VoiceXML Review - Columns - Speak & Listen

Volume 3, Issue 2 - March/April 2003

In this monthly column, an industry expert will answer common questions about VoiceXML and related technologies. Readers are encouraged to submit questions about VoiceXML, including development, voice-user interface design, and speech technology in general, or how VoiceXML is being used commercially in the marketplace. If you have a question about VoiceXML, e-mail it to speak.and.listen@voicexmlreview.org and be sure to read future issues of VoiceXML Review for the answer.

Continued from page 2...

Creating the VoiceXML

So far, we've focused on using XSLT to generate our grammars and our JavaScript.

Now that we have these pieces, it should be straightforward to author some VoiceXML that implements our call flow.

I've implemented the Voice Dialer in four VoiceXML documents:

dialer_root.vxml - http://www.voicexmlreview.org/Mar2003/columns/speak_files/dialer_root.vxml - the application root that maintains state about the desired destination.

dialer.vxml - http://www.voicexmlreview.org/Mar2003/columns/speak_files/dialer.vxml - prompts the user for an employee and listens for "departments". Observe how it sources in the employee grammar (emps.srgs) and the employee data (emps.js)

depts.vxml - http://www.voicexmlreview.org/Mar2003/columns/speak_files/depts.vxml - lists the departments. Observe how it sources in the department grammar (depts.srgs) and the department data (depts.js)

connectme.vxml - http://www.voicexmlreview.org/Mar2003/columns/speak_files/connectme.vxml - transfers the caller to the desired number.

Regardless of whether you add, update or delete an employee or a department in the DBMS,
the VoiceXML doesn't have to change. You need only export the data to XML and regenerate the grammars
and .js files by transforming the XML through the appropriate .xslt documents.

Automating the creation of the XML data source documents.

The relevant data in the employee and department table may not change often, but
manually exporting the data isn't a good use of anyone's time.

To automate this task you have a couple of powerful tools at your disposal - the Windows Script Host (WSH) and the Windows Task Scheduler.

We introduced WSH earlier in the column. The Windows Task Scheduler is a service that runs on the Windows Platform and is designed to run any batch file, program, or document at a specified time or interval.

For more information on Windows Task Scheduler, see: "http://msdn.microsoft.com/library/default.asp?url=/library/en-us/taskschd/taskschd/the_task_scheduler_api.asp

By combining the use of WSH and Windows Task Scheduler, you can easily automate the export of data from MS Access. Here's how.

First we'll author a simple script in JScript that programs Microsoft Access to export the data from any table of any Access database (.mdb) to an XML document (.xml).

http://www.voicexmlreview.org/Mar2003/columns/speak_files/mdb2xml.js

The script is simple. First it creates an instance of Microsoft Access using the programmatic identifier (ProgID) "Access.Application". A ProgID is a simple abstraction that allows COM, Microsoft's component technology, to invoke an application or shared library (.dll). The script then instructs access to perform four simple tasks:

Open a .mdb

Export a table as XML

Close the .mdb

Quit

It's that simple. To automate Microsoft Access to perform other tasks, see the Microsoft Access Object Model documentation:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vbaac10/html/acsumAccessObjHierarchy.asp

To use the script, create a text file using your favorite programming editor (e.g. Notepad), and save it to a file with a .js extension, for example, "mdb2xml.js".
Identify the following:

The location of your .mdb (e.g. c:\data\emp.mdb)
The name of the table (e.g. employee)
The location where you'd like to save the exported XML document. (e.g. c:\exports\employee.xml)

Type the following at the command line, adjusting the paths as appropriate:

cscript c:\bin\mdb2xml.js c:\data\emp.mdb employee c:\exports\employee.xml

If the script is successful, your table should be exported to the XML document employee.xml in c:\exports.

Now that you've tested the script, you can program the Windows Task Scheduler to execute the script for you.
Assuming your running Windows XP, to schedule a task using the Windows Task Scheduler, do the following:

From the Start Menu, choose "Control Panel".
Double-click "Scheduled Tasks".
Double-click "Add Scheduled Task". A wizard guides you through the process of creating a new task.
Click "Next".
The wizard will present you with a list of programs. Since WSH (cscript.exe) will not be listed, click Browse...
By default, cscript.exe is located in the system32 subdirectory of your Windows directory (e.g. c:\windows\system32\cscript.exe). Select it.
Choose how frequently you wish to execute the task (daily, weekly, monthly, etc). You'll be given an opportunity to choose a more frequent interval later. Click "Next".
Specify the date and time you wish to first execute the task, and click "Next".
Specify the credentials of the account you wish to use to perform the task, and click "Next".
To specify parameters and to increase the frequency that the task should run, check "Open advanced properties...", and click "Finish".
In the "Run" text box, specify the additional parameters using full paths to the location of the export .js script, the .mdb, the table, and the .xml to export.
To run the task more frequently than once per day, click the "Schedule" tab, and click "Advanced...". Check "Repeat task", and specify the frequency (e.g. Every 1 hour). Click "Ok" to dismiss the "Advanced Schedule Options" dialog.
Click "Ok" to dismiss the Task dialog.

Now that your familiar with the Windows Task Scheduler, you should be able to create tasks to export the department data and to perform all four transformations.

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