0.8 Compatibility

[mbleigh]

This is incomplete work toward 0.8 compatibility for firebase-element. I'm submitting it as a pull request to start discussion about some of the things that may need to change.

Presently demos/firebase.html will load data but doesn't persist it -- at all. I think I may not understand how Polymer 0.8 property binding works when trying to use standard <form> elements, so any insight would be appreciated.

I also ended up needing to load observe.js separately since I don't think it's part of Polymer anymore. Since 0.8 is moving away from Object.observe, should another solution be used in its place for firebase-element?

In any case, WIP feel free to poke around.

[addyosmani]

cc @kevinpschaaf

[mbleigh]

After some consideration, I don't think it probably makes sense to port the existing paradigm for firebase-element to 0.8. Right now my guess for a best-bet would actually be to make a Polymer mixin for Firebase that allowed you to bind to specific properties. Something like:

Polymer({
  is: "app-user",
  mixins: [PolymerFire({
    base: "https://example.firebaseio.com/users",
    properties: ["name", "email"],
    locationProperty: "id"
  })],
  properties: {name: String, email: String},
  created: function(){ this.bindRef() }
});

Where the mixin is a factory that takes the properties to bind as well as a property that can serve as a dynamic location identifier.

I'll probably build this regardless of the direction of firebase-element, just thought I'd share.

[mbleigh]

As promised, I couldn't resist building out a prototype of my suggestion above: https://github.com/divshot/polymerfire

I think this is probably a more idiomatic way to approach Firebase data in a Polymer 0.8 world (without Object.observe it seems almost impossible to have a "zero JS" way to bind).