Feature detection upon checkout

.gitignore

@@ -1,2 +1,5 @@
 bower_components
 build
+env
+client_secrets.json
+*.pyc

src/shop-cart-modal.html

@@ -96,7 +96,7 @@
         <a href="/cart" on-tap="close" id="viewCartAnchor">View Cart</a>
       </shop-button>
       <shop-button class="modal-button">
-        <a href="/checkout" on-tap="close">Checkout</a>
+        <button on-tap="_buyCart" type="button">Checkout</button>
       </shop-button>
     </div>
 
@@ -141,6 +141,11 @@
         this.classList.remove('opened');
       },
 
+      _buyCart: function() {
+        this.fire('buy-cart');
+        this.close();
+      },
+
       _onCancel: function(e) {
         // Don't restore focus when the overlay is closed after a mouse event
         if (e.detail instanceof MouseEvent) {

src/shop-cart.html

@@ -60,7 +60,7 @@ <h1>Your Cart</h1>
         <div class="checkout-box">
           Total: <span class="subtotal">[[_formatTotal(total)]]</span>
           <shop-button responsive>
-            <a href="/checkout">Checkout</a>
+            <button on-tap="_buyCart" type="button">Checkout</button>
           </shop-button>
         </div>
       </div>
@@ -89,7 +89,10 @@ <h1>Your Cart</h1>
           type: Boolean,
           computed: '_computeHasItem(cart.length)'
         }
+      },
 
+      _buyCart: function() {
+        this.fire('buy-cart');
       },
 
       _formatTotal: function(total) {