Step 8: Send a command to display items in the cart

When the user gives a command, we want to display the ordered items in the cart on the web page. To do this, we will send a command from the dialog script to the app and, once the command is received, have the app perform the necessary activity.

1. We will start with the dialog script. First, let’s add the number variable to our command. If the user’s input contains the number and it is caught with the NUMBER slot, number is set to a numeric representation of the item quantity — p.NUMBER.number; otherwise, it is set to 1.

   Dialog script

   const itemList = "pepperoni_|margherita_|burrito_|burger_|taco_|apple pie_";
   
   intent(`(I want|I will take|Add|) (a|an|) $(ITEM ${itemList}), (please|)`,
          `(I want|I will take|Add|) $(NUMBER) $(ITEM ${itemList}), (please|)`, p => {
       p.play(`Adding ${p.ITEM.value} for you`, 'Sure', 'Here you go');
       // Getting the number of ordered items
       let number = p.NUMBER ? p.NUMBER.number : 1;
   });
   

2. To send a command from the dialog script, add another p.play() function and specify a JSON object in it. In our case, the object contains the command name — updateOrder, item name and quantity:

   Dialog script

   const itemList = "pepperoni_|margherita_|burrito_|burger_|taco_|apple pie_";
   
   intent(`(I want|I will take|Add|) (a|an|) $(ITEM ${itemList}), (please|)`,
          `(I want|I will take|Add|) $(NUMBER) $(ITEM ${itemList}), (please|)`, p => {
       p.play(`Adding ${p.ITEM.value} for you`, 'Sure', 'Here you go');
       let number = p.NUMBER ? p.NUMBER.number : 1;
       // Sending the command to the app
       p.play({command: 'updateOrder', item: p.ITEM.value, quantity: number});
   });
   

   Try the command in the Debugging Chat. Notice that together with the answer, Alan AI now sends the command we have added.

3. We need to handle this command on the app side. To do this, let’s add the order object, changeOrder() and updateCart() functions to our web page:

   HTML file

   <script>
       // Setting the order
       let order = {};
   
       // Showing the order on the page
       function updateCart() {
           let html = "";
           for (let key in order) {
               html += `<tr><td>${key}</td><td>${order[key]}</td>`;
           }
           html = `<table border="0">${html}</table>`;
           document.getElementById("order").innerHTML = html;
       }
   
       // Changing the number of items in the order
       function changeOrder(item, quantity) {
           let number = (order[item] ? order[item] : 0) + quantity;
           order[item] = number;
           updateCart();
       }
   </script>
   

4. Finally, we will make sure the changeOrder() function is called when the user gives the command. In the Alan AI button code block in the app, find the onCommand handler and update it so that the changeOrder() function is invoked once the app receives the updateOrder command. To the function, we will pass the item name and quantity:

   HTML file

   <script>
       var alanBtnInstance = alanBtn({
           key: "e2fecaef4cb07cbe7d43485dbc3cb44a2e956eca572e1d8b807a3e2338fdd0dc/stage",
           // Handling the updateOrder command
           onCommand: function (commandData) {
               if (commandData.command == "updateOrder") {
                    changeOrder(commandData.item, commandData.quantity);
               }
           },
           rootEl: document.getElementById("alan-btn"),
       });
   </script>
   

   Web page source | Dialog script

Here is how it works: when the user makes an order, the AI assistant plays a response and sends the updateOrder command to the app. With this command, it sends the item name and quantity. On the app side, the changeOrder() function is called that updates the order object and shows the current order on the page with updateCart().

You can test it: in the app, click the Alan AI button and try ordering food with voice.