index.js

'use strict';

/* eslint no-path-concat: 0, func-names:0 */

// Imports
const electron = require('electron');
const {app} = electron;
const {BrowserWindow} = electron;

var util = require('util');
var colors = require('colors');
var EventEmitter = require('events');
var spawn = require('child-process-promise').spawn;

var DEFAULT_WINDOW = { width: 1024, height: 728, show: false };
var NOOP = function(){};
var DEBUG = function(text) {
  var time = new Date().toLocaleTimeString();
  console.log('['.grey + time.green + ']'.grey + colors.reset(' ' + text));
};

function electronify(cfg) {
  var self = this;

  // Initialize necessary properties from `EventEmitter` in this instance
  EventEmitter.call(self);

  // setup debug logger
  var debug = NOOP;
  if (cfg.debug) {
    debug = DEBUG;
  }

  app.on('window-all-closed', function() {
    debug('All windows closed.');

    // quit after last window is closed
    app.quit();
  });

  app.on('ready', function() {
    debug('App ready.');
    if (cfg.ready) cfg.ready(app);

    // The app will start with no command if the noServer option is true.
    if (cfg.noServer) {
      start(cfg, app, null, debug);
      return

    // The app will quit if there is no command to run.
    } else if (!cfg.noServer && !cfg.command) {
      debug('No command configured!');
      self.emit('error', new Error('Empty command!'), app);
      return
    }

    // start child process
    var args = cfg.args? cfg.args : [];
    var opts = cfg.options? cfg.options: {};
    spawn(cfg.command, args, opts)
      .then(function (result) {
        debug('Command completed.');

        // Send output
        var stdout = result.stdout;
        var stderr = result.stderr;
        self.emit('child-closed', app, stderr, stdout);
      })
      .fail(function (err) {
        debug(err);
        self.emit('child-error', err, app);
        // app.quit();
      })
      .progress(function (childProcess) {
        debug('Command started. [PID: ' + childProcess.pid + ']');
        self.emit('child-started', childProcess);

        start(cfg, app, childProcess, debug);
      });
  });
}

// Inherit functions from `EventEmitter`'s prototype
util.inherits(electronify, EventEmitter);

module.exports = function(cfg) {
  return new electronify(cfg);
};

function start(cfg, app, childProcess, debug) {
  app.on('quit', function() {
    if(childProcess && !childProcess.killed) childProcess.kill();
  });

  // setup window config
  var browserConfig =  cfg.window || DEFAULT_WINDOW ;
  browserConfig.show = false;

  // create window
  var window = new BrowserWindow(browserConfig);

  // call pre load handler
  // menus could be created in this function
  // window and app event handlers could also be added here
  if (cfg.preLoad) cfg.preLoad(app, window);

  // health check to verify server started
  if (cfg.healthCheck) {
    cfg.healthCheck(app, window, function() {
      window.loadURL(cfg.url);
    })
  } else {
    // load url
    window.loadURL(cfg.url);
  }

  window.webContents.on('did-finish-load', function() {
    debug('Finished loading.');

    // call post load handler
    if (cfg.postLoad) cfg.postLoad(app, window);

    window.show();
  });

  window.webContents.on('did-fail-load', function(event, errorCode, errorDescription, validatedURL, isMainFrame) {
    debug('Loading failed.');

    var error = {
      event: event,
      errorCode: errorCode,
      errorDescription: errorDescription,
      validatedURL: validatedURL,
      isMainFrame: isMainFrame
    }

    if (cfg.postLoad) cfg.postLoad(app, window, error);
  });

  // Clean resource
  window.on('closed', function() {
    debug('Window closed.');
    window = null;
  });

  // Enable dev tools
  if (cfg.showDevTools) window.openDevTools();
}