Zephyrus Framework

Zephyrus is a slash command framework meant to be used by twilight

Note: The framework is new and might have some problems, all contributions are appreciated

This crate is independent from the twilight ecosystem

The framework is experimental and the API might change.

Zephyrus is a command framework which uses slash commands, it mainly offers variable argument parsing.

Parsing is done with the Parse trait, so users can implement the parsing of their own types.

Argument parsing is done in a named way, this means the argument name shown on discord gets parsed into the arguments named the same way in the handler function.

The framework itself doesn't spawn any tasks by itself, so you might want to wrap it in an Arc and call tokio::spawn before calling the .process method.

Usage example

use std::sync::Arc;
use futures::StreamExt;
use twilight_gateway::{Cluster, cluster::Events};
use twilight_http::Client;
use twilight_model::{application::callback::{CallbackData, InteractionResponse}, gateway::{event::Event, Intents}, id::{ApplicationId, GuildId}};
use zephyrus::prelude::*;

#[command]
#[description = "Says hello"]
async fn hello(ctx: &SlashContext<()>) -> CommandResult {
    ctx.interaction_client.create_response(
        ctx.interaction.id,
        &ctx.interaction.token,
        &InteractionResponse {
            kind: InteractionResponseType::ChannelMessageWithSource,
            data: Some(InteractionResponseData {
                content: Some(String::from("Hello world")),
                ..Default::default()
            })
        }
    ).exec().await?;

    Ok(())
}

async fn handle_events(http_client: Arc<Client>, mut events: Events) {
    let framework = Arc::new(Framework::builder(http_client, ())
        .command(hello)
        .build());

    // Zephyrus can register commands in guilds or globally.
    framework.register_guild_commands(GuildId::new("<GUILD_ID>").unwrap()).await.unwrap();

    while let Some((_, event)) = events.next().await {
        match event {
            Event::InteractionCreate(i) => {
                let clone = Arc::clone(&framework);
                tokio::spawn(async move {
                    let inner = i.0;
                    clone.process(inner).await;
                });
            },
            _ => (),
        }
    }
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let token = std::env::var("DISCORD_TOKEN")?;
    let client = Arc::new(Client::builder().token(token.clone()).build());

    let (cluster, events) = Cluster::builder(token, Intents::empty())
        .http_client(Arc::clone(&client))
        .build()
        .await?;

    cluster.up().await;
    handle_events(client, events).await;

    Ok(())
}

Usage guide

Creating commands

Every command is an async function, having always as the first parameter a &SlashContext<T>

#[command]
#[description = "This is the description of the command"]
async fn command(
    ctx: &SlashContext</* Your type of context*/>, // The context must always be the first parameter.
    #[description = "A description for the argument"] some_arg: String,
    #[rename = "other_arg"] #[description = "other description"] other: Option<UserId>
) -> CommandResult 
{
    // Command body
    
    Ok(())
}

Command functions

Command functions must include a description attribute, which will be seen in discord when the user tries to use the command.

The #[command] attribute also allows to rename the command by passing the name of the command to the attribute like #[command("Command name here")]. If the name is not provided, the command will use the function name.

Command arguments

Command arguments are very similar to command functions, they also need a #[description] attribute that will be seen in discord by the user when filling up the command argument.

As shown in the example, a #[rename] attribute can also be used, this will change the name of the argument seen in discord. If the attribute is not used, the argument will have the same name as in the function.

Important: All command functions must have as the first parameter a &SlashContext<T>

Setting choices as command arguments

Choices are a very useful feature of slash commands, allowing the developer to set some choices from which the user has to choose.

Zephyrus allows doing this in an easy way, to allow this, a derive macro is provided by the framework. This macro is named the same way as Parse trait and can only be used in enums to define the options. Renaming is also allowed here by using the #[rename] attribute and allows to change the option name seen in discord.

#[derive(Parse)]
enum Choices {
    First,
    Second,
    Third,
    #[rename = "Forth"]
    Other
}

#[command]
#[description = "Some description"]
async fn choices(
    ctx: &SlashContext<()>,
    #[description = "Some description"] choice: Choices
) -> CommandResult
{
    // Command body
    Ok(())
}

Autocompleting commands

Autocomplete user input is made easy with Zephyrus, just use the autocomplete macro provided by the framework.

Here, take a look at this example. We'll use as the base an empty command like this

#[command]
#[description = "Some description"]
async fn some_command(
    ctx: &SlashCommand</* Some type */>,
    #[autocomplete = "autocomplete_arg"] #[description = "Some description"] arg: String
) -> CommandResult
{
    // Logic goes here
    Ok(())
}

As you may have noticed, we added an autocomplete attribute to the argument arg. The input specified on it must point to a function marked with the #[autocomplete] attribute like this one:

#[autocomplete]
async fn autocomplete_arg(ctx: AutocompleteContext</* Some type */>) -> Option<InteractionResponseData> {
    // Function body
}

Autocompleting functions must have an AutocompleteContext<T> as the sole parameter, it allows you to access to the data stored at the framework while also allowing you to access the raw interaction, the framework's http client and the user input, if exists.

Permissions

To specify required permissions to run a command, just use the #[required_permissions] attribute when declaring a command, or the .required_permissions method when declaring a command group.

The attribute accepts as input a comma separated list of twilight's permissions. Let's take a look at what it would look like to create a command needing MANAGE_CHANNELS and MANAGE_MESSAGES permissions:

#[command]
#[description = "Super cool command"]
#[required_permissions(MANAGE_CHANNELS, MANAGE_MESSAGES)]
async fn super_cool_command(ctx: &SlashContext</* Your type */>) -> CommandResult {
    // Body
    Ok(())
}

Command Groups

Zephyrus supports both SubCommands and SubCommandGroups by default.

To give examples, let's say we have created the following command:

#[command]
#[description = "Something"]
async fn something(ctx: &SlashContext</* Your type */>) -> CommandResult {
    // Command block
    Ok(())
}

With this we can now create both subcommands and subcommand groups

Creating subcommands

To create a subcommand you need to create a group, then you can add all the subcommands.

#[tokio::main]
async fn main() {
    let framework = Framework::builder()
        .group(|g| {
            g.name("<GROUP_NAME>")
                .description("<GROUP_DESCRIPTION>")
                .add_command(something)
                .add_command(..)
                ..
        })
        .build();
}

Creating subcommand groups

Subcommand groups are very similar to subcommands, they are created almost the same way, but instead of using .add_command directly, we have to use .group before to register a group.

#[tokio::main]
async fn main() {
    let framework = Framework::builder()
        .group(|g| {
            g.name("<GROUP_NAME>")
                .description("<GROUP_DESCRIPTION>")
                .group(|sub| { // With this we have created a subcommand group.
                    sub.name("<SUBGROUP_NAME>")
                        .description("<SUBGROUP_DESCRIPTION>")
                        .add_command(something)
                        .add_command(..)
                        ..
                })
        })
        .build();
}

Hooks

There are two hooks available, before and after.

Before

The before hook is triggered before the command and has to return a bool indicating if the command should be executed or not.

#[before]
async fn before_check(ctx: &SlashContext</*Your type*/>, command_name: &str) -> bool {
    // Do something
    
    true // <- if we return true, the command will be executed normally.
}

After

The after hook is triggered after the command execution and it provides the result of the command.

#[after]
async fn after_handler(ctx: &SlashContext</* Your type */>, command_name: &str, result: CommandResult) {
    // Do something with the result.
}