Summary:
It was just adding unnecessary complexity. Users should just use standard React perf best practices, like `PureComponent` and `shouldComponentUpdate`.
This should be backwards compatible - existing `shouldItemUpdate` usage will just be ignored and should consider migrating to this pattern:
```
class MyItem extends React.PureComponent {
_onPress = () => {
this.props.onPressItem(this.props.id);
};
render() {
return (
<SomeOtherWidget title={this.props.title} onPress={this._onPress} />
)
}
}
...
_renderItem = ({item}) => (
<MyItem onPressItem={this._onPressItem} title={item.title} id={item.id} />
);
```
Which will automatically prevent re-renders unless the relavent data changes.
Reviewed By: yungsters
Differential Revision: D4730599
fbshipit-source-id: 0f61efe96eb4d95bb3b7c4ec889e3e0e34436e56
Summary:
After a fair bit of use, we have concluded that the `ItemComponent` mechanism is not worth the
hassle. Flow has trouble type checking it thoroughly, requiring an 'item' prop is annoying, and it
is very common to need to capture `this` anyway, e.g. for an `onPress` handler. A common pattern was
something like:
_renderItem = ({item}) => <MyItem foo={item.foo} onPress={() => this._onPress(item)} />};
...
ItemComponent={this._renderItem}
which wouldn't flow check the props and doesn't benefit from reusing components.
If we find some specific patterns that would benefit from the `ItemComponent` pattern, we can create
a new component that provides that API and wraps `FlatList` under the hood.
I'm going to do `SectionList` in a stacked diff.
Reviewed By: bvaughn
Differential Revision: D4625338
fbshipit-source-id: a4901f1c9d77e0115b0b8032b8c210f624e97ea3
Summary: Adding providesModule annotations to files that don't have a `providesModule` annotation but are in directories that packager crawls.
Reviewed By: cpojer
Differential Revision: D4612455
fbshipit-source-id: b23f0d6bbe2d26f480e93b56b67c6c8b1075e9f7
Summary:
The index is used to make sure the layout corresponds to the correct index, which can get
out of sync if cell layout is cached and then cells are re-ordered.
Reviewed By: bvaughn
Differential Revision: D4554721
fbshipit-source-id: 9acb37f390a6e40ad89f813b78f81b399ec11e9a
