Fix id for selected item, return when CostumeCanvas draw fails

src/components/costume-canvas.js

@@ -25,6 +25,9 @@ class CostumeCanvas extends React.Component {
         }
     }
     draw () {
+        if (!this.refs.costumeCanvas) {
+            return;
+        }
         // Draw the costume to the rendered canvas.
         const img = this.img;
         const context = this.refs.costumeCanvas.getContext('2d');

src/components/library.js

@@ -28,8 +28,8 @@ class LibraryComponent extends React.Component {
             return <LibraryItem
                 name={dataItem.name}
                 iconURL={scratchURL}
-                key={'item_' + itemId}
-                selected={this.state.selectedItem == itemId}
+                key={'item_' + id}
+                selected={this.state.selectedItem == id}
                 onSelect={this.onSelect}
                 id={id} />;
         });