Reactions and how they work

What are reactions?

Whenever a message is sent in Discord, users can add "reactions" to the message. These can be anything from a heart, the poop emoji, or any of the custom ones you can put on servers. It looks like this:

Reactions

How do I add them?

Well users can manually add them by right clicking on a message or hitting the little face next to the message when they hover over it. But a bot needs to add them a little differently. To add an reaction there's a few ways to do it. You can either use the unicode version, or ReactionEmoji.

Reaction Emoji

ReactionEmoji is a class made to make reactions easier. To get a ReactionEmoji you can use any of the three ReactionEmoji#of methods. You can react to any message with IMessage#react(ReactionEmoji)

  • ReactionEmoji.of(IEmoji) This is for if you have a custom emoji and want to react with it (IEmoji are emojis that are guild specific).

  • ReactionEmoji.of(String) This one is for the unicode of an emoji. (For instance, is the unicode for :heart:. This can be gotten on any non-custom emoji as \:emoji:, in this case \:heart:. You need to type this into your chat in Discord.)

  • ReactionEmoji.of(String, long) This is for custom emojis from other servers. Since bots can do that now. I took the :eyesR: emoji from one of the servers my bot is in and used it for this. To get the name (String) and the ID (long), this is the same as above except for custom emojis you'll get the name and ID instead of the unicode, so in my case \:eyesR:. This gives me <:eyesR:284174731261902850>. It'll be different for every server. Using the following code I can achieve the following image:

eyesR

Code:

        ReactionEmoji reaction = ReactionEmoji.of("eyesR", 284174731261902850L);
        message.addReaction(reaction);

Emoji Manager

EmojiManager, from the Emoji-Java library, can be used to get an emoji by its shortcode. It returns an Emoji object which can be directly used in IMessage#addReaction() instead of ReactionEmoji. This should only be used when you have to get a unicode emoji by its name. All other forms are supported through ReactionEmoji and are much cleaner. For the same result as above just, just do this:

Code:

Emoji e = EmojiManager.getForAlias("heart");
message.addReaction(e);

Remember to not use colons when grabbing it by alias. Unfortunatley EmojiJava doesn't support all emojis, such as :track_next:, and you can find the unicode online or by using the method explained in the section above.