Allow configuring default plugin that is returned from DI (weikio#40)

Author: mikkou-adafy

samples/WebApp/Controllers/CalculatorController.cs

@@ -1,4 +1,6 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json;
 using Microsoft.AspNetCore.Mvc;
 using Weikio.PluginFramework.Samples.Shared;
 using Weikio.PluginFramework.Abstractions;
@@ -11,19 +13,24 @@ public class CalculatorController : ControllerBase
  {
  private readonly IEnumerable<IOperator> _operators;
  private readonly IEnumerable<Plugin> _plugins;
+ private readonly IOperator _defaultOperator;
 
- public CalculatorController(IEnumerable<IOperator> operators, IEnumerable<Plugin> plugins, IOperator myOperator)
+ public CalculatorController(IEnumerable<IOperator> operators, IEnumerable<Plugin> plugins, IOperator defaultOperator)
  {
  _operators = operators;
  _plugins = plugins;
+ _defaultOperator = defaultOperator;
  }
 
  [HttpGet]
  public string Get()
  {
- var pluginsList = string.Join(", ", _plugins);
-
- return pluginsList;
+ return JsonSerializer.Serialize(new
+ {
+ allPlugins = _plugins.Select(p => p.ToString()),
+ operators = _operators.Select(o => o.GetType().Name),
+ defaultOperator = _defaultOperator.GetType().Name
+ }, new JsonSerializerOptions { WriteIndented = true});
  }
  }
 }

samples/WebApp/Startup.cs

@@ -6,7 +6,9 @@
 using Microsoft.Extensions.Hosting;
 using Weikio.PluginFramework.Samples.Shared;
 using Weikio.PluginFramework.Abstractions;
+using Weikio.PluginFramework.AspNetCore;
 using Weikio.PluginFramework.Catalogs;
+using Weikio.PluginFramework.Samples.SharedPlugins;
 
 namespace WebApp
 {
@@ -34,6 +36,18 @@ public void ConfigureServices(IServiceCollection services)
  // Alternatively
  // services.AddPluginFramework<IOperator>(@"..\Shared\Weikio.PluginFramework.Samples.SharedPlugins\bin\debug\netcoreapp3.1");
 
+ // Default plugin type returned can be optionally configured with DefaultType function
+ //services.AddPluginFramework()
+ // .AddPluginCatalog(folderPluginCatalog)
+ // .AddPluginType<IOperator>(configureDefault: option =>
+ // {
+ // option.DefaultType = (serviceProvider, implementingTypes) => typeof(MultiplyOperator);
+ // });
+
+ // Alternatively default plugin type can be also configured with Configure and provided with the same DefaultType function
+ //services.Configure<DefaultPluginOption>(nameof(IOperator), option =>
+ // option.DefaultType = (serviceProvider, implementingTypes) => typeof(MultiplyOperator));
+
  services.AddControllers();
  }
 

src/Weikio.PluginFramework.AspNetCore/DefaultPluginOption.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Weikio.PluginFramework.AspNetCore
+{
+ public class DefaultPluginOption
+ {
+ public Func<IServiceProvider, IEnumerable<Type>, Type> DefaultType { get; set; }
+ = (serviceProvider, implementingTypes) => implementingTypes.FirstOrDefault();
+ }
+}

src/Weikio.PluginFramework.AspNetCore/ServiceCollectionExtensions.cs

@@ -178,7 +178,8 @@ public static IServiceCollection AddPluginCatalog(this IServiceCollection servic
  return services;
  }
 
- public static IServiceCollection AddPluginType<T>(this IServiceCollection services, ServiceLifetime serviceLifetime = ServiceLifetime.Transient)
+ public static IServiceCollection AddPluginType<T>(this IServiceCollection services, ServiceLifetime serviceLifetime = ServiceLifetime.Transient,
+ Action<DefaultPluginOption> configureDefault = null)
  where T : class
  {
  var serviceDescriptorEnumerable = new ServiceDescriptor(typeof(IEnumerable<T>), sp =>
@@ -191,16 +192,43 @@ public static IServiceCollection AddPluginType<T>(this IServiceCollection servic
 
  var serviceDescriptorSingle = new ServiceDescriptor(typeof(T), sp =>
  {
+ var defaultPluginOption = GetDefaultPluginOptions<T>(configureDefault, sp);
+
  var pluginProvider = sp.GetService<PluginProvider>();
  var result = pluginProvider.GetTypes<T>();
 
- return result.FirstOrDefault();
+ var defaultType = defaultPluginOption.DefaultType(sp, result.Select(r => r.GetType()));
+
+ return result.FirstOrDefault(r => r.GetType() == defaultType);
  }, serviceLifetime);
 
  services.Add(serviceDescriptorEnumerable);
  services.Add(serviceDescriptorSingle);
 
  return services;
  }
+
+ private static DefaultPluginOption GetDefaultPluginOptions<T>(Action<DefaultPluginOption> configureDefault, IServiceProvider sp) where T : class
+ {
+ var defaultPluginOption = new DefaultPluginOption();
+
+ // If no configuration is provided though action try to get configuration from named options
+ if (configureDefault == null)
+ {
+ var optionsFromMonitor =
+ sp.GetService<IOptionsMonitor<DefaultPluginOption>>().Get(typeof(T).Name);
+
+ if (optionsFromMonitor != null)
+ {
+ defaultPluginOption = optionsFromMonitor;
+ }
+ }
+ else
+ {
+ configureDefault(defaultPluginOption);
+ }
+
+ return defaultPluginOption;
+ }
  }
 }

src/Weikio.PluginFramework.Configuration/Weikio.PluginFramework.Configuration.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
  <PropertyGroup>
  <TargetFramework>netcoreapp3.1</TargetFramework>