Extensions

Vocola extensions allow voice commands to call custom code, performing actions not offered by the function library. Extensions might be written to control specific operating system or application features, or to manipulate data. Often you can write a useful extension function with just a few lines of code and use it quickly in a voice command.

Creating extensions is straightforward using Microsoft's Visual Studio development environment, available free as Visual Studio Express. Write extension code using any Microsoft .NET language (such as C#, VB.NET, JavaScript, or C++), and leverage the extensive capabilities of the .NET framework (installed on all modern Windows machines).

Extensions may interact with Vocola using the Vocola API, which offers enough access that the Vocola function library is implemented as a Vocola extension. Browse the function library source code (in the FunctionLibrary\Source installation folder) to get a feel for what extensions can do.

An extension is built as a .NET class library DLL and installed by copying it to the Vocola extensions folder. A single extension DLL may contain several extension classes.

The following sections describe aspects of extension development:

Extension Basics -	Fundamentals of extensions, using a simple example.
Creating Extensions -	Step-by-step instructions for creating and installing an extension.
Using Automation -	How to write an extension which controls an application via its automation interface.
Vocola API -	Available properties and methods for use by extensions.
Function Attributes -	Declarations possibly useful to advanced extension developers.