Messages

Message objects provide useful methods and events to make your life easier.

Methods

Messages have four methods:

reply

As you've probably already seen in the examples, this method sends a reply to a message. Slack doesn't have real replys as Telegram does, so this method just sends a message to the same channel as the message.

bot.listen(/Turn on coffee machine/i, message => {
  message.reply('Consider it done!');

  // equivalent:
  // bot.sendMessage(message.channel, 'Consider it done!');
});

update

This method updates the message, it's a shortcut for bot.updateMessage.

bot.command('count from <number>', async message => {
  let [num] = message.match;
  num = parseInt(num, 10);
  const msg = await message.reply(num);

  setInterval(() => {
    msg.update(--n);

    // equivalent:
    // bot.updateMessage(msg.channel, msg.ts, --n);
  }, 1000);
});

delete

This method deletes the message, it's a shortcut for bot.deleteMessage.

const msg = await bot.sendMessage('something wrong!');
msg.delete();

// equivalent:
// bot.deleteMessage(msg.channel, msg.ts);

react

This method adds a reaction to a message, it's a shortcut for bot.react.

bot.hear(/Thank you/i, message => {
  message.react(':pray:');

  // equivalent:
  // bot.react(message.channel, message.ts, ':pray:');
});

For more information on methods, see Methods.

Events

The events received from Slack API server are not as easy to use, because you'll have to match the received event's message id with your message, so we do that for you.

You can use on and off methods of messages to set listeners on events.

update

Triggers when a user updates their message.

bot.hear(message => {
  message.on('update', () => {
    message.reply('You changed your mind?');
  });
});

delete

Triggers when a message is deleted.

bot.hear(message => {
  message.on('delete', () => {
    message.reply('Oooo, looks like someone\'s hiding something');
  });
});

reaction_added

Triggers when someone adds a reaction to a message.

const msg = await bot.sendMessage('Who wants me to dance?');
const votes = 0;
msg.on('reaction_added', event => {
  if (event.reaction === 'thumbsup') votes++;
  votes--;
});

reaction_removed

Triggers when someone removes their reaction from a message.

const msg = await bot.sendMessage('Who wants me to dance?');
const votes = 0;
msg.on('reaction_added', event => {
  if (event.reaction === 'thumbsup') votes++;
  votes--;
});

msg.on('reaction_removed', event => {
  if (event.reaction === 'thumbsup') votes--;
  votes++;
});

For more information on the events, see Events.