Progressive Web Apps – Web App Manifest

The web app manifest is a simple JSON file that gives you, the developer, the ability to control how your app appears to users in areas where they would normally see apps in mobile devices.

Screenshot_20180821-000049

 

Web app manifests are part of a collection of web technologies called progressive web apps, which are websites that can be installed to a device’s homescreen without an app store, along with other capabilities like working offline and receiving push notifications.

And, more importantly, how it behaves when it’s launched from the home screen.

Installs to the homescreen

When a user clicks “Add to homescreen”, they will see the app being added on the homescreen.

At a minimum, the manifest must contain the name of the app and a short_name.

The short_name is used on the home screen and in other places where there is limited space.

It also needs the start_url, the URL the app should open when launched from the home screen.

Defining the manifest metadata

{
"short_name": "Pandiyan",
"name": "Pandiyan Murugan",
"icons": [{
"src": "/img/portrait_small.jpg",
"type": "image/jpg",
"sizes": "192x192"
},
{
"src": "/img/portrait.jpg",
"type": "image/jpg",
"sizes": "512x512"
}
],
"start_url": "/?source=pwa",
"background_color": "#3367D6",
"display": "standalone",
"scope": "/",
"theme_color": "#3367D6"
}

Make sure, the page you specify is cached as part of the app shell. Otherwise, you won’t get the benefits of a cached app shell and your app won’t work offline.

One quick tip.

To track the number of users who are launching your app from their home screen, you can add a query string to the end of your URL.

And use any analytics to track launches, with that query string.

But don’t forget to ensure that you’ve cached the URL with the query string, in your service worker.

Adding icons and Splash screen color

Finally, we need to provide a set of icons for things like the home screen icon and the tab switcher, and splash screen.

The icons parameter takes an array of icons and must include the source, the size of the icon, and the type.

For example, image/jpg.

I recommend providing eight icon sizes,

48 x 48, 96 bx 96, 128 bx 128, 144 x 144,

192 x 192, 256 x 256, 384 x 384 and 512 x 512.

Just make sure you have icons for 1x, 2x, 3x and 4x devices.

Chrome uses the 48 device independent pixel icons for the home screen icon and the tabs footer. And the 128 device pixel icons for the splash screen.

Those are the minimum requirements. But there are a few other helpful things that you should set in the manifest.

The background color, and theme color are used by the browser along with an icon, as part of the splash screen.

Shown the instant the web app is launched, until its first render. As we provide the splash screen color as blue in manifest. The splash screen, icon and short name is displayed while the browser is rendering the application. (http://pandiyan.cool)

Once the app is loaded, the theme color tells the browser, what color to display in the UI elements such as the address bar or the notification tray.

Display and orientation property give you control over how the app is displayed. For example, you can hide the address bar and the back and forward buttons, by setting “display”: “standalone”. Or if you’re building a game that works better in landscape, you can force landscape view by specifying, “orientation”: “landscape”.

Web apps will launch full-screen with no vestiges of a browser. The URL will not be present, nor will traditional browser actions such as bookmarking and navigation controls.

Linking the manifest

When you have created the manifest add a link tag to all the pages that encompass your web app:

<link rel="manifest" href="/manifest.json">

Manifest metadata in browser

To confirm whether the manifest is properly, we can use the chrome DevTools to view the manifest as below

(Switch to Application tab in the Chrome Dev Tools)

manifest

Happy Coding!

Angular 5 Tutorial 02 – Creating Hello World Application

In this post, we are going to discuss how to setup development environment and create an initial angular app using CLI.

Whenever I’m creating a new application, I always prefer some standard folder structure or use file generator like Yeoman.

A quick start tool always helps the developer to save their valuable time and use those time efficient way on improving the quality of the application.

Angular provides us Angular CLI which is a command line interface tool that can create a project, add files, and perform a variety of ongoing development tasks such as testing, bundling, and deployment.

Using this CLI, we can create apps with a working condition which uses best practices suggested by Angular Team.

To create an Angular application using Angular CLI, all we need is to follow the below steps:

1. Install Node js and npm on your machine.

Visit Node.js web page and download installer. Once you’ve installed nodejs, the npm will get installed along with it.

2. Verify the compatible version

Angular CLI requires the minimal version of node 6.9.x and npm 3.x.x.

We can check the version of node and npm using following commands.

node -v

npm -v

01

3. Install Angular CLI

Run the following command to install Angular CLI globally.

npm install -g @angular/cli

-g flag is used to install the package globally in the npm.

Once we installed CLI globally, we can confirm whether the tool installed successfully by using the following command.

ng -v

 

4. Create a project

Now, creating a project becomes very simple. We have to run following command,

ng new cool-app

  • cool-app is the name of the project.

 

new-app

Once the files has been created, the CLI will start installing npm packages automatically. Wait until the packages getting installed, it will take a bit of time to complete the process.

The folder and file structure will looks as follows

code_ng-app4.png

5. Serve the application

Once the dependencies are installed, traverse to the created projected and serve the application using the following commands.

cd cool-app

ng serve –open

The ng serve command launches the server, watches your files, and rebuilds the app as you make changes to those files.

Using the –open (or just -o) option will automatically open your browser on http://localhost:4200/.

The default page will get open with the greeting message.

 

CoolApp.png

 

Stay connected and Keep supporting. 🙂

Happy Coding!

 

In the next post, we can discuss the architecture of the angular application.