Is there a way to react to every message ever sent with discord.js

Question

I wanna use an bot to react to every single message in an channel using discord.js f.e. i got an emoji contest channel and i wanna ad an ✅ and an ✖ reaction on every post in there ofc, all the unnecesary messages are cleaned up so that there are like 50 messages

score 3 · Accepted Answer · answered Jul 08 '19 at 15:32

3

Fetch the messages already sent in a channel with TextChannel.fetchMessages().
Iterate through the Collection.
Add reactions with Message.react().
When a new message is sent in the channel, you should also add the reactions.

const emojiChannelID = 'ChannelIDHere';

client.on('ready', async () => {
  try {
    const channel = client.channels.get(emojiChannelID);
    if (!channel) return console.error('Invalid ID or missing channel.');

    const messages = await channel.fetchMessages({ limit: 100 });

    for (const [id, message] of messages) {
      await message.react('✅');
      await message.react('✖');
    }
  } catch(err) {
    console.error(err);
  }
});

client.on('message', async message => {
  if (message.channel.id === emojiChannelID) {
    try {
      await message.react('✅');
      await message.react('✖');
    } catch(err) {
      console.error(err);
    }
  }
});

In this code, you'll notice I'm using a for...of loop rather than Map.forEach(). The reasoning behind this is that the latter will simply call the methods and move on. This would cause any rejected promises not to be caught. I've also used async/await style rather than then() chains which could easily get messy.

answered Jul 08 '19 at 15:32

slothiful

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got it working like that, thx, but im pretty new to js coding, what does this => i figure it doesnt mean sammerl or equal than – ScarVite Jul 08 '19 at 16:09
`=>` is actually part of the [arrow function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions) syntax. `<=` and `>=` are [relational operator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comparison_Operators#Relational_operators)s. `=>` and `>=` can be easily confused, but they're very different. – slothiful Jul 08 '19 at 16:12
can you develop on the rejected promises part? I used the `Map.forEach()` in one of my previous answer and didn't think/know about it. You're talking about the `message.react` promise, aren't you? Because if a promise if rejected, the `forEach` will stop so it will be stopped and go in the catch as you for, no? – JackRed Jul 09 '19 at 05:42
1

The way `forEach()` works, no. It simply invokes the Promise and continues to iterate. By the time it's done, Promises will be still be in their pending state. Even if you use the `await` keyword, it's not going to be effective towards this issue. See [here](https://stackoverflow.com/questions/37576685/using-async-await-with-a-foreach-loop/45006966) for a much more thorough explanation of the workings and the problem. – slothiful Jul 09 '19 at 11:37

Thomas Billot · Answer 2 · 2019-07-08T15:35:47.010

According to https://discord.js.org/#/docs/main/stable/class/TextChannel

you can use fetchMessages to get all messages from a specific channel, which then returns a collection of Message

Then you can use .react function to apply your reactions to this collection of message by iterating over it and calling .react on each.

Edit:

channelToFetch.fetchMessages()
    .then(messages => {
        messages.tap(message => {
            message.react(`CHARACTER CODE OR EMOJI CODE`).then(() => {
              // Do what ever or use async/await syntax if you don't care 
                 about Promise handling
            })
        })
    })

Is there a way to react to every message ever sent with discord.js

2 Answers2

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