swipeDirectionCallback is not a function error #155

Exemples/package.json

@@ -11,7 +11,7 @@
         "prop-types": "^15.5.10",
         "react": "^16.2.0",
         "react-native": "^0.49.5",
-        "react-native-deck-swiper": "^1.5.12"
+        "react-native-deck-swiper": "^1.5.13"
     },
     "devDependencies": {
         "babel-jest": "19.0.0",

README.md

@@ -308,3 +308,23 @@ const styles = StyleSheet.create({
   }
 });
 ```
+
+## Updating props on card content? (dynamic card content)
+
+Card properties may change, including on already swiped cards, which would yield no effects to users as the cards would no longer be displayed [based on [initial issue](https://github.com/alexbrillant/react-native-deck-swiper/issues/153)].
+
+A possible fix for the situation is setting the _cardIndex_ on the parent component whenever deck re-renders are needed.
+
+```
+const { cardIndex } = this.props;
+return (<Swiper
+ref={swiper => {
+  {...customSwiperProps}
+  cardIndex={cardIndex}
+}}
+/>
+```
+
+Passing along the _cardIndex_ to the swiper will allow external changes on the property, thus triggering a re-render of the deck of cards. All _onSwipe_ callbacks return the _cardIndex_ that can be used to push the updated _cardIndex_ to app state (redux or something else).
+
+By making sure that external changes on the cardIndex match those the swiper performs (increment on swipes, decrement on swipeBack) one can ensure no re-renders occur when not needed.

Swiper.js

@@ -492,7 +492,9 @@ class Swiper extends Component {
     const previousCardIndex = this.state.firstCardIndex
     this.props.onSwiped(previousCardIndex)
 
-    swipeDirectionCallback(previousCardIndex)
+    if (swipeDirectionCallback) {
+      swipeDirectionCallback(previousCardIndex)
+    }
     if (swipedAllCards) {
       this.props.onSwipedAll()
     }

package.json

@@ -1,6 +1,6 @@
 {
     "name": "react-native-deck-swiper",
-    "version": "1.5.12",
+    "version": "1.5.13",
     "description": "Awesome tinder like card swiper for react-native. Highly Customizable!",
     "main": "index.js",
     "scripts": {