I'm making a text hosting service and I want it to say "TextMessage Not found! You can create one in the name by clicking here" but I don't know how to do that. I tried making a custom 404 error, and detecting if the file exists via the node fs module, that did not work out.

this is my code:

// Importing require packages/modules  
const express = require("express");  
const bodyParser = require("body-parser");  
const fs = require("fs");  
// Defining needed variables  
const app = express();  
const PORT = 3000;  
// Express midleware to enable body-parser  
app.use(bodyParser.urlencoded({ extended: false }));  
// Express static handler  
app.use(express.static("public"));  
// POST API To create message/file  
app.post("/api/message/submit", (req, res) => {  
  const file = req.body.messageText;  
  const fileID = req.body.messageID;  
  fs.writeFile(__dirname   "/messageFiles/"   fileID   ".txt",  
 file, (err) => {  
    if (err) res.send("ERROR! <br>"   err);  
    else res.send("Saved");  
  });  
});  
// GET API To read message/file        
app.get("/message/:id", (req, res) => {     
  const msg = req.params.id;    
  if (fs.existsSync(__dirname   "/messageFile/"   msg   ".txt")) {   
    res.sendFile(__dirname   "/messageFiles/"   msg   ".txt");   
  } else {    
    res.send("Message does not exist");    
  }   
});   
// Running the server  
app.listen(PORT, () => {  
  console.log("Running on port: "   PORT);  
});    

`

CodePudding user response：

You may try async writing to a file by wrapping it with trycatch block. It seems you have a problem with path to the file.

I suggest you to have a helper functions to write to a file and read from a file:

const create = async (data, fileName) => {
    try {
        const text = await fs.writeFile(`./files/${fileName}.txt`, data);
        console.log('File write successful!');
    } catch (error) {
        throw new Error('File write operation failed');
    }
};

const read = async (fileName) => {
    try {
        const fileContent = await fs.readFile(`./files/${fileName}.txt`, {encoding: 'utf-8'});
        return fileContent;
    } catch (error) {
        throw new Error('File read operation failed');
    }
};

app.post("/api/message/submit", async (req, res) => {  
  const fileContent = req.body.messageText;  
  const fileID = req.body.messageID;  
  const message = await create(fileContent, fileID);
  message ? res.send('Successful') : res.send('Failed');
});

app.get("/message/:id", async (req, res) => {     
  const msgID = req.params.id;    
  const message = await read(msgID);
  res.send(message);
});  

I hope it helps!

P.S.: Don't use too many comments. Your code should be self-documenting (readable)!

P.S.S: Added async keyword before (req, res).