first upload all files

Modules/FlashSale/Resources/assets/admin/js/FlashSaleProduct.js

@@ -0,0 +1,43 @@
+export default class {
+    constructor(data) {
+        this.productPanelHtml = this.getProductPanelHtml(data);
+    }
+
+    getProductPanelHtml(data) {
+        data.product = this.normalizeAttributes(data.product);
+
+        let template = _.template($('#flash-sale-product-template').html());
+
+        return $(template(data));
+    }
+
+    normalizeAttributes(product) {
+        if ($.isEmptyObject(product)) {
+            return { id: null, pivot: { campaign_end: null, price: { amount: null }, qty: null } };
+        }
+
+        if (! $.isEmptyObject(FleetCart.errors['flash_sale.products'])) {
+            return {
+                id: product.id,
+                name: product.name,
+                pivot: { campaign_end: product.campaign_end, price: { amount: product.price }, qty: product.qty },
+            };
+        }
+
+        return product;
+    }
+
+    render() {
+        this.attachEventListeners();
+
+        window.admin.dateTimePicker(this.productPanelHtml.find('.datetime-picker'));
+
+        return this.productPanelHtml;
+    }
+
+    attachEventListeners() {
+        this.productPanelHtml.find('.delete-product-panel').on('click', () => {
+            this.productPanelHtml.remove();
+        });
+    }
+}