One of the most important things is that Angular 4.0 doesn’t change that much. In Angular 4.0, some under the hood changes, some improvements, and performance improvements have been done. There is no Angular 3: Angular skipped to version 4 in order to sync up the Angular router’s version which was already in 3.X.
According to Angular change-log the “Angular 4.0 release is backward compatible and will work with your existing code, but you may have use cases they haven’t anticipated”.
There are plenty of new features, most of which are small. One of the biggest improvements was in the way Angular’s Ahead-Of-Time (AOT) compiler generates code.
At ng-conf 2017 Keynote stage Minar started off the keynote by answering the question “why do we build Angular?”.
What we are trying to do is to enable creations of applications that people love to use, that people feel good about using. And we want these applications to be built by developers who love what they do, who love building these applications, who they feel productive. And we want developers to be part of the community that is welcoming and inclusive.
This version of Angular has also made the TypeScript jump to version 2.1. Previously, TypeScript 1.8 was used and there was no backward compatibility. Other important changes are:
- Animation pulled to its own package
- Angular Universal (server-side rendering) is back in sync with Angular and is now maintained by the Angular team
- Source Maps for Templates
- Improved *ngIf and *ngFor
- View Engine changes
- Smaller and faster
This release brings some nice features and a really welcome improvement of the generated code size, for the price of very few breaking changes that should not impact you a lot. The migration has been quite smooth for us.
P.S: You can watch full ng-conf 2017 here