fix bug introduced in value change code

interface/src/components/RestComponent.js

@@ -89,7 +89,13 @@ export const restComponent = (endpointUrl, FormComponent) => {
           });
       }
 
-      handleValueChange = name => (event, newValue) => {
+      handleValueChange = name => (event) => {
+        const { data } = this.state;
+        data[name] = event.target.value;
+        this.setState({ data });
+      };
+
+      handleSliderChange = name => (event, newValue) => {
         const { data } = this.state;
         data[name] = newValue;
         this.setState({ data });
@@ -105,6 +111,7 @@ export const restComponent = (endpointUrl, FormComponent) => {
         return <FormComponent
           handleValueChange={this.handleValueChange}
           handleCheckboxChange={this.handleCheckboxChange}
+          handleSliderChange={this.handleSliderChange}
           setData={this.setData}
           saveData={this.saveData}
           loadData={this.loadData}

interface/src/project/DemoController.js

@@ -21,7 +21,7 @@ class DemoController extends Component {
   }
 
   render() {
-    const { data, fetched, errorMessage, saveData, loadData, handleValueChange } = this.props;
+    const { data, fetched, errorMessage, saveData, loadData, handleSliderChange } = this.props;
     return (
       <SectionContent title="Controller" titleGutter>
         <LoadingNotification
@@ -33,7 +33,7 @@ class DemoController extends Component {
               demoSettings={data}
               onReset={loadData}
               onSubmit={saveData}
-              handleValueChange={handleValueChange}
+              handleSliderChange={handleSliderChange}
             />
           }
         />
@@ -53,7 +53,7 @@ const useStyles = makeStyles(theme => ({
 }));
 
 function DemoControllerForm(props) {
-  const { demoSettings, onSubmit, onReset, handleValueChange } = props;
+  const { demoSettings, onSubmit, onReset, handleSliderChange } = props;
   const classes = useStyles();
   return (
     <ValidatorForm onSubmit={onSubmit}>
@@ -67,7 +67,7 @@ function DemoControllerForm(props) {
         valueLabelDisplay="on"
         min={0}
         max={255}
-        onChange={handleValueChange('blink_speed')}
+        onChange={handleSliderChange('blink_speed')}
       />
       <Button variant="contained" color="primary" className={classes.button} type="submit">
         Save