How to access json file data from js file

Question

I'm developing a discord bot and i wanted to send a random sentence from my dactylo.json file when the user sends a specific message. However, when trying to access data from this file, I get an "undefined" error like it couldn't read my json file. I looked over many previous questions but couldn't find an answer that helped me, even though it helped other people. I'm sure I'm missing something but I can't seem to find what...

Here's my code from dactylo.json :

{
    "sentences":[
        {
            "sentence": "Un dragon gradé dégrade un gradé dragon.",
            "top":"0",
            "player":"Personne"
        },
        {
            "sentence":"Le mur murant Paris rend Paris murmurant.",
            "top":"0",
            "player":"Personne"
        },
        {
            "sentence":"Le cricri de la crique crie son cri cru et critique car il craint que l'escroc ne le croque et ne le craque.",
            "top":"0",
            "player":"Personne"
        }
    ]
}

And my code from dactylo.js where I try to get data :

const fs = require('fs');

module.exports = {
    name: 'dactylo',
    description: 'Démarre une partie de dactylo',
    execute(message) {
        message.reply("Recopiez la phrase suivante le plus rapidement possible :")
        const data = fs.readFileSync('C:/Users/steph/Documents/Discord Bot/commands/fun/dactylo.json');

        const sentences = data.sentences;
        var sentence = sentences[Math.floor(Math.random() * sentences.length)];
        message.channel.send(sentence);
    },
};

And the error I get in case it helps :

TypeError: Cannot read property 'length' of undefined
    at Object.execute (C:\Users\steph\Documents\Discord Bot\commands\fun\dactylo.js:11:71)
    at Client.<anonymous> (C:\Users\steph\Documents\Discord Bot\main.js:42:11)
    at Client.emit (events.js:375:28)
    at MessageCreateAction.handle (C:\Users\steph\Documents\Discord Bot\node_modules\discord.js\src\client\actions\MessageCreate.js:31:14)
    at Object.module.exports [as MESSAGE_CREATE] (C:\Users\steph\Documents\Discord Bot\node_modules\discord.js\src\client\websocket\handlers\MESSAGE_CREATE.js:4:32)
    at WebSocketManager.handlePacket (C:\Users\steph\Documents\Discord Bot\node_modules\discord.js\src\client\websocket\WebSocketManager.js:384:31)
    at WebSocketShard.onPacket (C:\Users\steph\Documents\Discord Bot\node_modules\discord.js\src\client\websocket\WebSocketShard.js:444:22)
    at WebSocketShard.onMessage (C:\Users\steph\Documents\Discord Bot\node_modules\discord.js\src\client\websocket\WebSocketShard.js:301:10)
    at WebSocket.onMessage (C:\Users\steph\Documents\Discord Bot\node_modules\ws\lib\event-target.js:132:16)
    at WebSocket.emit (events.js:375:28)

Please refer [is there a require for json in node.js](https://stackoverflow.com/questions/7163061/is-there-a-require-for-json-in-node-js) — sainath chorghe, Jul 06 '21 at 14:49

hp10 · Accepted Answer · 2021-07-06T15:03:48.140

1

You can simply import json file on the beginning:

const dactylo = require('<path_to_json>.json');

edited Jul 06 '21 at 15:03

answered Jul 06 '21 at 14:47

hp10

602
6
11

score 0 · Answer 2 · answered Jul 06 '21 at 14:50

0

You can use require to automatically parse JSON for you

const data = require('path/to/file.json');

Also, it's better practice to use a relative path to the file instead of an absolute.

answered Jul 06 '21 at 14:50

mikach

2,427
2
14
15

score 0 · Answer 3 · answered Jul 06 '21 at 14:59

In your case, the fs.readFileSync function returns a Buffer, not the parsed json content as you expect.

In order to obtain the parsed JSON content, you need to follow two steps:

Read the .json file content as text
Parse the text with JSON.parse

The following code illustrates how it works:

const jsonPath = 'C:/Users/steph/Documents/Discord Bot/commands/fun/dactylo.json';
const jsonText = fs.readFileSync(jsonPath, "utf8"); 
const jsonObject = JSON.parse(jsonText);
console.log(jsonObject.sentences.length);   // 3

Notice that the second parameter passed to the fs.readFileSync function tells the function to return the file content as String and not as Buffer.

How to access json file data from js file

3 Answers3