Progressive Web Apps
What if you could develop your app just once but for multiple platforms and devices? The answer to this question comes up via Progressive Web Applications. These applications are developed using web APIs in the classical progressive enhancement framework and they can run on every device via web; hence, they omit any need for native development of the application and so resulting in lower time and financial expenses. Aside from the expenses, their high level of responsiveness and interactivity ends in the same experience of a native app by the users. These sort of apps are professionally distinguished by their special features, which include responsiveness, linkability, discoverability, installability and etc. You might wonder what these features denote and how a web application is recognized as a PWA. Here are a PWA features and their laconic definition by Google developers as listed below:
Works for every user, regardless of browser choice, using progressive enhancement principles.
Fits any form factor: desktop, mobile, tablet, or forms yet to emerge.
Service workers allow offline uses, or on low quality networks.
Feels like an app to the user with app-style interactions and navigation.
Always up-to-date due to the service worker update process.
Served via HTTPS to prevent snooping and ensure content hasn't been tampered with.
Identifiable as an “application” by manifest.json and service worker registration, and discoverable by search engines.
Ability to use push notifications to maintain engagement with the user.
Provides homescreen icons without the use of an App Store.
Can easily be shared via a URL, and does not require complex installation.
One of the key elements in a PWA is that is must be able to work in offline mode too. Service workers store the Basic User Interface of the responsive web design in the browser's offline cache. This model allows for PWAs to maintain native-like use with or without web connectivity. This can improve loading time, by providing an initial static frame, a layout or architecture into which content can be loaded progressively as well as dynamically.
There are a number of technologies to create a PWA. The minimal set of fundaments and the backbone to develop a PWA include three key components as listed bellow:
The app has to run under Http/https protocol.
Web App Manifest
An app manifest file should describe the metadata and resources connected to the app. This includes your app name, icons, images as well as other application configurations. To make the browser to include your resources and to apply configurations, you just need to mention the manifest file in the main file of your website.
Service workers are a type of web workers that work independent from the browser thread; thus, they can handle push notifications, requests, synchronization, data caching and offline support. Service workers provides a programmatic way to cache app resources. The programmatic API allows developers to decide how to handle caching and provides a much more flexible experience than other options.
There are also various other optional components such as, Web Storage, WebAssembly, Databases, AppCache and etc which are arbitrarily involved or included with respect to the project requirements.
Through our professional experiences and with regard to the needs and the goals of our customers, we ultimately sum all the features and components described above, up in a highly responsive and interactive application that can work on every device or platform very fast while enjoying all the broad functionalities of a web application, without any need for installation and submission.