These preparation steps are all about making the code more decoupled, more maintainable, and up to speed with modern development tools.
That means the preparation work will not only make the eventual upgrade easier, but will also generally improve our Angular 1 applications.
One of the keys to a successful upgrade is to do it incrementally, by running the two frameworks side by side in the same application, and porting Angular 1 components to Angular 2 one by one.
This makes it possible to upgrade even large and complex applications without disrupting other business, because the work can be done collaboratively and spread over a period of time.
Having an existing Angular 1 application doesn't mean that we can't begin enjoying everything Angular 2 has to offer.That's because Angular 2 comes with built-in tools for migrating Angular 1 projects over to the Angular 2 platform.It contains a wealth of information about how to write and organize Angular code - and equally importantly - how not to write and organize Angular code.Angular 2 is a reimagined version of the best parts of Angular 1.
Some applications will be easier to upgrade than others, and there are ways in which we can make it easier for ourselves.It is possible to prepare and align Angular 1 applications with Angular 2 even before beginning the upgrade process.