Electron function to read a local file - FS - Not reading

Question

I have an electron project when I need to get electron to read a local file.

Right now what I have is this, where it loads and displays the contents of a html file.

I just need it to read a file and store it on a variable for now.

Here is my current main.js:

 const {app, BrowserWindow } = require('electron');
const path = require('path');
const url = require('url');
var fs = require('fs');

let mainWindow;

function createNewWindow() {
  mainWindow = new BrowserWindow({
    width: 1300,
    height: 1000,
    minWidth: 600,
    minHeight: 400,
    title: 'Test App'
  })
}

function loadInitialUrl() {
  mainWindow.loadURL(url.format({
    pathname: path.join(__dirname, 'index.html'),
    protocol: 'file:',
    slashes: true
  }))
}

function closeApplication() {
  mainWindow.on('closed', () => {
    mainWindow = null;
})
}


app.on('ready', function(){
  createNewWindow();
  loadInitialUrl();
  mainWindow.setMenu(null);
  mainWindow.openDevTools();
  fs.readFile('./README.md', 'utf8', function (err,data) {
    if (err) {
      return console.log(err);
    }
    console.log(data);
  });
  mainWindow.on('closed', function() {mainWindow = null;});
});

How can I do this as it's not showing the contents of the README.md file in the console.log

possible duplicate of [Open external file with Electron](http://stackoverflow.com/questions/30381450/open-external-file-with-electron) — Ja9ad335h, May 01 '17 at 16:23
make sure the `path` is correct. what is the current output of log? — Rohith K P, May 01 '17 at 17:30

Rohith K P · Accepted Answer · 2017-05-01T17:34:43.020

Basically you need to do the following things.

1.Loading required dependencies

var remote = require('remote'); // Load remote compnent that contains the dialog dependency
var dialog = remote.require('dialog'); // Load the dialogs component of the OS
var fs = require('fs'); // Load the File System to execute our common tasks (CRUD)

2.Read file content

dialog.showOpenDialog((fileNames) => {
    // fileNames is an array that contains all the selected
    if(fileNames === undefined){
        console.log("No file selected");
        return;
    }

    fs.readFile(filepath, 'utf-8', (err, data) => {
        if(err){
            alert("An error ocurred reading the file :" + err.message);
            return;
        }

        // Change how to handle the file content
        console.log("The file content is : " + data);
    });
});

3.Update existing file content

 var filepath = "C:/Previous-filepath/existinfile.txt";// you need to save the filepath when you open the file to update without use the filechooser dialog againg
var content = "This is the new content of the file";

fs.writeFile(filepath, content, (err) => {
    if (err) {
        alert("An error ocurred updating the file" + err.message);
        console.log(err);
        return;
    }

    alert("The file has been succesfully saved");
});

For more read please visit here :) Thanks..

One more thing to add..Please check that your path to file is correct. You could do something similar to below.

var path = require('path');
var p = path.join(__dirname, '.', 'README.md');

I'm not looking for a file dialog...just to read the contents of a local file and maybe show in the console.log — , May 01 '17 at 17:07
@JakeBrown777 if you just want to read file..and you know the file path then `fs.readFile(filepath,..` will do — Rohith K P, May 01 '17 at 17:26
In 2. Read the file with dialog, how can I obtain the file path to do fs.weriteFile(filepath,..)? — Anand, Aug 17 '18 at 07:02
Hi @Anand, I think `fileNames` parameter passed to showOpenDialog's callback contains the filepath. You can access it like `var filepath = fileNames[0]` — Rohith K P, Aug 17 '18 at 12:39
Also see this reference=> https://www.tutorialspoint.com/electron/electron_system_dialogs.htm — Rohith K P, Aug 17 '18 at 12:39

score 7 · Answer 2 · edited Jul 23 '22 at 00:27

7

Just one update information for the accepted answer. After the update of electron, you can directly use

const { dialog } = require('electron');

to import dialog.

And for remote, if you need to use it, you also need:

const { remote } = require('electron');

https://www.electronjs.org/docs/latest/api/dialog/

edited Jul 23 '22 at 00:27

atlas_scoffed

3,542
30
46

answered Jul 23 '19 at 00:04

zhuzilin

307
4
8

Electron function to read a local file - FS - Not reading

2 Answers2

Linked