PizzaTalk

The PizzaTalk application is the flagship sample application for Voice Platform. It models an automated dialog for ordering and specifying delivery of a pizza using a variety of VoiceXML features. The PizzaTalk application:

• Demonstrates how to organize a dialog in a series of files.
• Provides a model for an application root document.
• Shows how dynamic content can be generated using Java Server Pages (JSP).
• Demonstrates sophisticated design by using context-specific prompts.
• Shows how to send logs and alarms to the Management Station.

Notes for running PizzaTalk

The initial page URI for the PizzaTalk application is:

http://hostname:8090/PizzaTalk/dialogs/Welcome.vxml

Sample dialogs

The first sample dialog provides a simplest case interaction with the application.

Application	[Nuance earcon] Hi, and thanks for calling PizzaTalk with speech recognition by Nuance. So. . . what size pizza would you like?
Caller	Medium.
Application	And what do you want on it?
Caller	Pepperoni, mushrooms, and green peppers.
Application	You want a medium pizza with pepperoni, mushrooms, and green peppers. Is that right?
Caller	Yes.
Application	Great! Now what’s your phone number?
Caller	605-847-5555.
Application	I heard 605-847-5555. Did I get that right?
Caller	Yes.
Application	Thanks. By the way, we’ve already got your address on file. Now do you want your order to be delivered within the next hour?
Caller	Yes.
Application	Okay. I got a medium pizza with pepperoni, mushrooms, and green peppers to be delivered to 1380 Willow Road. Thanks for calling PizzaTalk. Ciao!

In the next sample dialog, the caller can’t make up his mind about the toppings and wants delivery at a later time.

Application	[Nuance earcon] Hi, and thanks for calling PizzaTalk with speech recognition by Nuance. So. . . what size pizza would you like?
Caller	Medium.
Application	And what do you want on it?
Caller	[no speech].
Application	Sorry. I couldn’t hear you. What do you want on your pizza? Or you can ask, “What are the toppings?”
Caller	What are the toppings?
Application	Okay. Here’s what we’ve got: pepperoni, sausage, mushrooms, anchovies, ground beef, extra cheese, garlic, lotsa garlic, bacon, Canadian bacon, pineapple, chicken, olives, artichoke hearts, green peppers, jalapenos, linguiça, onions, red onions, pastrami, salami, shrimp, spinach, tomatoes, and zucchini. Sorry. I couldn’t hear you. What do you want on your pizza? Or you can ask, “What are the toppings?”
Caller	Pepperoni, mushrooms, and green peppers.
Application	You want a medium pizza with pepperoni, mushrooms, and green peppers. Is that right?
Caller	No.
Application	Would you like to try again?
Caller	Yes.
Application	What should I change: the size, the toppings, or both?
Caller	The toppings.
Application	No problem. What did you want on that?
Caller	Pepperoni, mushrooms, and jalapenos.
Application	You want a medium pizza with pepperoni, mushrooms, and jalapenos. Is that right?
Caller	Yes.
Application	Great! Now what’s your phone number?
Caller	605-847-5555.
Application	I heard 605-847-5555. Did I get that right?
Caller	Yes.
Application	Thanks. By the way, we’ve already got your address on file. Now do you want your order to be delivered within the next hour?
Caller	No.
Application	Okay. Then what time?
Caller	6:30.
Application	That’s 6:30 p.m., correct?
Caller	Yes.
Application	Okay. I got a medium pizza with pepperoni, mushrooms, and jalapenos to be delivered to 1380 Willow Road. Thanks for calling PizzaTalk. Ciao!

The application root document

Looking at the dialog files, you’ll notice that every one includes application="pizza.vxml" in the <vxml> element. Thus pizza.vxml is the application root document, which is loaded whenever the application is entered. The variables, grammars, and handlers defined in it are available to all the documents that call it. The pizza.vxml file itself does the following:

• Sets several VoiceXML properties to override Voice Platform platform default values.
• Declares a variable that defines the path to the prompt files.
• Declares a set of variables that allow the application to store the details of the pizza order (the order variables are PizzaSize, PizzaToppings, PhoneNumber, and DeliveryTime), and initializes the value of each to null.
• Uses <link> elements to specify application-level grammars for any “help,” “repeat,” “cancel,” and “goodbye” universal commands. These <link> elements also specify the page to go to if the “cancel” or “goodbye” grammar is matched.
• Uses <catch> elements to set up global error and help handling by assigning particular values to the entry variable depending on the event. For example, for a nomatch event, entry is set to rej. The value of the entry variable is tested in each dialog so the prompt that is played suits the caller’s situation. (For more detail on the prompts, see Context-specific prompts.)
• Sets up error handling, which includes logging the error and playing a “technical difficulties” prompt.
• Includes a form that re-initializes all the order variables and then directs the application to the Welcome.vxml dialog for cases when a caller says “cancel.”

Basic dialog flow

The following figure shows the basic dialog flow for the application. The voice browser group property sets Welcome.vxml as the initial page of the application. Welcome.vxml and every other file call pizza.vxml as their application root document. Each page links to the next with a <goto next= .../> element.

Each file represents one dialog state and contains one form that contains one field. (The “Get...” files, which collect information, also have a second form that sets the value of the entry variable to “reentry” and returns to the first form when the field is not filled. See Context-specific prompts.) The dialog states where content is generated dynamically are JSP files rather than VXML, so they can use server-side processing to assemble confirmation message.

Context-specific prompts

Careful prompt design makes PizzaTalk sound natural to callers. This is in part accomplished by having several versions of each prompt, depending on how the caller arrived at this point in the dialog. The entry variable tracks how the caller arrived at this point and is used to specify the prompt to play.

The following table lists the possible values of the entry variable and the contexts they describe.

Value	Caller context
init	entering a dialog state the first time
nst	following a noinput event
rej	following a nomatch event
help	following a help event or repeat event
reentry	caller did not confirm the item

For example, there are five versions of the GetPizzaSize prompt, as follows:

Entry value	Prompt
init	So. . . what size pizza would you like?
nst	Sorry, I couldn’t hear what size. Do you want a personal, small, medium, large or extra-large?
rej	I didn’t get that. Do you want a personal, small, medium, large or extra-large?
help	Sure. I need to know what size pizza you want. Just say personal, small, medium, large or extra-large.
reentry	No problem. Tell me what size you want one more time.

Tracking task completion

PizzaTalk provides an example of using the taskbegin and taskend Nuance extensions. The Welcome.vxml page includes the line:

<nuance:taskbegin name="sold_a_pizza" /> 

and the Wrapup.jsp page includes the line:

<nuance:taskend name="sold_a_pizza" cond="true" reason="" />

If a user does not confirm the pizza size and toppings when prompted, the ConfirmSizeAndToppings.jsp page asks, “Would you like to try again?” If the user says no, the application marks this task as unsuccessful as follows:

<nuance:taskend name="sold_a_pizza" cond="false" reason="User did not confirm"/>

For details, see Tracking tasks in your applications.