Remora.Discord.Interactivity 3.0.18

Remora.Discord.Interactivity

This package provides a framework for creating interaction-driven entities using Discord's message components.

Structure

The library's design revolves around an MVC-like architecture, where your application provides and drives the model and controller, while Discord serves as the view.

A controller is implemented by creating a class that implements IInteractiveEntity, which in turn may access data from an arbitrary model of your choice (EF Core, in-memory data, external APIs, etc). This entity is then instantiated and invoked when your application receives a component interaction, and declares its interest in the interaction based on contextual data.

Interested entities (of which there may be several) are then allowed to perform their implemented functionality in order to update the model or view.

Usage

First, add the required services to the dependency injection container.

services.AddInteractivity();

In order to respond to incoming component interactions, declare a class that implements one or more interfaces related to the component type the entity wishes to provide business logic for (such as IButtonInteractiveEntity, ISelectMenuInteractiveEntity, or IModalInteractiveEntity).

Entities are transient services, so you may inject any other dependencies in normal fashion.

public class MyEntity : IButtonInteractiveEntity
{
    public Task<Result<bool>> IsInterestedAsync(ComponentType? componentType, string customID, CancellationToken ct = default)
    {
        // ...
    }
    
    public Task<Result> HandleInteractionAsync(IUser user, string customID, CancellationToken ct = default)
    {
        // ...
    }
}

These entities must then be registered with your dependency injection container.

services.AddInteractiveEntity<MyEntity>();

External model

If your controller manipulates data from an external model, it is up to you to appropriately synchronize access or inject relevant services into the entity.

In-memory model

If your controller only has simple needs, a built-in in-memory model may be used, wherein access to a shared object is controlled by Remora. Entities that wish to access the same in-memory model are executed sequentially, and changes made to the object are propagated between each entity.

Entities which wish to use this in-memory model must inherit from InMemoryPersistentInteractiveEntity<TData>, and messages associated with these entities must be sent via the InteractiveMessageService where an initial model state is provided.

public class MyInMemoryEntity : InMemoryPersistentInteractiveEntity, IButtonInteractiveEntity
{
    public string Nonce => _myContextualInformation.Nonce;

    public Task<Result<bool>> IsInterestedAsync(ComponentType? componentType, string customID, CancellationToken ct = default)
    {
        // ...
    }
    
    public Task<Result> HandleInteractionAsync(IUser user, string customID, CancellationToken ct = default)
    {
        // ...
        this.Data.DoSomething();
    }
}

The Nonce property is used to identify which shared object the entity wishes to act upon, and is usually formed from contextual information injected into the entity (such as a guild, channel, user, or message ID).

If the shared object should be deleted after the entity has finished executing, you may set the DeleteData property to true.

Note that the shared objects are not deleted automatically, and do not have a set lifetime. If you do not flag them for deletion at some point, they will persist indefinitely.