设置模块Volo.Abp.Settings

一、AbpSettingsModule的模块的生命周期的定义

SettingOptions提供ISettingDefinitionProvider，Define(ISettingDefinitionContext context)

在模块的PreConfigureServices，只需要实现了ISettingDefinitionProvider，自动添加到设置的定义里。比如邮件设置，由SettingDefinitionManager下CreateSettingDefinitions遍历得到SettingDefinitionContext

ISettingValueProvider 提供了4个自定义的设置值的提供者，分别是默认值提供者，全局值提供者，租户值提供，用户值提供

 public override void PreConfigureServices(ServiceConfigurationContext context)
        {
            AutoAddDefinitionProviders(context.Services);
        }

        public override void ConfigureServices(ServiceConfigurationContext context)
        {
            Configure<SettingOptions>(options =>
            {
                options.ValueProviders.Add<DefaultValueSettingValueProvider>();
                options.ValueProviders.Add<GlobalSettingValueProvider>();
                options.ValueProviders.Add<TenantSettingValueProvider>();
                options.ValueProviders.Add<UserSettingValueProvider>();
            });
        }

        private static void AutoAddDefinitionProviders(IServiceCollection services)
        {
            var definitionProviders = new List<Type>();

            services.OnRegistred(context =>
            {
                if (typeof(ISettingDefinitionProvider).IsAssignableFrom(context.ImplementationType))
                {
                    definitionProviders.Add(context.ImplementationType);
                }
            });

            services.Configure<SettingOptions>(options =>
            {
                options.DefinitionProviders.AddIfNotContains(definitionProviders);
            });
        }

二、SettingProvider是主要入口，构造函数有options，serviceProvider，settingDefinitionManager，settingEncryptionService

       主要为了得到属性值

       public virtual async Task<string> GetOrNullAsync(string name)
        {
           //获取属性值
            var setting = SettingDefinitionManager.Get(name);
            var providers = Enumerable
                .Reverse(Providers.Value);

            if (setting.Providers.Any())
            {
                providers = providers.Where(p => setting.Providers.Contains(p.Name));
            }

            //TODO: How to implement setting.IsInherited?

            var value = await GetOrNullValueFromProvidersAsync(providers, setting);
            //加密
            if (setting.IsEncrypted)
            {
                value = SettingEncryptionService.Decrypt(setting, value);
            }
            return value;
        }

　　

  protected virtual async Task<string> GetOrNullValueFromProvidersAsync(
            IEnumerable<ISettingValueProvider> providers,
            SettingDefinition setting)
        {
         //遍历对应值提供Providers，获取对应的值
            foreach (var provider in providers)
            {
                var value = await provider.GetOrNullAsync(setting);
                if (value != null)
                {
                    return value;
                }
            }

            return null;
        }

　　

领域建模知识

1、首先确定settingdefinition配置定义,如名字，显示名字，描述，默认值，是否对客户端可显示，提供列表，用户自定义属性，是否加密

2、settingdefinitionContext上下文，提供配置的定义SettingDefinition ，存储配置字典的定义    Dictionary<string, SettingDefinition> 

3、SettingDefinitionProvider提供者，定义 配置的上下文Define(ISettingDefinitionContext context)

比如邮件设置的上下文  

 internal class EmailSettingProvider : SettingDefinitionProvider
    {
        public override void Define(ISettingDefinitionContext context)
        {
            context.Add(
                new SettingDefinition(EmailSettingNames.Smtp.Host, "127.0.0.1"),
                new SettingDefinition(EmailSettingNames.Smtp.Port, "25"),
                new SettingDefinition(EmailSettingNames.Smtp.UserName),
                new SettingDefinition(EmailSettingNames.Smtp.Password, isEncrypted: true),
                new SettingDefinition(EmailSettingNames.Smtp.Domain),
                new SettingDefinition(EmailSettingNames.Smtp.EnableSsl, "false"),
                new SettingDefinition(EmailSettingNames.Smtp.UseDefaultCredentials, "true"),
                new SettingDefinition(EmailSettingNames.DefaultFromAddress, "[email protected]"),
                new SettingDefinition(EmailSettingNames.DefaultFromDisplayName, "ABP application")
            );
        }
    }

 4、配置值的提供者ISettingValueProvider，有多个提供者，比如

     1）默认提供者，获取配置定义的值

     2）全局提供者，从ISettingStore获取值，ProviderName = "Global"

     3）租户提供者，从ISettingStore获取值，providerName=Tenant，providerKey=CurrentTenant.Id?.ToString()

     4）用户提供者，从ISettingStore获取值，providerName=User，providerKey=CurrentUser.Id.ToString()

5、settingdefinitionManager的管理，获取到配置的定义，所有设置的定义   1)初始化所有DefinitionProviders，配置settingdefinitionContext上下文

    

 public SettingDefinitionManager(
            IOptions<SettingOptions> options,
            IServiceProvider serviceProvider)
        {
            ServiceProvider = serviceProvider;
            Options = options.Value;

            SettingDefinitions = new Lazy<IDictionary<string, SettingDefinition>>(CreateSettingDefinitions, true);
        }

 protected virtual IDictionary<string, SettingDefinition> CreateSettingDefinitions()
        {
            var settings = new Dictionary<string, SettingDefinition>();

            using (var scope = ServiceProvider.CreateScope())
            {
                var providers = Options
                    .DefinitionProviders
                    .Select(p => scope.ServiceProvider.GetRequiredService(p) as ISettingDefinitionProvider)
                    .ToList();

                foreach (var provider in providers)
                {
                    provider.Define(new SettingDefinitionContext(settings));
                }
            }

            return settings;
        }