update demo-ecommerce-example,

03_source/mobile/src/pages/DemoEcommerceExample/data/CartStore.ts

@@ -0,0 +1,18 @@
+import { Store } from 'pullstate';
+
+export const CartStore = new Store({
+  total: 0,
+  product_ids: [],
+});
+
+export const addToCart = (categorySlug, productID) => {
+  CartStore.update((s) => {
+    s.product_ids = [...s.product_ids, `${categorySlug}/${parseInt(productID)}`];
+  });
+};
+
+export const removeFromCart = (productIndex) => {
+  CartStore.update((s) => {
+    s.product_ids.splice(productIndex, 1);
+  });
+};