Logic & Condition Handling

This document summarizes how to handle business flows in Nezon. Each item links to detailed pages for deeper exploration.

1. Command – Text Commands

Use @Command() to create commands like *ping, *poll...

import { Command, AutoContext, SmartMessage } from "@n0xgg04/nezon";
import type { Nezon } from "@n0xgg04/nezon";

@Command({ name: "ping", aliases: ["pong"] })
export class PingCommand {
  async execute(@AutoContext() [message]: Nezon.AutoContext) {
    await message.reply(SmartMessage.text("pong!"));
  }
}

• Supports @Args() to get parameters.
• Can be organized into multiple handler modules (see apps/mebot).

👉 Details: Interaction → Command.

2. Component – Handle Button/Dropdown

Use @Component() with a pattern matching ButtonBuilder.setCustomId. You can inject:

• @ComponentParams() / @ComponentParams('id')
• @ComponentPayload() – raw payload
• @FormData() – form data included
• @AutoContext() – reply/update message

@Component({ pattern: '/poll/create' })
async onPollCreate(
  @FormData() form: Nezon.FormData | undefined,
  @AutoContext('message') message: Nezon.AutoContextType.Message,
) {
  await message.reply(
    SmartMessage.text(
      `Form Data:\n${JSON.stringify(form, null, 2)}`,
    ),
  );
}

👉 Details: Interaction → Component.

3. Button onClick

Don't want to create a separate @Component? You can attach an inline handler when building the button.

new ButtonBuilder()
  .setLabel("Vote")
  .setStyle(ButtonStyle.Success)
  .onClick(async ({ message, user, formData }) => {
    await message.reply(
      SmartMessage.text(
        `User ${user?.username} chose: ${formData?.option ?? "N/A"}`
      )
    );
  });

Context is normalized:

• message: ManagedMessage
• channel: TextChannel
• user: User
• clan: Clan
• client: MezonClient
• formData: Record of inputs (if embed has form)

👉 Details: Interaction → onClick.

4. Event-Driven with @On / @Once

Nezon re-exports all Nezon.Events from mezon-sdk.
@On listens continuously, @Once only runs the first time.

import { On, Once, AutoContext, SmartMessage } from "@n0xgg04/nezon";
import type { Nezon } from "@n0xgg04/nezon";

export class EventHandlers {
  @On(Nezon.Events.ChannelMessage)
  async logMessage(
    @AutoContext("message") message: Nezon.AutoContextType.Message
  ) {
    await message.reply(SmartMessage.text("Bot saw your message!"));
  }

  @Once(Nezon.Events.BotReady)
  onReady() {
    console.log("Bot ready!");
  }
}

• Supported decorators inside @On/@Once handlers:

  • @ChannelMessagePayload() / @EventPayload() – access raw payload from Mezon
  • @MessageContent() – read text content of the message (when the event is ChannelMessage)
  • @Channel() / @Channel('name') – get channel entity or a specific field
  • @Clan() – get clan entity
  • @User() / @User('username') – get user entity or a specific field
  • @Attachments() / @Mentions() – read files and mentions from payload
  • @Client() – get the current MezonClient instance
  • @AutoContext() – currently only supports the DM helper in event context ([null, dmHelper, null])
  • @NezonUtils() – inject NezonUtilsService for helpers (getClan, getChannel, etc.)

• Event list: Events List

• Detailed guide: Interaction → Events

4.1 @OnMention – when the bot is mentioned

@OnMention() is a shortcut for listening specifically to when the bot is mentioned in a channel:

• The source event is Nezon.Events.ChannelMessage
• Nezon automatically checks if message.mentions contains user_id === botId (taken from NezonModule.forRoot({ botId }))
• Only when the bot is mentioned will the @OnMention() handler be executed

import {
  OnMention,
  MessageContent,
  Channel,
  User,
  AutoContext,
} from "@n0xgg04/nezon";
import type { Nezon } from "@n0xgg04/nezon";

export class MentionHandlers {
  @OnMention()
  async onBotMention(
    @MessageContent() content: string,
    @Channel() channel: Nezon.Channel | undefined,
    @User() user: Nezon.User | undefined,
    @AutoContext("dm") dm: Nezon.AutoContextType.DM
  ) {
    if (!user) return;
    await dm.send(
      user.id,
      Nezon.SmartMessage.text(
        `You mentioned the bot in channel ${
          channel?.name ?? "unknown"
        } with content: ${content}`
      )
    );
  }
}

Note: @OnMention() shares the same parameter decorator system as @On() / @Once(), so you can also mix in @Mentions(), @Attachments(), @Client(), @NezonUtils(), ...

5. Quick Comparison

Need	Suggestion
User types command *	@Command
User clicks button/dropdown	@Component or ButtonBuilder.onClick
Handle form embed	@FormData (component/onClick)
Listen to system (join/leave/token)	@On, @Once with Nezon.Events.*

After handling logic, move to:

• Message Builder to build response content.
• Sending Messages to learn how to reply, DM, send to other channels, or use raw Mezon SDK.