DRN.Framework.Utils 0.4.0-preview004

DRN.Framework.Utils package contains common codes for other DRN.Framework packages and projects developed with DRN.Framework.

Module

DRN.Utils can be added with following module

namespace DRN.Framework.Utils;

public static class UtilsModule
{
    public static IServiceCollection AddDrnUtils(this IServiceCollection collection)
    {
        collection.AddServicesWithAttributes();

        return collection;
    }
}

Dependency Injection with Attributes

Each module should be created in the assembly that will be scanned.

public static class InfraModule
{
    public static IServiceCollection AddSampleInfraServices(this IServiceCollection sc)
    {
        sc.AddServicesWithAttributes();

        return sc;
    }
}

Services resolution for attribute based services can be validated with a single line.

serviceProvider.ValidateServicesAddedByAttributes();

Attribute based dependency injection reduces wiring efforts and helps developer to focus on developing. This approach also improves service resolution validation during startup and integration testing.

    [Theory]
    [DataInlineContext]
    public void Validate_Sample_Dependencies(TestContext context)
    {
        context.ServiceCollection.AddSampleApplicationServices();
        context.ServiceCollection.AddSampleInfraServices();
        context.ValidateServices();
    }

Lifetime Attributes

Example attribute usage:

[Transient<IIndependent>]
public class Independent : IIndependent
{
}

Following attributes marks services with a lifetime and when service collection called with AddServicesWithAttributes method in the assembly marked belong they are automatically added.

namespace DRN.Framework.Utils.DependencyInjection.Attributes;

public class LifetimeAttribute<TService>(ServiceLifetime serviceLifetime, bool tryAdd = true, object? key = null)
    : LifetimeAttribute(serviceLifetime, typeof(TService), tryAdd, key);

public class LifetimeWithKeyAttribute<TService>(ServiceLifetime serviceLifetime, object key, bool tryAdd = true)
    : LifetimeAttribute(serviceLifetime, typeof(TService), tryAdd, key);

public class ScopedAttribute<TService>(bool tryAdd = true) : LifetimeAttribute<TService>(ServiceLifetime.Scoped, tryAdd);

public class ScopedWithKeyAttribute<TService>(object key, bool tryAdd = true) : LifetimeWithKeyAttribute<TService>(ServiceLifetime.Scoped, key, tryAdd);

public class TransientAttribute<TService>(bool tryAdd = true) : LifetimeAttribute<TService>(ServiceLifetime.Transient, tryAdd);

public class TransientWithKeyAttribute<TService>(object key, bool tryAdd = true) : LifetimeWithKeyAttribute<TService>(ServiceLifetime.Transient, key, tryAdd);

public class SingletonAttribute<TService>(bool tryAdd = true) : LifetimeAttribute<TService>(ServiceLifetime.Singleton, tryAdd);

public class SingletonWithKeyAttribute<TService>(object key, bool tryAdd = true) : LifetimeWithKeyAttribute<TService>(ServiceLifetime.Singleton, key, tryAdd);

HasServiceCollectionModuleAttribute

Attributes derived from HasServiceCollectionModuleAttribute can be used to mark custom service collection modules. In the following example HasDrnContextServiceCollectionModuleAttribute marks DrnContext<TContext> and its service collection module. This way dbContexts inherited from DrnContext doesn't need a lifetime attribute and they can be registered by AddServicesWithAttributes with their custom factory.

This offers following flexibility:

1. ServiceCollectionModule of DrnContexts are defined in DRN.Framework.EntityFramework
2. Inherited dbContexts are defined in user defined projects and points a module in another project.
3. AddServicesWithAttributes extension method defined in DRN.Framework.Utils registers them without depending DRN.Framework.EntityFramework project

public class HasDrnContextServiceCollectionModuleAttribute : HasServiceCollectionModuleAttribute
{
    static HasDrnContextServiceCollectionModuleAttribute() =>
        ModuleMethodInfo = typeof(ServiceCollectionExtensions)
            .GetMethod(nameof(ServiceCollectionExtensions.AddDbContextsWithConventions))!;

    public override async Task PostStartupValidationAsync(object service, IServiceProvider serviceProvider)
    {
        var appSettings = serviceProvider.GetRequiredService<IAppSettings>();
        var migrate = appSettings.Configuration.GetValue(DbContextConventions.AutoMigrateDevEnvironmentKey, false);
        if (appSettings.Environment == AppEnvironment.Development && migrate && service is DbContext context)
            await context.Database.MigrateAsync();
    }
}

[HasDrnContextServiceCollectionModule]
public abstract class DrnContext<TContext> : DbContext, IDesignTimeDbContextFactory<TContext>, IDesignTimeServices where TContext : DbContext, new()
{
...

HasServiceCollectionModuleAttribute's PostStartupValidationAsync will be called when,

• ValidateServicesAddedByAttributes extension method called from service provider if all services resolved successfully.
• For instance, DrnContext can apply EF migrations after service provider services resolved successfully.

Configurations

Following configuration sources can be used to add configurations from different sources

• JsonSerializerConfigurationSource converts poco objects to configuration
• RemoteJsonConfigurationSource fetches remote configuration (experimental and incomplete)

Following MountedSettingsConventions will be added to configuration.

• /appconfig/json-settings json files will be added to configuration if any exist
• /appconfig/key-per-file-settings files will be added to configuration if any exist
• IMountedSettingsConventionsOverride overrides default /appconfig location if added to service collection before host built

namespace DRN.Framework.Utils.Settings.Conventions;

public static class MountedSettingsConventions
{
    public const string DefaultMountDirectory = "/appconfig";
    
    public static string JsonSettingsMountDirectory(string? mountDirectory = null)
        => Path.Combine(mountDirectory ?? DefaultMountDirectory, "json-settings");
    public static string KeyPerFileSettingsMountDirectory(string? mountDirectory = null)
        => Path.Combine(mountDirectory ?? DefaultMountDirectory, "key-per-file-settings");

    public static DirectoryInfo JsonSettingDirectoryInfo(string? mountDirectory = null)
        => new(JsonSettingsMountDirectory(mountDirectory));
}

public interface IMountedSettingsConventionsOverride
{
    string? MountedSettingsDirectory { get; }
}

AppSettings

Following IAppSettings interface is defined and can be used to obtain appsettings. It has utility methods that allow fail fast.

namespace DRN.Framework.Utils.Settings;

public interface IAppSettings
{
    AppEnvironment Environment { get; }
    IConfiguration Configuration { get; }
    bool TryGetConnectionString(string name, out string connectionString);
    string GetRequiredConnectionString(string name);
    bool TryGetSection(string key, out IConfigurationSection section);
    IConfigurationSection GetRequiredSection(string key);
    T? GetValue<T>(string key);
    T? GetValue<T>(string key, T defaultValue);
    T? Get<T>(string key, Action<BinderOptions>? configureOptions = null);
    ConfigurationDebugView GetDebugView();
}

ExtensionMethods

• ServiceCollectionExtensions
  • ReplaceInstance
  • ReplaceTransient
  • ReplaceScoped
  • ReplaceSingleton
  • GetAllAssignableTo<TService>
• StringExtensions
  • ToStream
• TypeExtensions
  • MakeGenericMethod
• AssemblyExtensions
  • GetTypesAssignableTo

Semper Progredi: Always Progressive

Commit Info

Author: Duran Serkan KILIÇ
Date: 2024-05-12 19:12:08 +0300
Hash: 993cdbb7e555a472b963363737f38148170d84c5