将主进程作为child_process运行

Question

I am having troubles with getting child_process working with Atom Electron. First of all, I am using the pre-compiled binary app that you can download from Electron's website:

• I am using the usual pre-compiled binary on Mac OS X.
• In myapp.app/Contents/Resources I made a folder app as described.
• I added a brief package.json inside it, setting index.js as main script.

Now, if I add to index.js the following snippet:

'use strict';

var electron = require('electron');
var app = electron.app;

const BrowserWindow = electron.BrowserWindow;

var mainWindow;

function createWindow () {
  mainWindow = new BrowserWindow({width: 800, height: 600});
  mainWindow.loadURL('file://' + __dirname + '/index.html');
  mainWindow.webContents.openDevTools();
  mainWindow.on('closed', function()
  {
    mainWindow = null;
  });
}

app.on('ready', createWindow);

app.on('window-all-closed', function () {
  if (process.platform !== 'darwin')
  {
    app.quit();
  }
});

app.on('activate', function () {
  if (mainWindow === null)
  {
    createWindow();
  }
});

(that is basically the example code to get things working) everything works fine. I get the window and I can get it to do basically anything.

Now, for reasons related to updates, I am in need to slightly change this paradigm. What I would need is to be able to perform several tasks from index.js without any need to do any gui operation (it should be some sort of daemon) and then to start some child.js script as a child_process from index.js . child.js should be able to open windows and all the rest.

So here was my naive try. I just cut and pasted the example snippet above in child.js , then edited index.js into the following:

var child_process = require('child_process');
var my_child = child_process.fork(__dirname + '/child.js');

Quite minimal, right? Hoped it would work, but it didn't. When I double click on my pretty app, nothing happens. I bet I am doing something wrong in a trivial way, but I wouldn't be able to tell what.

Update 1 I moved this out of my package so that I could get console.log s. child.js dies with an error at require('electron') : it doesn't seem to be able to find it.

Update 2 : I listed the environment variables in child.js and noticed a ATOM_SHELL_INTERNAL_RUN_AS_NODE = 1 . I thought I should turn that to 0 , but nothing changed.

Answer 1

In Electron child_process.fork() will spawn the child with the ATOM_SHELL_INTERNAL_RUN_AS_NODE environment variable set, which means that no Chromium features will be available in the child process (so no Electron built-in modules), all you'll get is the vanilla Node runtime plus a patched fs that can read inside ASAR files. If you look at the code for child_process.fork() you'll see there's no way to override the value of ATOM_SHELL_INTERNAL_RUN_AS_NODE . If you can, use child_process.spawn() instead, failing that I guess you could try opening an issue and asking if the Electron team will be open to modifying the current behavior.