Angular(SPA) Applications

AngularJs is a powerful javascript framework for building dynamic web applications. It became insanely popular nowadays. The good thing about Angular is that it has a set of ready-to-use modules to simplify building of single page applications.

Single page application (SPA) is a web application that fits on a single page. All your code (JS, HTML, CSS) is retrieved with a single page load. And navigation between pages performed without refreshing the whole page.

Pros

No page refresh

When you are using SPA, you don’t need to refresh the whole page, just load the part of the page which needs to be changed. Angular allows you to pre-load and cache all your pages, so you don’t need extra requests to download them.

Better user experience

SPA feels like a native application: fast and responsive.

Ability to work offline

Even if user loses internet connection, SPA can still work because all the pages are already loaded.


Cons

More complex to build

You need to write pretty much javascript, handle shared state between pages, manage permissions, etc.

SEO

To index your SPA app, search engine crawlers should be able to execute javascript. Only recently Google and Bing started indexing Ajax-based pages by executing JavaScript during crawling. You need to create static HTML snapshots specially for search engines.

Initial load is slow

SPA needs to download more resources when you open it.

Client should have javascript enabled

Of course, SPA requires javascript. But fortunately, almost everyone has javascript enabled.