMvcModule模塊類，abp如何基於aspnet core構建自己的控制器和AppServices，就是在這個類中。

• AbpAspNetCoreMvcModule
  將AbpAspNetCoreMvcConventionalRegister類添加到ConventionalRegistrarList列表中，該類主要是用來註入依賴及獲取服務生命周期的。

    public override void PreConfigureServices(ServiceConfigurationContext context)
    {
        context.Services.AddConventionalRegistrar(new AbpAspNetCoreMvcConventionalRegistrar());
    }

  接下來就是重點，在ConfigureServices方法中配置視圖和控制器，當然是基於 asp.net core mvc。首先配置Razor：

    context.Services.Insert(0,
        ServiceDescriptor.Singleton<IConfigureOptions<RazorViewEngineOptions>>(
            new ConfigureOptions<RazorViewEngineOptions>(options =>
                {
                    options.FileProviders.Add(
                        new RazorViewEngineVirtualFileProvider(
                            context.Services.GetSingletonInstance<IObjectAccessor<IServiceProvider>>()
                        )
                    );
                }
            )
        )
    );
  

  配置Api描述符：

    Configure<ApiDescriptionModelOptions>(options =>
    {
        options.IgnoredInterfaces.AddIfNotContains(typeof(IAsyncActionFilter));
        options.IgnoredInterfaces.AddIfNotContains(typeof(IFilterMetadata));
        options.IgnoredInterfaces.AddIfNotContains(typeof(IActionFilter));
    });

  可以看到 aspnetcore mvc中的過濾器介面，我們將其添加到了Api描述模型選項類中。下麵就是註入MVC：

    var mvcCoreBuilder = context.Services.AddMvcCore();
    var mvcBuilder = context.Services.AddMvc()
        .AddDataAnnotationsLocalization(options =>
        {
            options.DataAnnotationLocalizerProvider = (type, factory) =>
            {
                var resourceType = abpMvcDataAnnotationsLocalizationOptions.AssemblyResources.GetOrDefault(type.Assembly);
                return factory.Create(resourceType ?? type);
            };
        })
        .AddViewLocalization();

  使用DI創建控制器，使用的是aspnet core預設的控制器激活器ServiceBasedControllerActivator類：

    //Use DI to create controllers
    context.Services.Replace(ServiceDescriptor.Transient<IControllerActivator, ServiceBasedControllerActivator>());

  abp提供了一個基於約定的控制器特性提供器類，這個類是基於 aspnetcore mvc的ControllerFeatureProvider構建自己的控制器，並檢索判斷控制器。

    //Add feature providers
    var partManager = context.Services.GetSingletonInstance<ApplicationPartManager>();
    var application = context.Services.GetSingletonInstance<IAbpApplication>();
  
    partManager.FeatureProviders.Add(new AbpConventionalControllerFeatureProvider(application));

  該類源碼：

    public class AbpConventionalControllerFeatureProvider : ControllerFeatureProvider
    {
        private readonly IAbpApplication _application;
  
        public AbpConventionalControllerFeatureProvider(IAbpApplication application)
        {
            _application = application;
        }
  
        protected override bool IsController(TypeInfo typeInfo)
        {
            //TODO: Move this to a lazy loaded field for efficiency.
            if (_application.ServiceProvider == null)
            {
                return false;
            }
  
            var configuration = _application.ServiceProvider
                .GetRequiredService<IOptions<AbpAspNetCoreMvcOptions>>().Value
                .ConventionalControllers
                .ConventionalControllerSettings
                .GetSettingOrNull(typeInfo.AsType());
  
            return configuration != null;
        }
    }

  由上，abp會基於aspnetcore mvc配置abp的mvc模塊，特別是Controller的創建。從代碼裡面可以看出獲取到AbpAspNetCoreMvcOptions的服務再去檢索規約的控制器。由此返回是否是控制器。AbpAspNetCoreMvcOptions類是Abp對aspnet core mvc的一個封裝，源碼如下：

    public class AbpAspNetCoreMvcOptions
    {
        public ConventionalControllerOptions ConventionalControllers { get; }
  
        public AbpAspNetCoreMvcOptions()
        {
            ConventionalControllers = new ConventionalControllerOptions();
        }
    }
  
    //規約控制器集合
    public class ConventionalControllerOptions
    {
        public ConventionalControllerSettingList ConventionalControllerSettings { get; }
  
        public List<Type> FormBodyBindingIgnoredTypes { get; }
  
        public ConventionalControllerOptions()
        {
            ConventionalControllerSettings = new ConventionalControllerSettingList();
  
            FormBodyBindingIgnoredTypes = new List<Type>
            {
                typeof(IFormFile)
            };
        }
  
        public ConventionalControllerOptions Create(Assembly assembly, [CanBeNull] Action<ConventionalControllerSetting> optionsAction = null)
        {
            var setting = new ConventionalControllerSetting(assembly, ModuleApiDescriptionModel.DefaultRootPath); // DefaultRootPath = app，abp路由就是以這個app開頭的。
            optionsAction?.Invoke(setting);
            setting.Initialize();
            ConventionalControllerSettings.Add(setting);
            return this;
        }
    }

  AbpAspNetCoreMvcOptions實際上是通過ConventionalControllerOptions來完成規約的配置，來實現自定義的路由以及動態API。

• AspNetCoreDescriptionModelProvider

  abp是如何aspnet core創建自己的API的呢？有這麼一個類AspNetCoreDescriptionModelProvider，這個類就是提供了aspnet core的描述模型，源碼如下：

    public class AspNetCoreApiDescriptionModelProvider : IApiDescriptionModelProvider, ITransientDependency
    {
        public ILogger<AspNetCoreApiDescriptionModelProvider> Logger { get; set; }
  
        private readonly IApiDescriptionGroupCollectionProvider _descriptionProvider;
        private readonly AbpAspNetCoreMvcOptions _options;
        private readonly ApiDescriptionModelOptions _modelOptions;
  
        public AspNetCoreApiDescriptionModelProvider(
            IApiDescriptionGroupCollectionProvider descriptionProvider,
            IOptions<AbpAspNetCoreMvcOptions> options,
            IOptions<ApiDescriptionModelOptions> modelOptions)
        {
            _descriptionProvider = descriptionProvider;
            _options = options.Value;
            _modelOptions = modelOptions.Value;
  
            Logger = NullLogger<AspNetCoreApiDescriptionModelProvider>.Instance;
        }
  
        public ApplicationApiDescriptionModel CreateApiModel()
        {
            //TODO: Can cache the model?
  
            var model = ApplicationApiDescriptionModel.Create();
  
            foreach (var descriptionGroupItem in _descriptionProvider.ApiDescriptionGroups.Items)
            {
                foreach (var apiDescription in descriptionGroupItem.Items)
                {
                    if (!apiDescription.ActionDescriptor.IsControllerAction())
                    {
                        continue;
                    }
  
                    AddApiDescriptionToModel(apiDescription, model);
                }
            }
  
            return model;
        }
  
        private void AddApiDescriptionToModel(ApiDescription apiDescription, ApplicationApiDescriptionModel model)
        {
            var controllerType = apiDescription.ActionDescriptor.AsControllerActionDescriptor().ControllerTypeInfo.AsType();
            var setting = FindSetting(controllerType);
  
            var moduleModel = model.GetOrAddModule(GetRootPath(controllerType, setting));
  
            var controllerModel = moduleModel.GetOrAddController(controllerType.FullName, CalculateControllerName(controllerType, setting), controllerType, _modelOptions.IgnoredInterfaces);
  
            var method = apiDescription.ActionDescriptor.GetMethodInfo();
  
            var uniqueMethodName = GetUniqueActionName(method);
            if (controllerModel.Actions.ContainsKey(uniqueMethodName))
            {
                Logger.LogWarning($"Controller '{controllerModel.ControllerName}' contains more than one action with name '{uniqueMethodName}' for module '{moduleModel.RootPath}'. Ignored: " + method);
                return;
            }
  
            Logger.LogDebug($"ActionApiDescriptionModel.Create: {controllerModel.ControllerName}.{uniqueMethodName}");
            var actionModel = controllerModel.AddAction(uniqueMethodName, ActionApiDescriptionModel.Create(
                uniqueMethodName,
                method,
                apiDescription.RelativePath,
                apiDescription.HttpMethod,
                GetSupportedVersions(controllerType, method, setting)
            ));
  
            AddParameterDescriptionsToModel(actionModel, method, apiDescription);
        }
  
        private static string CalculateControllerName(Type controllerType, ConventionalControllerSetting setting)
        {
            var controllerName = controllerType.Name.RemovePostFix("Controller").RemovePostFix(ApplicationService.CommonPostfixes);
  
            if (setting?.UrlControllerNameNormalizer != null)
            {
                controllerName = setting.UrlControllerNameNormalizer(new UrlControllerNameNormalizerContext(setting.RootPath, controllerName));
            }
  
            return controllerName;
        }
    }

  這個類為我們提供了從Action到Controller的描述，構建了abp自己的api。它的調用有兩個地方，一個是AbpApiDefinitionController，一個是ProxyScriptManager，前者是定義Abp的api控制器定義的地方，後者則是生成代理腳本的地方，abp的示例項目BookStore中會調用介面Abp/ServiceProxyScript生成一個js文件，這個js文件裡面就是api的url地址，前端通過訪問這個api地址來訪問appservice等後端方法。源碼如下：

    [Area("Abp")]
    [Route("Abp/ServiceProxyScript")]
    [DisableAuditing]
    public class AbpServiceProxyScriptController : AbpController
    {
        private readonly IProxyScriptManager _proxyScriptManager;
  
        public AbpServiceProxyScriptController(IProxyScriptManager proxyScriptManager)
        {
            _proxyScriptManager = proxyScriptManager;
        }
  
        [HttpGet]
        [Produces("text/javascript", "text/plain")]
        public string GetAll(ServiceProxyGenerationModel model)
        {
            model.Normalize();
            return _proxyScriptManager.GetScript(model.CreateOptions());
        }
    }

• AbpHttpModule模塊
  Abp創建jquery代理腳本生成器，主要用來生產api提供給前端訪問

    public override void ConfigureServices(ServiceConfigurationContext context)
    {
        Configure<AbpApiProxyScriptingOptions>(options =>
        {
            options.Generators[JQueryProxyScriptGenerator.Name] = typeof(JQueryProxyScriptGenerator);
        });
    }