Web Apps: Vue/Parcel/Workbox

Framework & Tools

Vue

We will use the Vue.js ecosystem for the heavy lifting:

Vue.js will handle our views by providing a declarative approach in defining them and separating the code in single-file-components,
VueX will be used for state management
Vue Router will be used to handle the SPA routes

Node.js

Node.js will provide support for the bundling utilities and all other utilities that might be required

Parcel

Parcel bundler will be used to build and bundle the application

Workbox

Workbox will handle the service-worker details.

Files layout

./src will contain all source code for this project.

./src/web will contain the source code for the web application (the html client).
./src/db (optional) will contain any database initialization scripts
./src/server (optional) will contain any server-side projects

./dist will contain all generated artifacts and should be ignored in git

./dist/web will contain the build and bundled web application.
./dist/db (optional) will contain any artifacts generated by the database scripts
./dist/server (optional) will contain any server-side projects (compiled)

./.cache will be generated by parcel and should be ignored in git
./node_modules will be generated by npm or parcel and should be ignored in git

The code

The code can be found in project's github repo

Javascript dependencies

Entry point (index.html)

./src/web/index.html is our entry point and just links everything together

<link rel="manifest" href="./manifest.webmanifest"> links the .webmanifest file
<div id="vueapp"></div> defines vue.js mounting point
<script src="./index.js"></script> loads the script that contains the vue.js application
navigator.serviceWorker.register('/service-worker.js'); registers the service worker script

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="ie=edge">
        <link rel="manifest" href="./manifest.webmanifest">
        
        <title>Vue.js Single Page Application Template</title>       
    </head>

    <body>
        <div id="vueapp"></div>          
        
        <script src="./index.js"></script>
        <script>
            if ('serviceWorker' in navigator) {
                window.addEventListener('load', () => {
                    navigator.serviceWorker.register('/service-worker.js');
                });
            }
        </script>
    </body>
</html>

./src/web/index.html

Manifest

./src/web/manifest.webmanifest describes the application and is required for the application to be considered a PWA.

It's important to maintain the .webmanifest extension for parcel compatibility.

{
    "name": "My application name",  
    "short_name": "app",

    "start_url": "/",
    "background_color": "#3367D6",
    "display": "standalone",
    "scope": "/",
    "theme_color": "#3367D6",
    
    "icons": [
        {
            "src": "/res/app-256.png",
            "type": "image/png",
            "sizes": "256x256"
        }
    ]
}

./src/web/manifest.webmanifest

Service Worker (Workbox)

./src/web/service-worker.js implements the service worker that is required for considering the application to be a PWA. Google's workbox is used. Workbox defines multiple strategies (network-first, cache-first, and Stale-while-revalidate). In this example all resources are served using the network-first strategy since this is the most responsive approach and maintains the capability to work offline.

console.log("service-worker.js")
// import service worker script
importScripts('https://storage.googleapis.com/workbox-cdn/releases/4.2.0/workbox-sw.js');

// Network First
[ 
    '/$',  // Index 
    '/*',  // Anything in the same host
    '.+/*' // Anything in any host 
]
.forEach(mask => {
    workbox.routing.registerRoute(
        new RegExp(mask),
        new workbox.strategies.NetworkFirst( { cacheName: 'dynamic' } ) 
    );
});

./src/web/service-worker.js

Vue.js binding

./src/web/index.js is used to bind the vue.js application and our css (in scss). It imports the vue.js framework, our vue.js application code (app.vue) and our styles (styles.scss) - All these files are located in ./src/web/ but we are using relative paths in the imports. Finally we mount our vue.js application to the corresponding div element.

import Vue from 'vue';

import App from './app.vue';
import './style.scss'

new Vue(App).$mount('#vueapp')

./src/web/index.js

Vue Application

./src/web/app.vue contains our vue.js application as a single file component.

In the `<template>` we construct a simple navigational menu and the router-view which is the host for our single page application, all other pages are mounted in the router-view element. In this template we are using pug instead of html.

In the <script> we import the vue.js framework and two custom modules, the _router.js and the _store.js and we create our vue.js application by extending the default vue.js application with the store and router modules we just loaded.

In the <style> we providing some local (scoped) styling for the menu using scss (which our bundler will convert to css)

<template lang="pug">
    div
        nav.navbar
            router-link(to="/") home
            router-link(to="/profile") profile
            router-link(to="/about") about
        router-view
</template>


<script>
    import Vue from "vue";
    import {router} from './_router.js';
    import {store} from './_store.js'
   
    export default Vue.extend({ 
        store: store,
        router: router    
    });    
</script>


<style lang="scss" scoped>
    
    .navbar {
        text-align: center;
        
        * + * {
            margin-left: 8px;
        }
    }
</style>

./src/web/app.vue

Router

./src/web/_router.js configures and initializes vue-router by loading all pages and declaring their routes.

import Vue from "vue";
    
import VueRouter from 'vue-router';

Vue.use(VueRouter)

// 1. Import Components
import home    from './vues/home.vue'
import about   from './vues/about.vue'
import profile from './vues/profile.vue'

// 2. Define some routes
const routes = [
    { path: '/'       , component: home    },   
    { path: '/profile', component: profile },
    { path: '/about'  , component: about   }
]

// 3. Create & Export the router 
export const router = new VueRouter({
    routes: routes
})

Store

./src/web/_store.js configures and initializes the vuex store module. It declares the global state and the available mutations. The vuex allows for global state to be modified by all view components (through the mutations) while maintaing the reactivity of the framework. (ie committing a mutation will update all components that are affected by the state change).

import Vue from 'vue';
import Vuex from 'vuex';

Vue.use(Vuex);

export const store = new Vuex.Store({
    state: {
        name: 'Unknown'
    },

    // Usege: $store.commit('mutationan', parameter)
    mutations: {
        setName(state, name) {
            Vue.set(state, 'name', name);
        }
    }
});

./src/web/_store.js

Pages

We have three pages in our example, home and about are almost identical, both are rendering the name property of the store.

profile provides an input box where the user an type his name and instantly updates the global state when the value of the input changes.

./src/web/vues/about.vue

<template lang="pug">
    div 
        h1 About
        p  Welcome: {{$store.state.name}}
</template>

<script>
    export default {
        
    }
</script>

./src/web/vues/about.vue

./src/web/vues/home.vue

<template>
    <div> 
        <h1>Home</h1> 
        <p> Welcome: {{$store.state.name}}</p>
       
    </div>   
</template>


<script>
    export default {
    }
</script>

./src/web/vues/home.vue

./src/web/profile.vue

<template lang="pug">
  div 
    h1 Profile
    p  Welcome: {{$store.state.name}}
    div.form 
      table
        tr
          td Name
          td
            input(:value="$store.state.name" @input="$store.commit('setName',$event.target.value)")
</template>

<script>
    export default {
        
    }
</script>
<style lang="scss" scoped>
    .form {
        display: flex;
        justify-content: center;
    }
</style>

./src/web/profile.vue

Developing

The following steps are required in order to develop on this template

Download or clone the code
Install parcel npm i -g parcel-bundler
Install project dependencies npm install (in project root)
Run the dev script npm run dev