Handling Updates

What is an Update?

An update is an event sent by Telegram to your bot — for example, a new message, a button press, a poll answer, or a payment event.
In Telebof, you handle updates by using handler method or annotation (Recommended).

In this section, we will learn how we can handle updates by using handler methods

Each handler method:

• Accepts a filter to determine which updates it should process.
• Accepts a callback that is executed when the filter matches.

Filter
The filter is a lambda of type io.github.natanimn.telebof.filter.FilterExecutor, which takes a io.github.natanimn.telebof.filter.Filter object and returns a Boolean.
If the filter condition matches the incoming update, the callback is triggered.

Callback
The callback is a function that takes two parameters:

1. io.github.natanimn.telebof.BotContext – allows sending messages, editing content, etc.
2. The specific update type being handled.

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Example: Basic Echo Bot

Let’s revisit our first echo bot:

import io.github.natanimn.telebof.BotClient;

public class MyFirstBot {
  static final String TOKEN = "YOUR_BOT_TOKEN_HERE";

  public static void main(String[] args) {
    final BotClient bot = new BotClient(TOKEN);

    // Responding to /start command
    bot.onMessage(filter -> filter.commands("start"), (context, message) -> {
        context.sendMessage(message.chat.id, "Welcome!").exec();
    });

    // Echoing any incoming text
    bot.onMessage(filter -> filter.text(), (context, message) -> {
        context.sendMessage(message.chat.id, message.text).exec();
    });

    bot.startPolling(); // Start the bot
  }
}

In this example:

• First handler: Responds to /start with “Welcome!”.
• Second handler: Echoes any text sent to the bot.
• sendMessage sends a message.

• exec() executes the request to Telegram.

• Optional parameters (e.g., parse_mode, reply_markup) can be set before calling exec().

Example with Markdown parse mode:

import enums.
io.github.natanimn.telebof.ParseMode;

context.sendMessage(message.chat.id, "*Hello, World*")
       .parseMode(ParseMode.MARKDOWN)
       .exec();

- startPolling() Starts the bot using long polling, continuously fetching updates from Telegram.

Important: Handlers are executed in the order they are registered. If multiple handlers match the same update, earlier ones run first.

Types of Handlers

Telegram bots can receive a variety of updates, each representing a different type of event.
Telebof provides 22 handler methods to process these updates easily.

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All Update Types in Telebof

Update Type	Handler Method	Description
Message	bot.onMessage	Handles incoming messages from users or groups.
Callback Query	bot.onCallback	Handles button presses from inline keyboards.
Inline Query	bot.onInline	Handles inline queries typed in other chats.
Poll	bot.onPoll	Handles new polls.
Poll Answer	bot.onPollAnswer	Handles answers to polls.
Shipping Query	bot.onShipping	Handles shipping related queries for payments.
Channel Post	bot.onChannelPost	Handles new channel posts.
Pre-Checkout Query	bot.onPreCheckout	Handles payment pre-checkout events.
Edited Message	bot.onEditedMessage	Handles edits to existing messages.
Edited Channel Post	bot.onEditedChannelPost	Handles edits to channel posts.
My Chat Member	bot.onMyChatMember	Handles changes to the bot's role in a chat.
Chat Member	bot.onChatMember	Handles changes to a user's role in a chat.
Chosen Inline Result	bot.onChosenInlineResult	Handles the result chosen from an inline query.
Message Reaction	bot.onReaction	Handles when someone reacts to a message.
Message Reaction Count	bot.onReactionCount	Handles updates to reaction counts.
Chat Boost	bot.onChatBoost	Handles when a chat is boosted.
Removed Chat Boost	bot.onRemovedChatBoost	Handles when a boost is removed from a chat.
Business Message	bot.onBusinessMessage	Handles new business messages.
Business Connection	bot.onBusinessConnection	Handles new or updated business connections.
Edited Business Message	bot.onEditedBusinessMessage	Handles edits to business messages.
Deleted Business Message	bot.onDeletedBusinessMessage	Handles deletions of business messages.

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Usages

1. Handling Different Message Types

// Handle text messages
bot.onMessage(filter -> filter.text(), (context, message) -> {
    context.sendMessage(message.chat.id, "You said: " + message.text).exec();
});

// Handle photo messages
bot.onMessage(filter -> filter.photo(), (context, message) -> {
    context.sendMessage(message.chat.id, "Nice photo!").exec();
});

// Handle document messages
bot.onMessage(filter -> filter.document(), (context, message) -> {
    context.sendMessage(message.chat.id, "File received").exec();
});

2. Handling Callback Queries from Inline Keyboards

bot.onCallback(filter -> filter.calbackData("button_1"), (context, callback) -> {
    context.answerCallbackQuery(callback.id, "Button 1 pressed!").exec();

    context.editMessageText("You pressed Button 1", 
                           callback.message.chat.id, 
                           callback.message.message_id).exec();
});

3. Handling Inline Queries

bot.onInline(filter -> true, (context, inline) -> {
    var result = new InlineQueryResultArticle("1", "Title", 
                     new InputTextMessageContent("Hello from inline!"));
    context.answerInlineQuery(inline.id, new InlineQueryResult[]{result}).exec();
});