@SlashOption

A slash command can have multiple options (parameters)

query is an option in this image

Signature

SlashOption(options: SlashOptionOptions);

Declare an option

To declare an option you simply use the @SlashOption decorator before a method parameter

@Discord()
class Example {
  @Slash({ description: "add" })
  add(
    @SlashOption({
      description: "x value",
      name: "x",
      required: true,
      type: ApplicationCommandOptionType.Number,
    })
    x: number,
    @SlashOption({
      description: "y value",
      name: "y",
      required: true,
      type: ApplicationCommandOptionType.Number,
    })
    y: number,
    interaction: CommandInteraction,
  ) {
    interaction.reply(String(x + y));
  }
}

Create option using discord.js builders

import {
  SlashCommandBuilder,
  SlashCommandMentionableOption,
  User,
  type CommandInteraction,
} from "discord.js";
import { Discord, Slash, SlashOption } from "discordx";

const cmd = new SlashCommandBuilder()
  .setName("hello")
  .setDescription("Say hello!");

const user_option = new SlashCommandMentionableOption()
  .setName("user")
  .setDescription("Mention user to say hello to.")
  .setRequired(true);

@Discord()
export class Example {
  @Slash(cmd)
  async hello(
    @SlashOption(user_option) user: User,
    interaction: CommandInteraction,
  ): Promise<void> {
    await interaction.reply(`:wave: ${user}`);
  }
}

Transformer

Act as middleware for your parameters. Take a look at the following example to see how useful it is.

class Document {
  constructor(
    public input: string,
    public interaction: ChatInputCommandInteraction,
  ) {
    /*
      empty constructor
    */
  }

  async save(): Promise<void> {
    /*
      your logic to save input into database
    */

    await this.interaction.followUp(
      `${this.interaction.user} saved \`${this.input}\` into database`,
    );
  }
}

function DocumentTransformer(
  input: string,
  interaction: ChatInputCommandInteraction,
): Document {
  return new Document(input, interaction);
}

@Discord()
export class Example {
  @Slash({ description: "Save input into database", name: "save-input" })
  async withTransformer(
    @SlashOption(
      {
        description: "input",
        name: "input",
        required: true,
        type: ApplicationCommandOptionType.String,
      },
      DocumentTransformer,
    )
    doc: Document,
    interaction: ChatInputCommandInteraction,
  ): Promise<void> {
    await interaction.deferReply();
    doc.save();
  }
}

Autocomplete option

Autocomplete interactions allow your application to dynamically return option suggestions to a user as they type. - discord

Method - Resolver

When defining an autocomplete slash option, you can define a resolver for autocomplete inside @SlashOption to simplify things.

@SlashOption({
  autocomplete: function (
    interaction: AutocompleteInteraction
  ) {
      interaction.respond([
        { name: "option a", value: "a" },
        { name: "option b", value: "b" },
      ]);
  },
  description: "autocomplete",
  name: "autocomplete",
  required: true,
  type: ApplicationCommandOptionType.String,
})
input: string,

Method - Boolean

discordx will call your command handler with autocomplete interaction if you use boolean instead of resolver.

@SlashOption({
  autocomplete: true,
  description: "choice",
  name: "choice",
  required: true,
  type: ApplicationCommandOptionType.String,
}) input: string,
interaction: CommandInteraction | AutocompleteInteraction

Example - All Methods

@Discord()
class Example {
  myCustomText = "Hello discordx";

  @Slash({ description: "autocomplete" })
  autocomplete(
    @SlashOption({
      autocomplete: true,
      description: "option-a",
      name: "option-a",
      required: true,
      type: ApplicationCommandOptionType.String,
    })
    searchText: string,
    @SlashOption({
      autocomplete: function (
        this: Example,
        interaction: AutocompleteInteraction,
      ) {
        // The normal function has this (keyword), therefore class reference is available
        console.log(this.myCustomText);

        // resolver for option b
        interaction.respond([
          { name: "option c", value: "d" },
          { name: "option d", value: "c" },
        ]);
      },
      description: "option-b",
      name: "option-b",
      required: true,
      type: ApplicationCommandOptionType.String,
    })
    searchText2: string,
    @SlashOption({
      autocomplete: (interaction: AutocompleteInteraction) => {
        // This is not available for the arrow function, so there is no class reference
        interaction.respond([
          { name: "option e", value: "e" },
          { name: "option f", value: "f" },
        ]);
      },
      description: "option-c",
      name: "option-c",
      required: true,
      type: ApplicationCommandOptionType.String,
    })
    searchText3: string,
    interaction: CommandInteraction | AutocompleteInteraction,
  ): void {
    // If autocomplete is not handled above, it will be passed to handler (see option-a definition)
    if (interaction.isAutocomplete()) {
      const focusedOption = interaction.options.getFocused(true);
      // resolver for option a
      if (focusedOption.name === "option-a") {
        interaction.respond([
          { name: "option a", value: "a" },
          { name: "option b", value: "b" },
        ]);
      }
    } else {
      interaction.reply(`${searchText}-${searchText2}-${searchText3}`);
    }
  }
}

Manual typing

If you want to specify the type manually you can do it:

@Discord()
class Example {
  @Slash({ description: "Get id", name: "get-id" })
  getID(
    @SlashOption({
      description: "x",
      name: "x",
      required: true,
      type: ApplicationCommandOptionType.Mentionable,
    })
    mentionable: GuildMember | User | Role,
    interaction: CommandInteraction,
  ) {
    interaction.reply(mentionable.id);
  }
}

Autocompletion (Option's choices)

You can use the @SlashChoice decorator

Option order

You have to put required options before optional ones
Or you will get this error:

(node:64399) UnhandledPromiseRejectionWarning: DiscordAPIError: Invalid Form Body
options[1]: Required options must be placed before non-required options