Create PWA (Create a Progressive Web Application)
Easily create a Progressive Web Application
About
create-pwa
is a module for quick scaffolding and producing of progressive web applications.
create-pwa
adds the minimum required boilerplate which your app requires in order to become a PWA.
create-pwa
can be used with existing applications or can be the first thing one does when starting a new app.
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Dependencies
In order to use this module, you must have NodeJS installed and NPM or Yarn available.
You also need a bash shell installed and configured - default on OSX and linux or Git bash on Windows.
Install
# Using NPM:
npm i create-pwa --save-dev
# Using Yarn
yarn add create-pwa --dev
Arguments
icon
: Specifies a relative path to the application icon. Should be a.png
file.
This path is relative to the folder you are located in. It is recommended that the icon file is at least a 512x512 pixels square.
The icon
argument is not required.
If the icon
argument is not provided, the default icon is used.
launch
: Specifies a relative path to the application launch (splash) screen. Should be a.png
file.
This path is relative to the folder you are located in. It is recommended that the launch is at least 3200x3200 pixels square and the actual content (for example brand image) is located in the middle of the image in a square with dimensions up to 500x500 pixels.
The launch
argument is not required.
If the launch
argument is not provided, the default launch screen is used.
output
: Specifies a relative path to the output directory.
This path is relative to the folder you are located in.
The output
argument is not required.
If the output
argument is not provided, the default value for it is empty string (the root of your project or the location of your package.json
file).
Usage
If you want to use if from the command line, you should first install Create PWA globally:
npm i -g create-pwa
# or
yarn global add create-pwa
Then, navigate to your application’s folder: Then run the install command (see above)
cd your/app/folder
create-pwa --icon="./icon.png" --launch="./launch.png"
You can also use create-pwa
as a package.json script (in this case you don’t need to install the package globally):
{
"scripts": {
"pwa": "create-pwa --icon=\"path/to/your/icon.png\" --launch=\"path/to/your/launch.png\""
}
}
The above commands will generate:
- a
manifest.json
and aservice-worker.js
files - several (8) png icons in the
/icons/
folder in your app’s root folder - several (19) favicons in the
/favicons
folder in your app’s root folder - several (20) launch screen images in the
launch-screen
folder in your app’s root folder - a
config.xml
file in your app’s root folder - this file is required in Microsoft’s browsers
You can edit the contents of the manifest.json
and service-worker.js
files.
Their default content is based on industry’s best practices and is highly opinionated.
In order to create a customized experience for your users, feel advised to revise and edit the contents of the above files.
When the files(manifest.json
and service-worker.js
) are ready for production, you need to let the world know about them:
Feel adviced to edit the content of the <TileColor>
tag in the config.xml
file as it matches the color of your application’s status bar on Chrome (found in the <meta name="color" />
tag);
- Add the following to the
head
of your HTML file(s):
<link rel="manifest" href="manifest.json" />
You can read more about the Web App Manifest here.
- Add the following snippet to your application’s JavaScript bundle or place it in a
script
tag just before the closing</body>
tag in your HTML file(s):
if ('serviceWorker' in navigator) {
window.addEventListener('load', () => {
navigator.serviceWorker.register('./service-worker.js').then(
registration => {
console.log(`ServiceWorker registration successful with scope: ${registration.scope}`);
},
error => {
console.log(`ServiceWorker registration failed: ${error}`);
}
);
});
}
The code above checks for service worker support and then registers a service worker located in the service-worker.js
file in the root of the project.
You can read more about Service Workers here.
After that, add references to all icons which were generated by create-pwa
:
- Add the following favicons and meta tags in the
head
of your HTML file(s):
For more info about the favicons and meta tags below see here.
View favicons and meta tags
```html ```- (Optional) Add the following launch screens in the
head
of your HTML file(s):
View launch screens
```html ```In order to have the launch screens shown on an iOS device you also need to tell the device it is dealing with a web app:
<meta name="apple-mobile-web-app-capable" content="yes" /> <meta name="mobile-web-app-capable" content="yes" />
The formet works on Safari on all iOS devices. The latter works on Google Chrome on all iOS devices.
Android devices show splash screen based on the data provided in the manifest.json
file: icons
, name
, etc.
- (Optional) Add the following attribute to your
html
tag:manifest="<YOUR_APP_NAME>.appcache"
. It should look something like this:
<html lang="en" manifest="create-pwa.appcache">
<!-- More awesome HTML code here -->
</html>
This will enable application cache and will cache all files listed in the .appcache
file.
Application cache is currently deprecated in most evergreen browsers and will probably be removed soon.
This, however, does not mean that you can not use it in older browsers (for example IE 11).
You can read more about Application Cache here
More info
There is a lot information about Progressive Web Applications on the Internet. In order to comply with browser’s requirements and pass the audits you need to check out and fulfill the PWA Checklist.
The entries listed in Baseline Progressive Web App Checklist are mandatory and without them your web app will not qualify as a PWA.
If you wish to test your web app’s compliance, you can use the Chrome’s built-in Lighthouse tool (found under the Audits tab in the Developer tools).
NodeJS API
You can generate each of the components above separately using the Create PWA API in NodeJS:
- To create only an
appcache
file:
const { setAppCache } = require('create-pwa');
const appName = 'Your application name';
const distFolder = 'dist';
setAppCache(appName, distFolder);
The generated appcache
file contains references to the application icons and application launch screens. You must have these already generated otherwise you must edit your appcache
file and remove them.
- To create only the application icons:
const { setIcons } = require('create-pwa');
const appIcon = require('fs').resolve(__dirname, './your_icon.png');
const distFolder = 'dist';
setIcons(appIcon, distFolder);
The generated icons are located in the /icons
folder.
- To create only the launch screens:
const { setLaunchScreens } = require('create-pwa');
const launchScreen = require('fs').resolve(__dirname, './your_launch_screen.png');
const distFolder = 'dist';
setLaunchScreens(launchScreen, distFolder);
The generated files are located in the /launch-screens
folder.
- To create only manifest file:
const { setManifest } = require('create-pwa');
const appName = 'Your application name';
const distFolder = 'dist';
setManifest(appName, distFolder);
The generated manifest.json
file contains references to the application icons. You must have these already generated otherwise you must edit your manifest.json
file and remove them.
- To create only favicon files:
const { setFavicons } = require('create-pwa');
const appIcon = require('fs').resolve(__dirname, './your_icon.png');
const distFolder = 'dist';
setFavicons(appIcon, distFolder);
The generated files are located in the /favicons
folder.
- To create only service worker file:
const { setServiceWorker } = require('create-pwa');
const appName = 'Your application name';
const distFolder = 'dist';
setServiceWorker(appName, distFolder);
The generated service-worker.js
file contains references to the application icons and application launch screens. You must have these already generated otherwise you must edit your service-worker.js
file and remove them.
LICENSE
MIT