Porting

You can port the boilerplate app from Figure 2 to other desktop systems using the forge package command. Without specifying options, the command (under Ubuntu 16.04) creates a standalone version for Linux and the existing x64 processor architecture in the out/app-linux-x64 subdirectory of the app project folder. In addition to the approximately 80MB executable app in ELF format, this directory also contains other binary files. You will find the web application and the required node packages under resources/app. After switching to the directory, the ./app command starts the app in the shell, which looks exactly like Figure 2.

You can port the app to Windows using the --platform command-line switch in the forge package --platform win32 command. This command creates the app for 64-bit Windows in the out/app-win32-x64 folder. In addition to the executable app.exe, the distribution contains a large number of Windows DLLs and the resources folder, which is more or less bit-identical to the matching folder for Linux.

If you copy the folder from Linux to a Windows 10 system and start the app, you won't see any notable differences with Figure 2. Conversely, you could install electron-forge under Windows 10, and, in that case, the Linux app created under Windows will run under Linux.

You can assign a processor architecture with the arch command-line switch. Table 1 shows the possible combinations of values for platform and arch.

Packing

forge offers to create platform-specific package formats or installers to facilitate easy distribution of the app (Table 2). forge make generates a Debian package for the Boilerplate app. However, the script terminated in our lab while trying to create an RPM package, with the error message from Figure 3. sudo apt-get install rpm fixed the problem.

Figure 3: Starting rpmbuild as a separate process using spawn failed at first because rpm was not yet installed.

Similar scenes occurred while trying to create a Windows installer with the forge make --platform win32 command. In this case, .NET support was missing:

sudo apt-get install mono wine

Under out/make/squirell.Windows/x64, you will find the app-1.0.0 Setup.exe installer file, which we were able to install on Windows 10 without any problems.

Listing 3 displays the configuration object [11] from the package.json file as a portal. Lines 2 to 13 contain the package formats to be generated in the make_targets sub-object, listed by operating system.

01 [...]
02 "forge": {
03  "make_targets": {
04   "win32": [
05    "squirrel"
06   ],
07   "darwin": [
08    "zip"
09   ],
10   "linux": [
11    "deb",
12    "rpm"
13   ]
14  },
15  "electronPackagerConfig": {
16   "packageManager": "yarn"
17  },
18  "electronWinstallerConfig": {
19   "name": "app"
20  },
21  "electronInstallerDebian": {},
22  "electronInstallerRedhat": {},
23  "github_repository": {
24   "owner": "",
25   "name": ""
26  },
27  "windowsStoreConfig": {
28   "packageName": "",
29   "name": "app"
30  }
31 }
32 [...]

Conclusions

Electron makes it easy to create desktop apps using popular web technologies such as HTML, CSS, and JavaScript. At the same time, Electron offers an infrastructure that can port apps to other systems via the command line.

Compared to Cordova Phone Gap [12], the installation is trivial, even if support for mobile operating systems such as Android or iOS is currently missing. If you want to be on the safe side, simply pack on the target system each time and test the app immediately.