Capacitor is an open source native runtime for building cross-platform mobile and Progressive Web Apps, with JavaScript, HTML, and CSS.
For this first we will need a nuxt.js application where we will integrate our capacitor. Nuxt.js can be seen from the docs here.

Capacitor allows to build our app with modern web components that is cross-platform that is Android, iOS, PWA and electron.

Lets start with adding Capacitor to an existing Nuxt app.

Add CAPACITOR

To add Capacitor to your web app, run the following commands:

cd my-nuxt-app
npm install @capacitor/core @capacitor/cli

Lets initialize Capacitor with our app’s information. This command below will generate 'capacitor.config.js’ file where we can add app information.

 npx cap init

Lets see how our capacitor.config.js files look

{
  "appId": "com.example.app",
  "appName": "MyNuxtApp",
  "bundledWebRuntime": false,
  "npmClient": "npm",
  "webDir": "www",
  "plugins": {
    "SplashScreen": {
      "launchShowDuration": 0
    }
  },
  "cordova": {}
}

LINK NUXT TO CAPACITOR

Use the –web-dir flag to set the web assets folder (the default is www)
Configuring this capacitor.config.json will link our nuxt app to capacitor. We need to change

"webDir": "www" to "webDir": "dist"

Also, we can configure our “appId” and “appName”. Now our app is ready to be compiled and build.

yarn run generate

yarn dev

We have successfully added Capacitor to our Nuxt.js app.

Lets add Platforms :

Electron

Run the command below in your root directory to install the platform for use with the @capacitor/cli

npm i @capacitor-community/electron

Lets initiate platform to create electron folder in our nuxt app.

npx cap add @capacitor-community/electron

So we have successfully added the electron platfrom to our application. Lets open it

npx cap open @capacitor-community/electron

Android & iOS

npx cap add android

npx cap add ios

Lets copy all of our web code from /dist to our native app directories for mobile platform functionalities. Specific modifications in IDE can made for each.

npx cap copy

Our code will be updated too with this.
For opening Android application :

npx cap open android

Make sure to have Android Studio with gradle build setup to generate apk.

For opening iOS application :

npx cap open ios

XCode will be opened and we can run our app.

Progressive Web App

Capacitor has a tiny development web server for local testing, but it’s recommended to run your web app using your framework of choice’s server tools.

npx cap serve

Generating resources

1. Create resources folder in root directory.

2. Add icon.png with size - 1024x1024 px Add splash.png with size - 2732x2732 px

3. So we have placed icon and splash in resources folder, now we need these in all sizes compatible with our android and ios platforms.

4. Lets add script to generate it and then sync it to platform.

5. Add the following command to scripts in package.json file of nuxt app

"resources": "cordova-res-generator -p android,ios && node resources/sync.js android"

As we see, we have used cordova-res-generator so lets install this generator by command

yarn add --dev cordova-res-generator

We have successfully add res-generator now we are ready to go but we still have node resources/sync.js android

This will sync the resources to android platform using sync.js, so lets add sync.js in resources where we have added our icon and splash

Sync.js

Copy the code from above mentioned Sync.js to generate sync.js inside resources.

so our resources will have these 3 :

We are ready to generate and sync now

yarn resources

🎉 Resources are generated and sync to platfrom - android 🎉

For iOS , we can make change in scripts of package.json as node/sync.js ios

Make sure to put logo in splash screen in middle as well as small for better resource generated results and optimized images.

Resources for Electron

Replace these assets icons from your icons

Packaging our Electron app to executable file

We will be using electron-builder so install using :

npm i electron-builder

Add script in package.json inside electron root folder.

"electron:pack": "npm run build && electron-builder build --dir",
"electron:build-windows": "npm run build && electron-builder build --windows",
"electron:build-mac": "npm run build && electron-builder build --mac"

We have added build script as well as for mac and windows application.

Run Command :

yarn electron:build-windows // windows

yarn electron:build-mac // mac

🔥 We have generated our execcutable files with this script 🔥

App name and package can be changed from build insidepackage.jsonof electron

Reference - Resource Generator- MexsonFernandes/nuxt-capacitor