Merge pull request #437 from iKrushYou/master

Provide clarity on necessity of key property in the data array

Author: jemise111

README.md

@@ -59,6 +59,15 @@ The application under ./SwipeListExample will produce the above example. To run
 ```javascript
 import { SwipeListView } from 'react-native-swipe-list-view';
 
+//... note: your data array objects MUST contain a key property 
+//          or you must pass a keyExtractor to the SwipeListView to ensure proper functionality
+//          see: https://reactnative.dev/docs/flatlist#keyextractor
+
+  this.state.listViewData = Array(20)
+    .fill("")
+    .map((_, i) => ({ key: `${i}`, text: `item #${i}` }));
+
+//...
 render() {
     return (
         <SwipeListView

components/SwipeListView.js

@@ -654,6 +654,10 @@ SwipeListView.propTypes = {
      * Use Animated.Flatlist or Animated.Sectionlist
      */
     useAnimatedList: PropTypes.bool,
+    /**
+     * keyExtractor: function to generate key value for each row in the list
+     */
+    keyExtractor: PropTypes.func,
 };
 
 SwipeListView.defaultProps = {

docs/SwipeListView.md

@@ -1,3 +1,4 @@
+
 # `<SwipeListView />` API
 
 A List that renders `<SwipeRow />`s
@@ -6,6 +7,7 @@ A List that renders `<SwipeRow />`s
 
 | Prop | Notes | Type | Signature (func) | Default |
 | --- | --- | --- | --- | --- |
+| `data` | List of objects to be passed into the `renderItem` and `renderHiddenItem` functions. Each item must include a unique `key` property or `keyExtractor` must be implemented to ensure full functionality. | `array` ||
 | `useSectionList` | Render list using React Native's `SectionList` | `bool` | | `false` |
 | `renderItem` | How to render a row in a FlatList. Should return a valid React Element. | `func` | `{ rowData: any, rowMap: { string: SwipeRowRef } } : ReactElement` |
 | `renderHiddenItem` | How to render a hidden row in a FlatList (renders behind the row). Should return a valid React Element. This is required unless `renderItem` returns a `<SwipeRow>` (see [Per Row Behavior](https://github.com/jemise111/react-native-swipe-list-view/blob/master/docs/per-row-behavior.md)). | `func` | `{ rowData: any, rowMap: { string: SwipeRowRef } } : ReactElement` |
@@ -60,3 +62,5 @@ A List that renders `<SwipeRow />`s
 | `shouldItemUpdate` | Callback to determine whether component should update | `func` | `{ currentItem: any, newItem: any }` |
 | `useNativeDriver` | useNativeDriver: `true` for all animations | `bool` | `true` |
 | `useAnimatedList` | Use Animated.Flatlist or Animated.Sectionlist | `bool` | `false` |
+
+See [FlatList](https://reactnative.dev/docs/flatlist) for all other inherited props