Dynamic Slash Command Options List via Database Query? - node.js

Question

Background:
I am building a discord bot that operates as a Dungeons & Dragons DM of sorts. We want to store game data in a database and during the execution of certain commands, query data from said database for use in the game.
All of the connections between our Discord server, our VPS, and the VPS' backend are functional and we are now implementing slash commands since traditional ! commands are being removed from support in April.
We are running into problems making the slash commands though. We want to set them up to be as efficient as possible which means no hard-coded choices for options. We want to build those choice lists via data from the database.
The problem we are running into is that we can't figure out the proper way to implement the fetch to the database within the SlashCommandBuilder.
Here is what we currently have:
const {SlashCommandBuilder} = require('#discordjs/builders');
const fetch = require('node-fetch');
const {REST} = require('#discordjs/rest');
const test = require('../commonFunctions/test.js');
var options = async function getOptions(){
let x = await test.getClasses();
console.log(x);
return ['test','test2'];
}
module.exports = {
data: new SlashCommandBuilder()
.setName('get-test-data')
.setDescription('Return Class and Race data from database')
.addStringOption(option =>{
option.setName('class')
.setDescription('Select a class for your character')
.setRequired(true)
for(let op of options()){
//option.addChoice(op,op);
}
return option
}
),
async execute(interaction){
},
};
This code produces the following error when start the npm for our bot on our server:
options is not a function or its return value is not iterable
I thought that maybe the function wasn't properly defined, so I replaced the contents of it with just a simple array return and the npm started without errors and the values I had passed showed up in the server.
This leads me to think that the function call in the modules.exports block is immediatly attempting to get the return value of the function and as the function is async, it isn't yet ready and is either returning undefined or a promise or something else not iteratable.
Is there a proper way to implement the code as shown? Or is this way too complex for discord.js to handle?
Is there a proper way to implement the idea at all? Like creating a json object that contains the option data which is built and saved to a file at some point prior to this command being registered and then having the code above just pull in that file for the option choices?

Answer 1

Alright, I found a way. Ian Malcom would be proud (LMAO).
Here is what I had to do for those with a similar issues:
I had to basically re-write our entire application. It sucks, I know, but it works so who cares?
When you run your index file for your npm, make sure that you do the following things.
Note: you can structure this however you want, this is just how I set up my js files.
Setup a function that will setup the data you need, it needs to be an async function as does everything downstream from this point on relating to the creation and registration of the slash commands.
Create a js file to act as your application setup "module". "Module" because we're faking a real module by just using the module.exports method. No package.jsons needed.
In the setup file, you will need two requires. The first is a, as of yet, non-existent data manager file; we'll do that next. The second is a require for node:fs.
Create an async function in your setup file called setup and add it to your module.exports like so:
module.exports = { setup }
In your async setup function or in a function that it calls, make a call to the function in your still as of yet non-existent data manager file. Use await so that the application doesn't proceed until something is returned. Here is what mine looks like, note that I am writing my data to a file to read in later because of my use case, you may or may not have to do the same for yours:
async function setup(){
console.log('test');
//build option choice lists
let listsBuilt = await buildChoiceLists();
if (listsBuilt){
return true;
} else {
return false;
}
}
async function buildChoiceLists(){
let classListBuilt = await buildClassList();
return true;
}
async function buildClassList(){
let classData = await classDataManager.getClassData();
console.log(classData);
classList = classData;
await writeFiles();
return true;
}
async function writeFiles(){
fs.writeFileSync('./CommandData/classList.json', JSON.stringify(classList));
}
Before we finish off this file, if you want to store anything as a property in this file and then get it later on, you can do so. In order for the data to return properly though, you will need to define a getter function in your exports. Here is an example:
var classList;
module.exports={
getClassList: () => classList,
setup
};
So, with everything above you should have something that looks like this:
const classDataManager = require('./DataManagers/ClassData.js')
const fs = require('node:fs');
var classList;
async function setup(){
console.log('test');
//build option choice lists
let listsBuilt = await buildChoiceLists();
if (listsBuilt){
return true;
} else {
return false;
}
}
async function buildChoiceLists(){
let classListBuilt = await buildClassList();
return true;
}
async function buildClassList(){
let classData = await classDataManager.getClassData();
console.log(classData);
classList = classData;
await writeFiles();
return true;
}
async function writeFiles(){
fs.writeFileSync('./CommandData/classList.json', JSON.stringify(classList));
}
module.exports={
getClassList: () => classList,
setup
};
Next that pesky non-existent DataManager file. For mine, each data type will have its own, but you might want to just combine them all into a single .js file for yours.
Same with the folder name, I called mine DataManagers, if you're combining them all into one, you could just call the file DataManager and leave it in the same folder as your appSetup.js file.
For the data manager file all we really need is a function to get our data and then return it in the format we want it to be in. I am using node-fetch. If you are using some other module for data requests, write your code as needed.
Instead of explaining everything, here is the contents of my file, not much has to be explained here:
const fetch = require('node-fetch');
async function getClassData(){
return new Promise((resolve) => {
let data = "action=GetTestData";
fetch('http://xxx.xxx.xxx.xx/backend/characterHandler.php', {
method: 'post',
headers: { 'Content-Type':'application/x-www-form-urlencoded'},
body: data
}).then(response => {
response.json().then(res => {
let status = res.status;
let clsData = res.classes;
let rcData = res.races;
if (status == "Success"){
let text = '';
let classes = [];
let races = [];
if (Object.keys(clsData).length > 0){
for (let key of Object.keys(clsData)){
let cls = clsData[key];
classes.push({
"name": key,
"code": key.toLowerCase()
});
}
}
if (Object.keys(rcData).length > 0){
for (let key of Object.keys(rcData)){
let rc = rcData[key];
races.push({
"name": key,
"desc": rc.Desc
});
}
}
resolve(classes);
}
});
});
});
}
module.exports = {
getClassData
};
This file contacts our backend php and requests data from it. It queries the data then returns it. Then we format it into an JSON structure for use later on with option choices for the slash command.
Once all of your appSetup and data manager files are complete, we still need to create the commands and register them with the server. So, in your index file add something similar to the following:
async function getCommands(){
let cmds = await comCreator.appSetup();
console.log(cmds);
client.commands = cmds;
}
getCommands();
This should go at or near the top of your index.js file. Note that comCreator refers to a file we haven't created yet; you can name this require const whatever you wish. That's it for this file.
Now, the "comCreator" file. I named mine deploy-commands.js, but you can name it whatever. Once again, here is the full file contents. I will explain anything that needs to be explained after:
const {Collection} = require('discord.js');
const {REST} = require('#discordjs/rest');
const {Routes} = require('discord-api-types/v9');
const app = require('./appSetup.js');
const fs = require('node:fs');
const config = require('./config.json');
async function appSetup(){
console.log('test2');
let setupDone = await app.setup();
console.log(setupDone);
console.log(app.getClassList());
return new Promise((resolve) => {
const cmds = [];
const cmdFiles = fs.readdirSync('./commands').filter(f => f.endsWith('.js'));
for (let file of cmdFiles){
let cmd = require('./commands/' + file);
console.log(file + ' added to commands!');
cmds.push(cmd.data.toJSON());
}
const rest = new REST({version: '9'}).setToken(config.token);
rest.put(Routes.applicationGuildCommands(config.clientId, config.guildId), {body: cmds})
.then(() => console.log('Successfully registered application commands.'))
.catch(console.error);
let commands = new Collection();
for (let file of cmdFiles){
let cmd = require('./commands/' + file);
commands.set(cmd.data.name, cmd);
}
resolve(commands);
});
}
module.exports = {
appSetup
};
Most of this is boiler plate for slash command creation though I did combine the creation and registering of the commands into the same process. As you can see, we are grabbing our command files, processing them into a collection, registering that collection, and then resolving the promise with that variable.
You might have noticed that property, was used to then set the client commands in the index.js file.
Config just contains your connection details for your discord server app.
Finally, how I accessed the data we wrote for the SlashCommandBuilder:
data: new SlashCommandBuilder()
.setName('get-test-data')
.setDescription('Return Class and Race data from database')
.addStringOption(option =>{
option.setName('class')
.setDescription('Select a class for your character')
.setRequired(true)
let ops = [];
let data = fs.readFileSync('./CommandData/classList.json','utf-8');
ops = JSON.parse(data);
console.log('test data class options: ' + ops);
for(let op of ops){
option.addChoice(op.name,op.code);
}
return option
}
),
Hopefully this helps someone in the future!