Add callback method for when a module class has been added (#934)

commit 5b047bf02b
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Fri Feb 2 22:22:00 2018 +0100

    [feature/OnModuleAdded] Quickstart fixes (#946)

    * Quickstart: fix minor derp

    * Other overdue fixes

commit bd3e9eee94
Author: Christopher F <computerizedtaco@gmail.com>
Date:   Sat Jan 27 16:51:18 2018 -0500

    Resort usings in ModuleBase

commit 8042767579
Author: Christopher F <computerizedtaco@gmail.com>
Date:   Sat Jan 27 16:41:39 2018 -0500

    Clean up removed owned IServiceProvider

commit 30066cb102
Author: Christopher F <computerizedtaco@gmail.com>
Date:   Sat Jan 27 16:37:22 2018 -0500

    Remove redundant try-catch around OnModuleBuilding invocation

    If this exception is going to be rethrown, there's no reason to include
    a try-catch.

commit 60c7c31d44
Author: Christopher F <computerizedtaco@gmail.com>
Date:   Sat Jan 27 16:36:27 2018 -0500

    Include the ModuleBuilder in OnModuleBuilding

    This allows modules hooking into OnModuleBuilding method to mutate
    theirselves at runtime.

commit b6a9ff5786
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Mon Jan 22 13:17:14 2018 +0100

    #DERP

commit f623d19c68
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Mon Jan 22 13:15:31 2018 +0100

    Resolution for #937 because it's literally 4 lines of code

commit 8272c9675b
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Mon Jan 22 11:39:28 2018 +0100

    Re-adjust quickstart

commit e30b907135
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Mon Jan 22 11:35:08 2018 +0100

    Undo experimental changes, request IServiceProvider instance everywhere instead

commit ad7e0a46c8
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Fri Jan 19 03:40:27 2018 +0100

    Fix quickstart leftover from previous draft

commit e3349ef3d4
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Fri Jan 19 03:33:46 2018 +0100

    Doc comment on items

commit 81bd9111fa
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Fri Jan 19 03:16:44 2018 +0100

    Add comment about the ServiceProviderFactory in the quickstart

commit 72b5e6c8a1
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Fri Jan 19 03:10:40 2018 +0100

    Remove superfluous comments, provide simpler alternative for setting the ServiceProvider.

commit 74b17b0e04
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Tue Jan 16 18:06:28 2018 +0100

    Experimental change for feedback

commit 7b100e99bb
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Mon Jan 15 23:34:06 2018 +0100

    * Make the service provider parameters required

    * Adjust quickstart guide to reflect changes

commit 7f1b792946
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Mon Jan 15 20:04:37 2018 +0100

    I..... missed one.

commit 031b289d80
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Mon Jan 15 20:02:20 2018 +0100

    Rename method to more intuitive 'OnModuleBuilding'

commit 9a166ef1d0
Author: Joe4evr <jii.geugten@gmail.com>
Date:   Mon Jan 15 19:09:10 2018 +0100

    Add callback method for when a module class has been added to the CommandService.

docs/guides/getting_started/samples/intro/structure.cs

@@ -19,10 +19,10 @@ class Program
 
     private readonly DiscordSocketClient _client;
     
-    // Keep the CommandService and IServiceCollection around for use with commands.
+    // Keep the CommandService and DI container around for use with commands.
     // These two types require you install the Discord.Net.Commands package.
-    private readonly IServiceCollection _map = new ServiceCollection();
-    private readonly CommandService _commands = new CommandService();
+    private readonly CommandService _commands;
+    private readonly IServiceProvider _services;
 
     private Program()
     {
@@ -41,14 +41,45 @@ class Program
             // add the `using` at the top, and uncomment this line:
             //WebSocketProvider = WS4NetProvider.Instance
         });
+        
+        _commands = new CommandService(new CommandServiceConfig
+        {
+            // Again, log level:
+            LogLevel = LogSeverity.Info,
+            
+            // There's a few more properties you can set,
+            // for example, case-insensitive commands.
+            CaseSensitiveCommands = false,
+        });
+        
         // Subscribe the logging handler to both the client and the CommandService.
-        _client.Log += Logger;
-        _commands.Log += Logger;
+        _client.Log += Log;
+        _commands.Log += Log;
+        
+        // Setup your DI container.
+        _services = ConfigureServices(),
+        
+    }
+    
+    // If any services require the client, or the CommandService, or something else you keep on hand,
+    // pass them as parameters into this method as needed.
+    // If this method is getting pretty long, you can seperate it out into another file using partials.
+    private static IServiceProvider ConfigureServices()
+    {
+        var map = new ServiceCollection()        
+            // Repeat this for all the service classes
+            // and other dependencies that your commands might need.
+            .AddSingleton(new SomeServiceClass());
+            
+        // When all your required services are in the collection, build the container.
+        // Tip: There's an overload taking in a 'validateScopes' bool to make sure
+        // you haven't made any mistakes in your dependency graph.
+        return map.BuildServiceProvider();
     }
 
     // Example of a logging handler. This can be re-used by addons
     // that ask for a Func<LogMessage, Task>.
-    private static Task Logger(LogMessage message)
+    private static Task Log(LogMessage message)
     {
         switch (message.Severity)
         {
@@ -92,24 +123,15 @@ class Program
         await Task.Delay(Timeout.Infinite);
     }
 
-    private IServiceProvider _services;
-    
     private async Task InitCommands()
     {
-        // Repeat this for all the service classes
-        // and other dependencies that your commands might need.
-        _map.AddSingleton(new SomeServiceClass());
-
-        // When all your required services are in the collection, build the container.
-        // Tip: There's an overload taking in a 'validateScopes' bool to make sure
-        // you haven't made any mistakes in your dependency graph.
-        _services = _map.BuildServiceProvider();
-
         // Either search the program and add all Module classes that can be found.
         // Module classes MUST be marked 'public' or they will be ignored.
-        await _commands.AddModulesAsync(Assembly.GetEntryAssembly());
+        // You also need to pass your 'IServiceProvider' instance now,
+        // so make sure that's done before you get here.
+        await _commands.AddModulesAsync(Assembly.GetEntryAssembly(), _services);
         // Or add Modules manually if you prefer to be a little more explicit:
-        await _commands.AddModuleAsync<SomeModule>();
+        await _commands.AddModuleAsync<SomeModule>(_services);
         // Note that the first one is 'Modules' (plural) and the second is 'Module' (singular).
 
         // Subscribe a handler to see if a message invokes a command.
@@ -123,8 +145,6 @@ class Program
         if (msg == null) return;
 
         // We don't want the bot to respond to itself or other bots.
-        // NOTE: Selfbots should invert this first check and remove the second
-        // as they should ONLY be allowed to respond to messages from the same account.
         if (msg.Author.Id == _client.CurrentUser.Id || msg.Author.IsBot) return;
         
         // Create a number to track where the prefix ends and the command begins
@@ -140,10 +160,12 @@ class Program
             
             // Execute the command. (result does not indicate a return value, 
             // rather an object stating if the command executed successfully).
-            var result = await _commands.ExecuteAsync(context, pos, _services);
+            var result = await _commands.ExecuteAsync(context, pos);
 
             // Uncomment the following lines if you want the bot
-            // to send a message if it failed (not advised for most situations).
+            // to send a message if it failed.
+            // This does not catch errors from commands with 'RunMode.Async',
+            // subscribe a handler for '_commands.CommandExecuted' to see those.
             //if (!result.IsSuccess && result.Error != CommandError.UnknownCommand)
             //    await msg.Channel.SendMessageAsync(result.ErrorReason);
         }

src/Discord.Net.Commands/Builders/ModuleBuilder.cs

@@ -1,5 +1,6 @@
-using System;
+using System;
 using System.Collections.Generic;
+using System.Reflection;
 using System.Threading.Tasks;
 using Microsoft.Extensions.DependencyInjection;
 
@@ -18,6 +19,7 @@ namespace Discord.Commands.Builders
         public string Name { get; set; }
         public string Summary { get; set; }
         public string Remarks { get; set; }
+        public string Group { get; set; }
 
         public IReadOnlyList<CommandBuilder> Commands => _commands;
         public IReadOnlyList<ModuleBuilder> Modules => _submodules;
@@ -25,6 +27,8 @@ namespace Discord.Commands.Builders
         public IReadOnlyList<Attribute> Attributes => _attributes;
         public IReadOnlyList<string> Aliases => _aliases;
 
+        internal TypeInfo TypeInfo { get; set; }
+
         //Automatic
         internal ModuleBuilder(CommandService service, ModuleBuilder parent)
         {
@@ -111,17 +115,23 @@ namespace Discord.Commands.Builders
             return this;
         }
 
-        private ModuleInfo BuildImpl(CommandService service, ModuleInfo parent = null)
+        private ModuleInfo BuildImpl(CommandService service, IServiceProvider services, ModuleInfo parent = null)
         {
             //Default name to first alias
             if (Name == null)
                 Name = _aliases[0];
 
-            return new ModuleInfo(this, service, parent);
+            if (TypeInfo != null)
+            {
+                var moduleInstance = ReflectionUtils.CreateObject<IModuleBase>(TypeInfo, service, services);
+                moduleInstance.OnModuleBuilding(service, this);
+            }
+
+            return new ModuleInfo(this, service, services, parent);
         }
 
-        public ModuleInfo Build(CommandService service) => BuildImpl(service);
+        public ModuleInfo Build(CommandService service, IServiceProvider services) => BuildImpl(service, services);
 
-        internal ModuleInfo Build(CommandService service, ModuleInfo parent) => BuildImpl(service, parent);
+        internal ModuleInfo Build(CommandService service, IServiceProvider services, ModuleInfo parent) => BuildImpl(service, services, parent);
     }
 }

src/Discord.Net.Commands/Builders/ModuleClassBuilder.cs

@@ -42,8 +42,8 @@ namespace Discord.Commands
         }
 
 
-        public static Task<Dictionary<Type, ModuleInfo>> BuildAsync(CommandService service, params TypeInfo[] validTypes) => BuildAsync(validTypes, service);
-        public static async Task<Dictionary<Type, ModuleInfo>> BuildAsync(IEnumerable<TypeInfo> validTypes, CommandService service)
+        public static Task<Dictionary<Type, ModuleInfo>> BuildAsync(CommandService service, IServiceProvider services, params TypeInfo[] validTypes) => BuildAsync(validTypes, service, services);
+        public static async Task<Dictionary<Type, ModuleInfo>> BuildAsync(IEnumerable<TypeInfo> validTypes, CommandService service, IServiceProvider services)
         {
             /*if (!validTypes.Any())
                 throw new InvalidOperationException("Could not find any valid modules from the given selection");*/
@@ -63,11 +63,11 @@ namespace Discord.Commands
 
                 var module = new ModuleBuilder(service, null);
 
-                BuildModule(module, typeInfo, service);
-                BuildSubTypes(module, typeInfo.DeclaredNestedTypes, builtTypes, service);
+                BuildModule(module, typeInfo, service, services);
+                BuildSubTypes(module, typeInfo.DeclaredNestedTypes, builtTypes, service, services);
                 builtTypes.Add(typeInfo);
 
-                result[typeInfo.AsType()] = module.Build(service);
+                result[typeInfo.AsType()] = module.Build(service, services);
             }
 
             await service._cmdLogger.DebugAsync($"Successfully built {builtTypes.Count} modules.").ConfigureAwait(false);
@@ -75,7 +75,7 @@ namespace Discord.Commands
             return result;
         }
 
-        private static void BuildSubTypes(ModuleBuilder builder, IEnumerable<TypeInfo> subTypes, List<TypeInfo> builtTypes, CommandService service)
+        private static void BuildSubTypes(ModuleBuilder builder, IEnumerable<TypeInfo> subTypes, List<TypeInfo> builtTypes, CommandService service, IServiceProvider services)
         {
             foreach (var typeInfo in subTypes)
             {
@@ -87,17 +87,18 @@ namespace Discord.Commands
                 
                 builder.AddModule((module) => 
                 {
-                    BuildModule(module, typeInfo, service);
-                    BuildSubTypes(module, typeInfo.DeclaredNestedTypes, builtTypes, service);
+                    BuildModule(module, typeInfo, service, services);
+                    BuildSubTypes(module, typeInfo.DeclaredNestedTypes, builtTypes, service, services);
                 });
 
                 builtTypes.Add(typeInfo);
             }
         }
 
-        private static void BuildModule(ModuleBuilder builder, TypeInfo typeInfo, CommandService service)
+        private static void BuildModule(ModuleBuilder builder, TypeInfo typeInfo, CommandService service, IServiceProvider services)
         {
             var attributes = typeInfo.GetCustomAttributes();
+            builder.TypeInfo = typeInfo;
 
             foreach (var attribute in attributes)
             {
@@ -117,6 +118,7 @@ namespace Discord.Commands
                         break;
                     case GroupAttribute group:
                         builder.Name = builder.Name ?? group.Prefix;
+                        builder.Group = group.Prefix;
                         builder.AddAliases(group.Prefix);
                         break;
                     case PreconditionAttribute precondition:
@@ -140,12 +142,12 @@ namespace Discord.Commands
             {
                 builder.AddCommand((command) => 
                 {
-                    BuildCommand(command, typeInfo, method, service);
+                    BuildCommand(command, typeInfo, method, service, services);
                 });
             }
         }
 
-        private static void BuildCommand(CommandBuilder builder, TypeInfo typeInfo, MethodInfo method, CommandService service)
+        private static void BuildCommand(CommandBuilder builder, TypeInfo typeInfo, MethodInfo method, CommandService service, IServiceProvider serviceprovider)
         {
             var attributes = method.GetCustomAttributes();
             
@@ -191,7 +193,7 @@ namespace Discord.Commands
             {
                 builder.AddParameter((parameter) => 
                 {
-                    BuildParameter(parameter, paramInfo, pos++, count, service);
+                    BuildParameter(parameter, paramInfo, pos++, count, service, serviceprovider);
                 });
             }
 
@@ -227,7 +229,7 @@ namespace Discord.Commands
             builder.Callback = ExecuteCallback;
         }
 
-        private static void BuildParameter(ParameterBuilder builder, System.Reflection.ParameterInfo paramInfo, int position, int count, CommandService service)
+        private static void BuildParameter(ParameterBuilder builder, System.Reflection.ParameterInfo paramInfo, int position, int count, CommandService service, IServiceProvider services)
         {
             var attributes = paramInfo.GetCustomAttributes();
             var paramType = paramInfo.ParameterType;
@@ -245,7 +247,7 @@ namespace Discord.Commands
                         builder.Summary = summary.Text;
                         break;
                     case OverrideTypeReaderAttribute typeReader:
-                        builder.TypeReader = GetTypeReader(service, paramType, typeReader.TypeReader);
+                        builder.TypeReader = GetTypeReader(service, paramType, typeReader.TypeReader, services);
                         break;
                     case ParamArrayAttribute _:
                         builder.IsMultiple = true;
@@ -285,7 +287,7 @@ namespace Discord.Commands
             }
         }
 
-        private static TypeReader GetTypeReader(CommandService service, Type paramType, Type typeReaderType)
+        private static TypeReader GetTypeReader(CommandService service, Type paramType, Type typeReaderType, IServiceProvider services)
         {
             var readers = service.GetTypeReaders(paramType);
             TypeReader reader = null;
@@ -296,7 +298,7 @@ namespace Discord.Commands
             }
 
             //We dont have a cached type reader, create one
-            reader = ReflectionUtils.CreateObject<TypeReader>(typeReaderType.GetTypeInfo(), service, EmptyServiceProvider.Instance);
+            reader = ReflectionUtils.CreateObject<TypeReader>(typeReaderType.GetTypeInfo(), service, services);
             service.AddTypeReader(paramType, reader);
 
             return reader;

src/Discord.Net.Commands/CommandService.cs

@@ -1,5 +1,3 @@
-using Discord.Commands.Builders;
-using Discord.Logging;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -8,6 +6,9 @@ using System.Linq;
 using System.Reflection;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Discord.Commands.Builders;
+using Discord.Logging;
 
 namespace Discord.Commands
 {
@@ -85,7 +86,8 @@ namespace Discord.Commands
                 var builder = new ModuleBuilder(this, null, primaryAlias);
                 buildFunc(builder);
 
-                var module = builder.Build(this);
+                var module = builder.Build(this, null);
+
                 return LoadModuleInternal(module);
             }
             finally
@@ -93,8 +95,8 @@ namespace Discord.Commands
                 _moduleLock.Release();
             }
         }
-        public Task<ModuleInfo> AddModuleAsync<T>() => AddModuleAsync(typeof(T));
-        public async Task<ModuleInfo> AddModuleAsync(Type type)
+        public Task<ModuleInfo> AddModuleAsync<T>(IServiceProvider services) => AddModuleAsync(typeof(T), services);
+        public async Task<ModuleInfo> AddModuleAsync(Type type, IServiceProvider services)
         {
             await _moduleLock.WaitAsync().ConfigureAwait(false);
             try
@@ -104,7 +106,7 @@ namespace Discord.Commands
                 if (_typedModuleDefs.ContainsKey(type))
                     throw new ArgumentException($"This module has already been added.");
 
-                var module = (await ModuleClassBuilder.BuildAsync(this, typeInfo).ConfigureAwait(false)).FirstOrDefault();
+                var module = (await ModuleClassBuilder.BuildAsync(this, services, typeInfo).ConfigureAwait(false)).FirstOrDefault();
 
                 if (module.Value == default(ModuleInfo))
                     throw new InvalidOperationException($"Could not build the module {type.FullName}, did you pass an invalid type?");
@@ -118,13 +120,13 @@ namespace Discord.Commands
                 _moduleLock.Release();
             }
         }
-        public async Task<IEnumerable<ModuleInfo>> AddModulesAsync(Assembly assembly)
+        public async Task<IEnumerable<ModuleInfo>> AddModulesAsync(Assembly assembly, IServiceProvider services)
         {
             await _moduleLock.WaitAsync().ConfigureAwait(false);
             try
             {
                 var types = await ModuleClassBuilder.SearchAsync(assembly, this).ConfigureAwait(false);
-                var moduleDefs = await ModuleClassBuilder.BuildAsync(types, this).ConfigureAwait(false);
+                var moduleDefs = await ModuleClassBuilder.BuildAsync(types, this, services).ConfigureAwait(false);
 
                 foreach (var info in moduleDefs)
                 {
@@ -224,7 +226,7 @@ namespace Discord.Commands
             var readers = _typeReaders.GetOrAdd(typeof(Nullable<>).MakeGenericType(valueType), x => new ConcurrentDictionary<Type, TypeReader>());
             var nullableReader = NullableTypeReader.Create(valueType, valueTypeReader);
             readers[nullableReader.GetType()] = nullableReader;
-        }  
+        }
         internal IDictionary<Type, TypeReader> GetTypeReaders(Type type)
         {
             if (_typeReaders.TryGetValue(type, out var definedTypeReaders))
@@ -277,92 +279,94 @@ namespace Discord.Commands
         public async Task<IResult> ExecuteAsync(ICommandContext context, string input, IServiceProvider services = null, MultiMatchHandling multiMatchHandling = MultiMatchHandling.Exception)
         {
             services = services ?? EmptyServiceProvider.Instance;
-
-            var searchResult = Search(context, input);
-            if (!searchResult.IsSuccess)
-                return searchResult;
-
-            var commands = searchResult.Commands;
-            var preconditionResults = new Dictionary<CommandMatch, PreconditionResult>();
-
-            foreach (var match in commands)
+            using (var scope = services.CreateScope())
             {
-                preconditionResults[match] = await match.Command.CheckPreconditionsAsync(context, services).ConfigureAwait(false);
-            }
+                var searchResult = Search(context, input);
+                if (!searchResult.IsSuccess)
+                    return searchResult;
 
-            var successfulPreconditions = preconditionResults
-                .Where(x => x.Value.IsSuccess)
-                .ToArray();
+                var commands = searchResult.Commands;
+                var preconditionResults = new Dictionary<CommandMatch, PreconditionResult>();
 
-            if (successfulPreconditions.Length == 0)
-            {
-                //All preconditions failed, return the one from the highest priority command
-                var bestCandidate = preconditionResults
-                    .OrderByDescending(x => x.Key.Command.Priority)
-                    .FirstOrDefault(x => !x.Value.IsSuccess);
-                return bestCandidate.Value;
-            }
+                foreach (var match in commands)
+                {
+                    preconditionResults[match] = await match.Command.CheckPreconditionsAsync(context, scope.ServiceProvider).ConfigureAwait(false);
+                }
 
-            //If we get this far, at least one precondition was successful.
+                var successfulPreconditions = preconditionResults
+                    .Where(x => x.Value.IsSuccess)
+                    .ToArray();
 
-            var parseResultsDict = new Dictionary<CommandMatch, ParseResult>();
-            foreach (var pair in successfulPreconditions)
-            {
-                var parseResult = await pair.Key.ParseAsync(context, searchResult, pair.Value, services).ConfigureAwait(false);
+                if (successfulPreconditions.Length == 0)
+                {
+                    //All preconditions failed, return the one from the highest priority command
+                    var bestCandidate = preconditionResults
+                        .OrderByDescending(x => x.Key.Command.Priority)
+                        .FirstOrDefault(x => !x.Value.IsSuccess);
+                    return bestCandidate.Value;
+                }
 
-                if (parseResult.Error == CommandError.MultipleMatches)
+                //If we get this far, at least one precondition was successful.
+
+                var parseResultsDict = new Dictionary<CommandMatch, ParseResult>();
+                foreach (var pair in successfulPreconditions)
                 {
-                    IReadOnlyList<TypeReaderValue> argList, paramList;
-                    switch (multiMatchHandling)
+                    var parseResult = await pair.Key.ParseAsync(context, searchResult, pair.Value, scope.ServiceProvider).ConfigureAwait(false);
+
+                    if (parseResult.Error == CommandError.MultipleMatches)
                     {
-                        case MultiMatchHandling.Best:
-                            argList = parseResult.ArgValues.Select(x => x.Values.OrderByDescending(y => y.Score).First()).ToImmutableArray();
-                            paramList = parseResult.ParamValues.Select(x => x.Values.OrderByDescending(y => y.Score).First()).ToImmutableArray();
-                            parseResult = ParseResult.FromSuccess(argList, paramList);
-                            break;
+                        IReadOnlyList<TypeReaderValue> argList, paramList;
+                        switch (multiMatchHandling)
+                        {
+                            case MultiMatchHandling.Best:
+                                argList = parseResult.ArgValues.Select(x => x.Values.OrderByDescending(y => y.Score).First()).ToImmutableArray();
+                                paramList = parseResult.ParamValues.Select(x => x.Values.OrderByDescending(y => y.Score).First()).ToImmutableArray();
+                                parseResult = ParseResult.FromSuccess(argList, paramList);
+                                break;
+                        }
                     }
-                }
 
-                parseResultsDict[pair.Key] = parseResult;
-            }
+                    parseResultsDict[pair.Key] = parseResult;
+                }
 
-            // Calculates the 'score' of a command given a parse result
-            float CalculateScore(CommandMatch match, ParseResult parseResult)
-            {
-                float argValuesScore = 0, paramValuesScore = 0;
-                
-                if (match.Command.Parameters.Count > 0)
+                // Calculates the 'score' of a command given a parse result
+                float CalculateScore(CommandMatch match, ParseResult parseResult)
                 {
-                    var argValuesSum = parseResult.ArgValues?.Sum(x => x.Values.OrderByDescending(y => y.Score).FirstOrDefault().Score) ?? 0;
-                    var paramValuesSum = parseResult.ParamValues?.Sum(x => x.Values.OrderByDescending(y => y.Score).FirstOrDefault().Score) ?? 0;
+                    float argValuesScore = 0, paramValuesScore = 0;
+
+                    if (match.Command.Parameters.Count > 0)
+                    {
+                        var argValuesSum = parseResult.ArgValues?.Sum(x => x.Values.OrderByDescending(y => y.Score).FirstOrDefault().Score) ?? 0;
+                        var paramValuesSum = parseResult.ParamValues?.Sum(x => x.Values.OrderByDescending(y => y.Score).FirstOrDefault().Score) ?? 0;
 
-                    argValuesScore = argValuesSum / match.Command.Parameters.Count;
-                    paramValuesScore = paramValuesSum / match.Command.Parameters.Count;
+                        argValuesScore = argValuesSum / match.Command.Parameters.Count;
+                        paramValuesScore = paramValuesSum / match.Command.Parameters.Count;
+                    }
+
+                    var totalArgsScore = (argValuesScore + paramValuesScore) / 2;
+                    return match.Command.Priority + totalArgsScore * 0.99f;
                 }
 
-                var totalArgsScore = (argValuesScore + paramValuesScore) / 2;
-                return match.Command.Priority + totalArgsScore * 0.99f;
-            }
+                //Order the parse results by their score so that we choose the most likely result to execute
+                var parseResults = parseResultsDict
+                    .OrderByDescending(x => CalculateScore(x.Key, x.Value));
 
-            //Order the parse results by their score so that we choose the most likely result to execute
-            var parseResults = parseResultsDict
-                .OrderByDescending(x => CalculateScore(x.Key, x.Value));
+                var successfulParses = parseResults
+                    .Where(x => x.Value.IsSuccess)
+                    .ToArray();
 
-            var successfulParses = parseResults
-                .Where(x => x.Value.IsSuccess)
-                .ToArray();
+                if (successfulParses.Length == 0)
+                {
+                    //All parses failed, return the one from the highest priority command, using score as a tie breaker
+                    var bestMatch = parseResults
+                        .FirstOrDefault(x => !x.Value.IsSuccess);
+                    return bestMatch.Value;
+                }
 
-            if (successfulParses.Length == 0)
-            {
-                //All parses failed, return the one from the highest priority command, using score as a tie breaker
-                var bestMatch = parseResults
-                    .FirstOrDefault(x => !x.Value.IsSuccess);
-                return bestMatch.Value;
+                //If we get this far, at least one parse was successful. Execute the most likely overload.
+                var chosenOverload = successfulParses[0];
+                return await chosenOverload.Key.ExecuteAsync(context, chosenOverload.Value, scope.ServiceProvider).ConfigureAwait(false);
             }
-
-            //If we get this far, at least one parse was successful. Execute the most likely overload.
-            var chosenOverload = successfulParses[0];
-            return await chosenOverload.Key.ExecuteAsync(context, chosenOverload.Value, services).ConfigureAwait(false);
         }
     }
 }

src/Discord.Net.Commands/CommandServiceConfig.cs

@@ -1,4 +1,6 @@
-namespace Discord.Commands
+using System;
+
+namespace Discord.Commands
 {
     public class CommandServiceConfig
     {
@@ -18,5 +20,11 @@
 
         /// <summary> Determines whether extra parameters should be ignored. </summary>
         public bool IgnoreExtraArgs { get; set; } = false;
+
+        ///// <summary> Gets or sets the <see cref="IServiceProvider"/> to use. </summary>
+        //public IServiceProvider ServiceProvider { get; set; } = null;
+
+        ///// <summary> Gets or sets a factory function for the <see cref="IServiceProvider"/> to use. </summary>
+        //public Func<CommandService, IServiceProvider> ServiceProviderFactory { get; set; } = null;
     }
 }

src/Discord.Net.Commands/IModuleBase.cs

@@ -1,4 +1,6 @@
-namespace Discord.Commands
+using Discord.Commands.Builders;
+
+namespace Discord.Commands
 {
     internal interface IModuleBase
     {
@@ -7,5 +9,7 @@
         void BeforeExecute(CommandInfo command);
         
         void AfterExecute(CommandInfo command);
+
+        void OnModuleBuilding(CommandService commandService, ModuleBuilder builder);
     }
 }

src/Discord.Net.Commands/Info/ModuleInfo.cs

@@ -2,7 +2,7 @@ using System;
 using System.Linq;
 using System.Collections.Generic;
 using System.Collections.Immutable;
-
+using System.Reflection;
 using Discord.Commands.Builders;
 
 namespace Discord.Commands
@@ -13,6 +13,7 @@ namespace Discord.Commands
         public string Name { get; }
         public string Summary { get; }
         public string Remarks { get; }
+        public string Group { get; }
 
         public IReadOnlyList<string> Aliases { get; }
         public IReadOnlyList<CommandInfo> Commands { get; }
@@ -22,21 +23,26 @@ namespace Discord.Commands
         public ModuleInfo Parent { get; }
         public bool IsSubmodule => Parent != null;
 
-        internal ModuleInfo(ModuleBuilder builder, CommandService service, ModuleInfo parent = null)
+        //public TypeInfo TypeInfo { get; }
+
+        internal ModuleInfo(ModuleBuilder builder, CommandService service, IServiceProvider services, ModuleInfo parent = null)
         {
             Service = service;
 
             Name = builder.Name;
             Summary = builder.Summary;
             Remarks = builder.Remarks;
+            Group = builder.Group;
             Parent = parent;
 
+            //TypeInfo = builder.TypeInfo;
+
             Aliases = BuildAliases(builder, service).ToImmutableArray();
             Commands = builder.Commands.Select(x => x.Build(this, service)).ToImmutableArray();
             Preconditions = BuildPreconditions(builder).ToImmutableArray();
             Attributes = BuildAttributes(builder).ToImmutableArray();
 
-            Submodules = BuildSubmodules(builder, service).ToImmutableArray();
+            Submodules = BuildSubmodules(builder, service, services).ToImmutableArray();
         }
 
         private static IEnumerable<string> BuildAliases(ModuleBuilder builder, CommandService service)
@@ -66,12 +72,12 @@ namespace Discord.Commands
             return result;
         }
 
-        private List<ModuleInfo> BuildSubmodules(ModuleBuilder parent, CommandService service)
+        private List<ModuleInfo> BuildSubmodules(ModuleBuilder parent, CommandService service, IServiceProvider services)
         {
             var result = new List<ModuleInfo>();
 
             foreach (var submodule in parent.Modules)
-                result.Add(submodule.Build(service, this));
+                result.Add(submodule.Build(service, services, this));
 
             return result;
         }

src/Discord.Net.Commands/ModuleBase.cs

@@ -1,5 +1,6 @@
-using System;
+using System;
 using System.Threading.Tasks;
+using Discord.Commands.Builders;
 
 namespace Discord.Commands
 {
@@ -23,15 +24,18 @@ namespace Discord.Commands
         {
         }
 
+        protected virtual void OnModuleBuilding(CommandService commandService, ModuleBuilder builder)
+        {
+        }
+
         //IModuleBase
         void IModuleBase.SetContext(ICommandContext context)
         {
             var newValue = context as T;
             Context = newValue ?? throw new InvalidOperationException($"Invalid context type. Expected {typeof(T).Name}, got {context.GetType().Name}");
         }
-
         void IModuleBase.BeforeExecute(CommandInfo command) => BeforeExecute(command);
-
         void IModuleBase.AfterExecute(CommandInfo command) => AfterExecute(command);
+        void IModuleBase.OnModuleBuilding(CommandService commandService, ModuleBuilder builder) => OnModuleBuilding(commandService, builder);
     }
 }