Merge pull request #1272 from randallreedjr/before-change-current-slide

Before change current slide

examples/SlideChangeHooks.js

@@ -3,6 +3,7 @@ import Slider from "../src/slider";
 
 export default class SlideChangeHooks extends Component {
   state = {
+    oldSlide: 0,
     activeSlide: 0,
     activeSlide2: 0
   };
@@ -13,12 +14,16 @@ export default class SlideChangeHooks extends Component {
       speed: 1000,
       slidesToShow: 1,
       slidesToScroll: 1,
-      beforeChange: (current, next) => this.setState({ activeSlide: next }),
+      beforeChange: (current, next) =>
+        this.setState({ oldSlide: current, activeSlide: next }),
       afterChange: current => this.setState({ activeSlide2: current })
     };
     return (
       <div>
         <h2>beforeChange and afterChange hooks</h2>
+        <p>
+          BeforeChange => oldSlide: <strong>{this.state.oldSlide}</strong>
+        </p>
         <p>
           BeforeChange => activeSlide: <strong>{this.state.activeSlide}</strong>
         </p>

src/inner-slider.js

@@ -369,12 +369,13 @@ export class InnerSlider extends React.Component {
   slideHandler = (index, dontAnimate = false) => {
     const {
       asNavFor,
-      currentSlide,
       beforeChange,
       onLazyLoad,
       speed,
       afterChange
     } = this.props;
+    // capture currentslide before state is updated
+    const currentSlide = this.state.currentSlide;
     let { state, nextState } = slideHandler({
       index,
       ...this.props,