User Permissions

In the last chapter we talked about how to check for bot permissions, in this chapter, we're going to be using a hasPermission method and the userPermissions option to check whether or not the user is the owner or has a certain permission before using the command.

The hasPermission method can be anything you want, as long as it returns true or false. When it returns true, the command will run. When it returns false, the user will not be allowed to use the command.

Doing this is quite simple.

hasPermission(msg) {
    return this.client.isOwner(msg.author);
}

This will return false if the user is not the owner of the bot and true if they are.

The hasPermission method should be placed separate from the run method, like so (if you wanted your say command to only be usable by the owner):

const { Command } = require('discord.js-commando');

module.exports = class SayCommand extends Command {
    constructor(client) {
        super(client, {
            name: 'say',
            aliases: ['copycat', 'repeat', 'echo', 'parrot'],
            group: 'group2',
            memberName: 'say',
            description: 'Replies with the text you provide.',
            examples: ['say Hi there!'],
            guildOnly: true,
            args: [
                {
                    key: 'text',
                    prompt: 'What text would you like the bot to say?',
                    type: 'string'
                }
            ]
        });    
    }

    hasPermission(msg) {
        return this.client.isOwner(msg.author);
    }

    run(msg, { text }) {
        msg.delete();
        return msg.say(text);
    }
};

Simple.

You can also return a string for a custom response.

hasPermission(msg) {
    if (!this.client.isOwner(msg.author)) return 'Only the bot owner(s) may use this command.';
    return true;
}

Neat, huh?

Another thing you might want to do is check for specific user permissions, such as if a user has permissions in the current channel to manage messages. We can do that even more simply with the userPermissions option.

super(client, {
    name: 'say',
    aliases: ['copycat', 'repeat', 'echo', 'parrot'],
    group: 'group2',
    memberName: 'say',
    description: 'Replies with the text you provide.',
    examples: ['say Hi there!'],
    userPermissions: ['MANAGE_MESSAGES'],
    args: [
        {
            key: 'text',
            prompt: 'What text would you like the bot to say?',
            type: 'string'
        }
    ]
});

Just like clientPermissions.