In the latest Google I/O the Polymer team introduced the first production-ready version of Polymer(1.0) and as they said many parts have been completely rewritten
and is now faster and better than ever.
Let me check the migration instructions, oh…
If you didn’t follow along with the latest pre-releases(0.7, 0.9) and stayed on the 0.5.x branch(like me), everything will be broken, let me name a few core changes :

  • The way you define elements
  • Shadow DOM
  • Element attributes
  • DOM manipulation
  • Data binding
  • Styling
  • Renamed and removed elements

Side advice: if you have something small and of no big significance just go over the docs again, relearn the tool and rewrite it, it’s not worth the pain of migrating.

But the biggest problem for me was that many great custom elements are left on the 0.5.x branch, so make sure you read the source of everything you use or it’s going to be hell.

Now the hands on good parts :

  • Documentation greatly improved
  • The new element cart-like catalog is great
  • APIs are generally cleaner(for the most part)
  • The new element naming convention makes more sense now
  • Polyfills(webcomponents.lite.js) work much better(on firefox at least)


Early adopters will have a bit of a hard time if you didn’t follow along closely, but in general the direction we are heading is bright!
Make sure you watch the I/O videos, reread the docs and the migration page carefully and watch out for dead elements!

Have fun!

PS: core-scaffold is gone.