fix #1299

src/BootstrapTable.js

@@ -501,7 +501,11 @@ class BootstrapTable extends Component {
     });
   }
 
-  handleExpandRow = expanding => {
+  handleExpandRow = (expanding, rowKey, isRowExpanding) => {
+    const { onExpand } = this.props.options;
+    if (onExpand) {
+      onExpand(rowKey, !isRowExpanding);
+    }
     this.setState({ expanding, reset: false }, () => {
       this._adjustHeaderWidth();
     });
@@ -1451,6 +1455,7 @@ BootstrapTable.propTypes = {
     expandRowBgColor: PropTypes.string,
     expandBy: PropTypes.string,
     expanding: PropTypes.array,
+    onExpand: PropTypes.func,
     onlyOneExpanding: PropTypes.bool,
     beforeShowError: PropTypes.func,
     printToolBar: PropTypes.bool
@@ -1598,6 +1603,7 @@ BootstrapTable.defaultProps = {
     expandRowBgColor: undefined,
     expandBy: Const.EXPAND_BY_ROW,
     expanding: [],
+    onExpand: undefined,
     onlyOneExpanding: false,
     beforeShowError: undefined,
     printToolBar: true

src/TableBody.js

@@ -316,15 +316,17 @@ class TableBody extends Component {
       if configure as expanding by column */
       (expandBy === Const.EXPAND_BY_COL && columnIndex < 0) ||
       (expandBy === Const.EXPAND_BY_COL && columns[columnIndex].expandable))) {
-      const rowKey = this.props.data[rowIndex - 1][keyField];
       let expanding = this.props.expanding;
-      if (expanding.indexOf(rowKey) > -1) {
+      const rowKey = this.props.data[rowIndex - 1][keyField];
+      const isRowExpanding = expanding.indexOf(rowKey) > -1;
+
+      if (isRowExpanding) {  // collapse
         expanding = expanding.filter(k => k !== rowKey);
-      } else {
+      } else {  // expand
         if (onlyOneExpanding) expanding = [ rowKey ];
         else expanding.push(rowKey);
       }
-      this.props.onExpand(expanding);
+      this.props.onExpand(expanding, rowKey, isRowExpanding);
     }
   }