support key extractor for version 3.1.2

.prettierrc.js

@@ -0,0 +1,4 @@
+module.exports={
+    "tabWidth": 2,
+    "singleQuote": true
+};

README.md

@@ -125,10 +125,11 @@ import Carousel from 'react-native-anchor-carousel';
 | ------ | ------ | ------| -----| ----| 
 | data | Array of data for rendering | Array |  [] | **Yes**|
 |renderItems | take each item from data and renders it. Function receives one agrument `{item,index}` and must return as         React.Element | Function | () => {}  | **Yes** |
-| initialIndex | Initial starting focused item of list | Number| 0 | No |  
+| initialIndex | Initial starting focused item of list | Number | 0 | No | 
+| keyExtractor | Key extractor for each item of list | Function |  (item, index) => index.toString() | No |
 | onScrollEnd |  Fired while scrollview end of scrolling | Function | ()=> {} | No |
 | pagingEnable | Enable or disable autor scroll to closest item | Boolean | False | No | 
-| containerWidth | Width of the carousel container box  | number | Screen width | **Yes** | 
+| containerWidth | Width of the carousel container box  | Number | Screen width | **Yes** | 
 | itemWidth | Width of each item in carousel | Number | 90% of screen width | **Yes** | 
 | separatorWidth| Width of separator in carousel (cause it only support horizontal side at the present time)| Number | 10 | No
 | inActiveScale | Value of the scale effect applied to inactive item | Number | 0.85 | No | 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-native-anchor-carousel",
-  "version": "3.1.1",
+  "version": "3.1.2",
   "description": "a simple swipeable carousel which anchor two sides",
   "main": "src/index.js",
   "directories": {

src/carousel.js

@@ -203,6 +203,7 @@ class Carousel extends Component {
       itemWidth,
       containerWidth,
       initialIndex,
+      keyExtractor,
       ...otherProps
     } = this.props;
     return (
@@ -213,7 +214,7 @@ class Carousel extends Component {
         data={data}
         decelerationRate={0}
         automaticallyAdjustContentInsets={false}
-        keyExtractor={(item, index) => index.toString()}
+        keyExtractor={keyExtractor}
         ref={(ref) => (this._scrollView = ref)}
         renderItem={this.renderItemContainer}
         style={[styles.container, { width: containerWidth }, style]}
@@ -238,6 +239,7 @@ Carousel.propTypes = {
   itemContainerStyle: ViewPropTypes.style,
   inActiveScale: PropTypes.number,
   inActiveOpacity: PropTypes.number,
+  keyExtractor: PropTypes.func,
   renderItem: PropTypes.func,
   onScrollEnd: PropTypes.func,
   pagingEnable: PropTypes.bool,
@@ -263,6 +265,7 @@ Carousel.defaultProps = {
   pagingEnable: true,
   minScrollDistance: 25,
   itemContainerStyle: {},
+  keyExtractor: (item, index) => index.toString(),
   renderItem: () => {},
   onScrollEnd: () => {},
   onScrollBeginDrag: () => {},