README

JADL Command Handler

This new version of the command handler is WIP and not stable, use with caution.

Prerequisites

If you're going to use the decorators built into the command handler, make sure to set "experimentalDecorators": true in your tsconfig.json

Creating a Command Handler

Create a command handler with the CommandHandler class

import { CommandHandler } from '@jadl/cmd'

import { WaveCommand } from './commands/WaveCommand' // example command

const commands = new CommandHandler(worker, [
  // your command classes
  WaveCommand
])

Creating a command

Commands are classes that will be filled with decorator to dictate their functionality

Our main decorator for a command is @Command(name: string, description: string)

Once you've declared your class, you create a method to run the command through, and mark it with a @Run() decorator

You can return a traditional MessageTypes and it will respond to the command with that. Here's an example;

import { Command } from '@jadl/cmd'

@Command('wave', 'Wave at someone!') // sets the command name to /wave
export class WaveCommand {
  @Run() // marks this method as the main running command
  wave () {
    return 'Hello!'
  }
}

Simplest command in the book. Lets get a bit more advanced.

Accessing data with parameter decorators

Using parameter decorators is how we access all of our important data, to make your command a real command

Many of them exist and allow for adding and using interaction options, or just accessing your normal data objects

e.g let's add a user via the Options.User decorator. This will create a Discord interaction user option

import { Command, Run, Worker, Author } from '@jadl/cmd'
import { Embed } from '@jadl/embed' // optional, but used for embeds!

@Command('hello', 'Say hello!')
export class HelloCommand {
  @Run()
  hello (
    @Worker() worker: Bot, // creates a paramater that is your worker
    @Author() author: APIUser // gets the user who sent the command
  ) {
    // you can now use this parameter as it's actual value! making it super easy to do what you need to do
    return new Embed()
      .description(`Hey <@${author.id}>! Thanks for saying hi! My name is ${worker.user.username}!`)
  }
}

// note, discord-api-types is EXTREMELY useful and will let you add types for all of these

Some helpful decorators:

@Worker, gets the main worker
@Interaction gets the interaction object
@Guild gets the guild
@Author gets the running user
@Member gets the running member
@Me gets the worker's member in this guild

(many more to come) // WIP

Creating options

The @Options.[] decorator is used to apply options to a command. For example @Options.String('name', 'description', { options })

e.g let's add a user via the Options.User decorator. This will create a Discord interaction user option

import { Command, Run, Options } from '@jadl/cmd'
import { Embed } from '@jadl/embed'

@Command('wave', 'Wave at someone!')
export class WaveCommand {
  @Run()
  wave (
    @Options.User('user', 'User to wave at', {
      required: true
    }) user: APIUser // creates an option accepting type user
  ) {
    // you can now use this parameter as it's actual value! making it super easy to do what you need to do
    return new Embed()
      .description(`Hey <@${user.id}>! Someone waved at you`)
  }
}

Targets & message/user commands

You can create a user or message command by passing the type of command you'd like to the @Command() 3rd parameter

And then you can use the @Targets decorator as a value for those targets. Be careful to make sure to use the correct target for your command

e.g lets make our wave command a user command!

import { Command, Run, Targets, Author } from '@jadl/cmd'
import { Embed } from '@jadl/embed'

import { ApplicationCommandType } from 'discord-api-types'

@Command('Wave at user', undefined, ApplicationCommandType.User)
export class WaveCommand {
  @Run()
  wave (
    @Targets.User() user: APIUser, // gets the user who the command was ran ON
    @Author() author: APIUser // gets the user who the command was ran FROM
  ) {
    return new Embed()
      .description(`Hey <@${user.id}>! <@${author.id}> waved at you!`)
  }
}

Middleware / interceptor decorators

With decorators it's super easy to create and use decorator for specific commands. There's a few built in. For example @UserPerms()

@Command('ban', 'Ban a user')
class BanCommand {
  @Run()
  @UserPerms('administrator') // this will require the user has the administrator permission
  run () {
    // run ban
  }
}

Creating your own

You can also make your own decorators with the Decorators object

There are 3 types of decorators

Base Decorators

Base decorators go above the command class similar to the @Command() decorator. These are mostly used for internal things, but it's available

You can create this with the Decorators.createBaseDecorator() method

Command Decorators

Command decorators are the decorators that go over the method being ran, and are generally used as middleware / interceptors, or just defining extra metadata about the command

You can create these with the Decorators.createCommandDecorator() method

e.g let's create a specific user only decorator

src/decorators/UserLocked.ts

import { Decorators } from '@jadl/cmd' // global utility for everything decorators

export const UserLocked = Decorators.createCommandDecorator<[
  // options
  userId: string
]>(([userId], cmd) => {
  // Use the canRun array of functions
  cmd.canRun.push((interaction, handler) => { // interaction being the raw object
    // return a boolean of whether or not the author is the user locked
    return interaction.user.id === userId
  })
  // you can also use the onRun array of functions to disregard returning and errors
})

You can now use this in your command like so

import { UserLocked } from '../decorators/UserLocked'

@Command('wave', 'Wave at someone!')
export class WaveCommand {
  @Run()
  @UserLocked('277183033344524288') // this will now apply the above canRun method
  run () {
    return 'Wave!' // only ran if the user matches the user locked to this command
  }
}

Parameter decorators

Parameter decorators are used to pass data to the running method when a command has been ran

The essential way this works is that you're giving the command handler a function that will be ran and positioned to your method based on the parameter

You can create these with the Decorators.createParameterDecorator() method

e.g let's make a database decorator

src/decorators/Db.ts

import { Decorators } from '@jadl/cmd'

// you can add options the same was as was done above, however we don't need that here
export const Db = Decorators.createParameterDecorator((options) => {
  return async (interaction, { worker }) => { // this method is ran EVERYTIME a command is ran, and it's return value is what shows up on the parameter for your method
    return await worker.db.guildSettings.get(interaction.guild_id) // returns the guild's database
  }
})

Now we can use the @Db() decorator shorthand in our method

import { Db } from '../decorators/Db'

@Command('wave', 'Wave at someone!')
export class WaveCommand {
  @Run()
  wave (
    @Db() db: GuildSettings, // makes our db parameter
    @Author() author: APIUser // and you can add as many of these params as you'd like!
  ) {
    // and now db will be whatever was returned in the Db decorator!
    if (!db.users.includes(author.id)) return "You can't do that!"

    return 'Wave!'
  }
}

Usage no npm install needed!