I have over the past months spent quite a bit of time working with Angular 2.0 by writing sample components and going through the Angular 2.0 source code. At this point I have decided to write down some of my thoughts around my experiences with Angular 2.0. Keep in mind, these are just my own personal experiences, so I am very interested in hearing from other developers who might have totally different views on this.
As I have stated before, I really like some of the new conventions in Angular 2.0. However, what gets me is how similar Angular 1.x and Angular 2.0 are if you trim it down to just concepts – ignoring syntax differences.
I want to emphasize that my issue is not primarily with the new breaking syntax since converting syntax is not really a hard problem with the right editor. My issue is more with the Angular team's decision to create a brand new framework where they have to redo everything – even the things they did right the first time around. In my opinion the biggest disadvantage of going with a fresh start is a huge delay in their time to market. We are already seeing new frameworks like Aurelia and React (with supporting patterns), emerging as very viable alternatives to Angular 2.0.
I am not trying to discount the new features and conventions in Angular 2.0. I fully support most of them, but my argument is that it should have been introduced incrementally in the Angular 1.x codebase. Features of Angular 1.x that are considered bad practices should be deprecated as part of this effort. This is a practice we're already seeing when it comes to promise methods like success and error which are headed for deprecation.
One might argue that some of the new features like bindings and change tracking break the conceptual parity between Angular 1.x and Angular 2.0. This is ok since you could have included meta in the bindings to opt in to one-way, two-way or one-time bindings. WPF in .Net is an example of a framework that went in this direction. I have argued from the very beginning that one-time, for performance reasons, should be default. However, I understand that this ship has sailed. Some disagree with me here, but my argument is that one should opt into change tracking where it's needed, instead of opting out where it's not needed.
I realize it might not be clear what I mean when I say the concepts are so similar between Angular 1.x and Angular 2.0. I think the rich API surface in Angular 1.x hides this a bit since you have to write your Angular 1.x code a certain way to see the similarity. My argument is that the similarity is really striking if you write Angular 1.x directives with “controllerAs” style controllers – consumed by the directive. Not everyone realizes this, but new features like bindToController and controllerAs have made the interaction between the directive portion and the controller seamless. It also gives you that sought after Angular 2.0 component feel. I have done a more in depth comparison in the following article.
I like the new direction of using TypeScript for Angular 2.0, but I also think it may make the two frameworks seem more different than they really are. After all you could be writing Angular 1.x in TypeScript as well. Perhaps a comparison of Angular 1.x and Angular 2.0, both in TypeScript, would make them seem even more similar.
As with all new major versions there are a ton of new improvements in Angular 2.0. Some of the exciting new features include components decoupled from the runtime environment. This will likely give us some of the same benefits we see out of React where you can map a component to completely different underlying platforms (server, mobile and browser). Another big one for large applications is native built in support for lazy loading. In Angular 1.x we have to rely on third party libraries like ocLazyLoad to achieve this. That said, these new features don't seem to break with my previous argument that this could have been released incrementally as a natural evolution of the 1.x line.
Despite my criticism I am still certain that the final Angular 2.0 product will eventually be a success. As I stated earlier, my complaint is not with the breaking changes, but rather with how they are delivered. I personally would have tried to evolve the existing framework rather than via a clean slate that adds months, maybe years, to the release timeline.
Anyway, this was just my take on this. I would really like to hear from other developers on this topic and learn different perspectives. My views are for the most part a result of working with Angular 2.0 in my Angular 2.0 repo on Github. Check out my live demo here if you are interested.
After doing some more research I have come to the conclusion that it was the right decision to implement Angular 2.0 as a brand new project. The core foundation of Angular 2.0 is just too different to implement it as an extension of Angular 1.x. I also believe that the ngUpgrade approach will be flexible enough to greatly reduce the pain of migrating to Angular 2.0.
So, to answer my own question, yes I do think Angular 2.0 is worth it. After learning more about the specifics of the improvements I am very exited to continue to work with Angular 2.0.