James Ide 7f51f9c8a9 [Navigator] Support the ref prop on scene roots
Summary:
Navigator overrides the `ref` prop of scene components so that it can call `onItemRef` and do internal bookkeeping. With callback refs, we can additionally call the original value of the `ref` prop as long as it's a function (that is, string refs are not supported). Note that the `ref` prop is moved to `reactElement.ref` out of `reactElement.props.ref`, which is why this diff accesses `child.ref`.

This diff adds support for callback refs and warns helpfully if a string ref was provided. It should be completely backwards compatible since scenes couldn't have been relying on the `ref` prop before.

cc @ericvicenti

Closes https://github.com/facebook/react-native/pull/1361
Github Author: James Ide <ide@jameside.com>

@public

Test Plan:
 Write a renderScene implementation that puts a callback ref on the root component:
```js
renderScene() {
  return <View ref={component => console.log('yes! this is called')} />;
}
```
2015-05-21 11:01:09 -08:00
..