VXML

Just as you've seen in previous articles with servlets, JSP pages make it trivial to link between VXML pages.

All you had to do was copy your VXML into a file, add a few directives at the top, and save the file with a . jsp extension.

Begin by creating your VXML in a VXML file, and test it out, just as you would when working with a servlet.

VoiceXML is the name given to the standard for voice-based XML output, although the file format itself is called VXML.

It's easy to take a core servlet that outputs basic VXML and extend it with other servlets, each of which provide custom behavior.

As you've seen so far in this article, sometimes a servlet-generated VXML does not make sense.

The main calendar menu is a simple VXML file that provides the main options as a starting point for the rest of the application.

Once the VXML is online, you're ready to link it to a phone number.

Clearly, it's even easier to turn VXML into a JSP page than it is to embed VXML within a servlet.

Once you get a blank screen, you're ready to actually output the VXML file.

Now you're ready to get into some Java code, and learn about generating VXML dynamically.

If the information is valid, you update the XML diary file and write out a VXML fragment that redirects the user to the main menu.

As it turns out, building dynamic VXML gets rid of some of the formality of voice-based systems, as well.

This simplifies the production of VXML and, especially with a freeform input format, makes the production of the information much easier.

Let's quickly run over what was required to get your VXML to work on a servlet, and then move from there to JSP pages.

Figure 3 shows the resulting screen (scrolled down a bit), with all the different access points to the VXML file.

Now, you can put together a simple search function that will take a search term and output the VXML required to list the results found.

Only after you do all of these steps -- ensuring that your VXML works -- are you ready to even begin thinking about coding Java.

To start, you process a feed and output the VXML to read out the stories to generate the main list of information.

This is just a test to ensure the VXML is available, so don't be concerned if your computer doesn't start speaking to you.

One of the simplest things you can do with servlet-based VXML output is add some awareness of time.

If there are any problems, you can be reasonably sure that you've got Java coding issues to work out, rather than VXML ones.

You can easily embed the text specification into a VXML document by using a CDATA block.

Rather than add all these variables -- no pun intended -- ensure that you start with a working VXML file.

At the end of the diary list, it returns the user back to the main menu VXML file.

The submit tag within VXML passes on the field values to a specified remote application as standard HTTP parameters.

Hence you can produce a simple spoken sentence using the VXML in Listing 2.

In this article, you'll learn about a true middle-of-the-road approach: using JSP pages to output your VXML.

VXML supports different form blocks in a single file that can be used to output all of the different solutions.

It's a voice-recognition VXML file that takes in a favorite instrument and offers some commentary on the caller's choices.

The submit tag within VXML can be used to exchange field information between VXML and scripts that can handle the information.

Write this VXML, save it, upload it to your ISP, and assign a number to it.

Then, you rework your account information page, and create a new VXML file for the account information, account-summary. jsp.

Now browsers (or other code) reading your response can discover the VXML file that was served.

In the same fashion, if the user is using a phone to interact with the system, you may want to add a vxml subelement.

You can create a standardized VXML output that will generate specific elements of fragments according to a pre-defined format.

So far the selections were based on providing information in a static VXML file.

In any case, JDBC makes it simple to connect to a database, and then use results from SQL queries to populate VXML.

You can work with file names and conditionals in your JavaBean classes, keeping your JSP pages free to focus on the VXML of the page itself.

The basic operation of the feed parser and the generation of the VXML is the same as with the Perl examples.

Listing 5 shows the VXML required to send the response information from the variables to the script that will save your appointment.

After the grammar validation, the system executes the element in the rbwelcome. vxml file.

Dial in to this new number and you should hear the prompt from the VXML back in Listing 2. Congratulations!

Before you work on the VXML, you need to examine the blogging interface that will support your connection to the blog.

Rather than having to code grammar for each and every VXML file, you can share a grammar between similar files.

The most obvious application of Java concerning VoiceXML is using a database to feed a dynamic VXML output.

This approach makes it pretty simple to separate your VXML syntax from your application's logic.

You just fetch the feed and generate the output on the fly, rather than create a static VXML file.

This is the simplest and best way to make sure that your VXML has no problems.

You can store your VXML in several different mediums, from a static file to compiled code.

Incidentally, you might produce all of the required output using VXML.

After you've got your VXML working, it's a fairly simple process to move to using servlets.

The resulting VXML (including the surrounding field definitions) outputs the content in Listing 9.

Next, put your VXML file somewhere publicly accessible.

You can react to users' choices by dynamically generating VXML as needed.

The first step in getting your VXML ready for use is to prototype the file.

With those considerations aside, let's examine the VXML to accept a new appointment entry.

In these simple cases, stick with using static VXML files.

In fact, you'll notice that many of the example VXML files are holdovers from the first two articles in this series.

In your VXML the block is located within the filled section (see Listing 10).

Listing 10 and Listing 11, respectively, show sample transformation XSL style sheets for XML to WML and XML to VXML.

Listing 1 show the basic format for a VXML file.

When the variable is filled, the filled block in the VXML is parsed.

Next, look at the VXML source that you'll use to accept the input.

I introduced the process of developing VXML, and then showed you how to integrate Java technology into that process.

For telephone process, mainly use the VXML to complete the development process.

And technical standards such as VXML, which provides a standard way to program voice dialogues, have made things easier too.

Listing 5 shows the sample VXML generated in the process.

The result is that you can very quickly output a VXML form to accept input from a user.

You can see the VXML to generate this description in Listing 4.

For example, it's common to run into file-access problems or typos in the VXML file path.

Of course, more often that not, you'll link to another JSP page that in turn outputs VXML of its own

Generate a VXML file that outputs a list of the accepted phrases, and then a list of the accepted categories

The VXML uses the input method to submit the category and phrase information to the servlet

Differences between callers and VXML generators

Create VXML grammar that supports a wide range of input

VXML: Voice eXtensible Markup Language

Create a generic class for outputting VXML form elements

Submit the request to the blog and report back through VXML

The Commercial Navigation System Based on VXML Speech Information