Discord.Net/docs/guides/int_framework/intro.md

• Getting Started
• • Modules
  • Commands
  • Slash Commands
  • • Parameters
    • • Optional Parameters
      • Parameter Summary
      • Parameter Choices
      • Channel Types
      • Min/Max Value
  • User Commands
  • Message Commands
  • Component Interaction Commands
  • Select Menus
  • Autocomplete Commands
  • Interaction Context
  • Loading Modules
  • Resolving Module Dependencies
  • Module Groups
  • Executing Commands
  • Registering Commands to Discord
  • Interaction Utility
  • Webhook Based Interactions

Getting Started

The Interaction Service provides an attribute based framework for creating Discord Interaction handlers.

To start using the Interaction Service, you need to create a service instance.
Optionally you can provide the InteractionService constructor with a
InteractionServiceConfig to change the services behaviour to suit your needs.

...
// _client here is DiscordSocketClient.
// A different approach to passing in a restclient is also possible.
var _interactionService = new InteractionService(_client.Rest);

...

Modules

Attribute based Interaction handlers must be defined within a command module class.
Command modules are responsible for executing the Interaction handlers and providing them with the necessary execution info and helper functions.

Command modules are transient objects.
A new module instance is created before a command execution starts then it will be disposed right after the method returns.

Every module class must:

• be public
• inherit InteractionModuleBase

Optionally you can override the included :

• OnModuleBuilding (executed after the module is built)
• BeforeExecute (executed before a command execution starts)
• AfterExecute (executed after a command execution concludes)

methods to configure the modules behaviour.

Every command module exposes a set of helper methods, namely:

• RespondAsync() => Respond to the interaction
• FollowupAsync() => Create a followup message for an interaction
• ReplyAsync() => Send a message to the origin channel of the interaction
• DeleteOriginalResponseAsync() => Delete the original interaction response

Commands

Valid Interaction Commands must comply with the following requirements:

	return type	max parameter count	allowed parameter types	attribute
Slash Command	Task/Task<RuntimeResult>	25	any*	[SlashCommand]
User Command	Task/Task<RuntimeResult>	1	Implementations of IUser	[UserCommand]
Message Command	Task/Task<RuntimeResult>	1	Implementations of IMessage	[MessageCommand]
Component Interaction Command	Task/Task<RuntimeResult>	inf	string or string[]	[ComponentInteraction]
Autocomplete Command	Task/Task<RuntimeResult>	-	-	[AutocompleteCommand]

[!NOTE]
a TypeConverter that is capable of parsing type in question must be registered to the InteractionService instance.
You should avoid using long running code in your command module.
Depending on your setup, long running code may block the Gateway thread of your bot, interrupting its connection to Discord.

Slash Commands

Slash Commands are created using the SlashCommandAttribute.
Every Slash Command must declare a name and a description.
You can check Discords Application Command Naming Guidelines
here.

[!code-csharpSlash Command]

Parameters

Slash Commands can have up to 25 method parameters. You must name your parameters in accordance with
Discords Naming Guidelines.
InteractionService also features a pascal casing seperator for formatting parameter names with
pascal casing into Discord compliant parameter names('parameterName' => 'parameter-name').
By default, your methods can feature the following parameter types:

• Implementations of IUser
• Implementations of IChannel
• Implementations of IRole
• Implementations of IMentionable
• string
• float, double, decimal
• bool
• char
• sbyte, byte
• int16, int32, int64
• uint16, uint32, uint64
• enum (Values are registered as multiple choice options and are enforced by Discord. Use [HideAttribute] on enum values to prevent them from getting registered.)
• DateTime
• TimeSpan

---

*You can use more specialized implementations of IChannel to restrict the allowed channel types for a channel type option.

interface	Channel Type
IStageChannel	Stage Channels
IVoiceChannel	Voice Channels
IDMChannel	DM Channels
IGroupChannel	Group Channels
ICategory Channel	Category Channels
INewsChannel	News Channels
IThreadChannel	Public, Private, News Threads
ITextChannel	Text Channels

---

Optional Parameters

Parameters with default values (ie. int count = 0) will be displayed as optional parameters on Discord Client.

Parameter Summary

By using the SummaryAttribute you can customize the displayed name and description of a parameter

[!code-csharpSummary Attribute]

Parameter Choices

ChoiceAttribute can be used to add choices to a parameter.

[!code-csharpChoice Attribute]

This Slash Command will be displayed exactly the same as the previous example.

Channel Types

Channel types for an IChannel parameter can also be restricted using the ChannelTypesAttribute.

[!code-csharpChannel Attribute]

In this case, user can only input Stage Channels and Text Channels to this parameter.

Min/Max Value

You can specify the permitted max/min value for a number type parameter using the MaxValueAttribute and MinValueAttribute.

User Commands

A valid User Command must have the following structure:

[!code-csharpUser Command]

[!WARNING]
User commands can only have one parameter and its type must be an implementation of IUser.

Message Commands

A valid Message Command must have the following structure:

[!code-csharpMessage Command]

[!WARNING]
Message commands can only have one parameter and its type must be an implementation of IMessage.

Component Interaction Commands

Component Interaction Commands are used to handle interactions that originate from Discord Message Components.
This pattern is particularly useful if you will be reusing a set a Custom IDs.

Component Interaction Commands support wild card matching,
by default * character can be used to create a wild card pattern.
Interaction Service will use lazy matching to capture the words corresponding to the wild card character.
And the captured words will be passed on to the command method in the same order they were captured.

[!code-csharpButton]

You may use as many wild card characters as you want.

[!NOTE]
If Interaction Service recieves a component interaction with player:play,rickroll custom id,
op will be play and name will be rickroll

Select Menus

Unlike button interactions, select menu interactions also contain the values of the selected menu items.
In this case, you should structure your method to accept a string array.

[!code-csharpDropdown]

[!NOTE]
Wildcards may also be used to match a select menu ID,
though keep in mind that the array containing the select menu values should be the last parameter.

Autocomplete Commands

Autocomplete commands must be parameterless methods. A valid Autocomplete command must have the following structure:

[!code-csharpAutocomplete Command]

Alternatively, you can use the AutocompleteHandlers to simplify this workflow.

Interaction Context

Every command module provides its commands with an execution context.
This context property includes general information about the underlying interaction that triggered the command execution.
The base command context.

You can design your modules to work with different implementation types of [IInteractionContext].
To achieve this, make sure your module classes inherit from the generic variant of the InteractionModuleBase.

[!NOTE]
Context type must be consistent throughout the project, or you will run into issues during runtime.

The InteractionService ships with 4 different kinds of InteractionContext:

1. InteractionContext]: A bare-bones execution context consisting of only implementation neutral interfaces
2. SocketInteractionContext: An execution context for use with DiscordSocketClient. Socket entities are exposed in this context without the need of casting them.
3. ShardedInteractionContext: [DiscordShardedClient] variant of the SocketInteractionContext
4. RestInteractionContext: An execution context designed to be used with a DiscordRestClient and webhook based interactions pattern

You can create custom Interaction Contexts by implementing the [IInteractionContext] interface.

One problem with using the concrete type InteractionContexts is that you cannot access the information that is specific to different interaction types without casting. Concrete type interaction contexts are great for creating shared interaction modules but you can also use the generic variants of the built-in interaction contexts to create interaction specific interaction modules.

[!INFO]
Message component interactions have access to a special method called UpdateAsync() to update the body of the method the interaction originated from.
Normally this wouldn't be accessable without casting the Context.Interaction.

[!code-csharpContext Example]

Loading Modules

InteractionService can automatically discover and load modules that inherit InteractionModuleBase from an Assembly.
Call InteractionService.AddModulesAsync() to use this functionality.

[!NOTE]
You can also manually add Interaction modules using the InteractionService.AddModuleAsync()
method by providing the module type you want to load.

Resolving Module Dependencies

Module dependencies are resolved using the Constructor Injection and Property Injection patterns.
Meaning, the constructor parameters and public settable properties of a module will be assigned using the IServiceProvider.
For more information on dependency injection, read the DependencyInjection guides.

[!NOTE]
On every command execution, module dependencies are resolved using a new service scope which allows you to utilize scoped service instances, just like in Asp.Net.
Including the precondition checks, every module method is executed using the same service scope and service scopes are disposed right after the AfterExecute method returns.

Module Groups

Module groups allow you to create sub-commands and sub-commands groups.
By nesting commands inside a module that is tagged with GroupAttribute you can create prefixed commands.

[!WARNING]
Although creating nested module stuctures are allowed,
you are not permitted to use more than 2 GroupAttribute's in module hierarchy.

Executing Commands

Any of the following socket events can be used to execute commands:

• InteractionCreated
• ButtonExecuted
• SelectMenuExecuted
• AutocompleteExecuted
• UserCommandExecuted
• MessageCommandExecuted

Commands can be either executed on the gateway thread or on a seperate thread from the thread pool. This behaviour can be configured by changing the RunMode property of InteractionServiceConfig or by setting the runMode parameter of a command attribute.

You can also configure the way InteractionService executes the commands.
By default, commands are executed using ConstructorInfo.Invoke() to create module instances and
MethodInfo.Invoke() method for executing the method bodies.
By setting, InteractionServiceConfig.UseCompiledLambda to true, you can make InteractionService create module instances and execute commands using
Compiled Lambda expressions. This cuts down on command execution time but it might add some memory overhead.

Time it takes to create a module instance and execute a Task.Delay(0) method using the Reflection methods compared to Compiled Lambda expressions:

Method	Mean	Error	StdDev
ReflectionInvoke	225.93 ns	4.522 ns	7.040 ns
CompiledLambda	48.79 ns	0.981 ns	1.276 ns

Registering Commands to Discord

Application commands loaded to the Interaction Service can be registered to Discord using a number of different methods.
In most cases RegisterCommandsGloballyAsync() and RegisterCommandsToGuildAsync() are the methods to use.
Command registration methods can only be used after the gateway client is ready or the rest client is logged in.

[!code-csharpRegistering Commands Example]

Methods like AddModulesToGuildAsync(), AddCommandsToGuildAsync(), AddModulesGloballyAsync() and AddCommandsGloballyAsync()
can be used to register cherry picked modules or commands to global/guild scopes.

[!NOTE]
In debug environment, since Global commands can take up to 1 hour to register/update,
it is adviced to register your commands to a test guild for your changes to take effect immediately.
You can use preprocessor directives to create a simple logic for registering commands as seen above

Interaction Utility

Interaction Service ships with a static InteractionUtiliy
class which contains some helper methods to asynchronously waiting for Discord Interactions.
For instance, WaitForInteractionAsync() method allows you to wait for an Interaction for a given amount of time.
This method returns the first encountered Interaction that satisfies the provided predicate.

[!WARNING]
If you are running the Interaction Service on RunMode.Sync you should avoid using this method in your commands,
as it will block the gateway thread and interrupt your bots connection.

Webhook Based Interactions

Instead of using the gateway to recieve Discord Interactions, Discord allows you to recieve Interaction events over Webhooks.
Interaction Service also supports this Interaction type but to be able to
respond to the Interactions within your command modules you need to perform the following:

• Make your modules inherit RestInteractionModuleBase
• Set the ResponseCallback property of InteractionServiceConfig so that the ResponseCallback
  delegate can be used to create HTTP responses from a deserialized json object string.
• Use the interaction endpoints of the module base instead of the interaction object (ie. RespondAsync(), FollowupAsync()...).