Accessing Other Object Models

Although most of the programming done with Outlook forms is likely to involve the Outlook object model, there may be times when you want to access data from some other application or draw on some system service provided by a particular object model. The VBScript CreateObject function is used for this purpose to access the object model of some other application, while the VBScript GetObject function is the only means available to get a reference to an existing instance of an applicationthat is, to a running application. (For the syntax of both functions, see their entries in Chapter 10.)

The GetObject function exists solely within VBScript, and is not implemented as a method of the Outlook Application object.

As Table 6-15 shows, you can instantiate objects like the following using these methods:

ActiveX Data Objects (ADO)

ADO is a data access technology that offers a uniform methodology for accessing data regardless of location or format. ADO has a relatively "flat" object model, and many objects (like the Recordset object or the Connection object) can be instantiated independently of one another.

Data Access Objects (DAO)

DAO is a data access technology intended primarily for use with Access databases. Its top-level object is named DBEngine.

The Dictionary object

A part of the Scripting Runtime Library, theDictionary object provides high-performance access to data sets that have identifiable keys.

The Excel Application object

The Excel object model is useful for extracting data from spreadsheets or for manipulating charts. Its top-level object is the Application object.

The FileSystemObject object

A part of the Scripting Runtime Library, the FileSystemObject provides access to the local filesystem.

The Word Application object

The Word object model makes it easy to manipulate Word .doc files as well as Rich Text Format (.rtf ) files. Its top-level object is the Application object.

Table 6-15. Some object models and their programmatic identifiers

Object	ProgID	Description
Connection	ADODB.Connection	An ADO database connection
DBEngine	DAO.DBEngine	The DAO object model, primarily for Access databases
Dictionary	Scripting.Dictionary	A high-performance alternative to arrays and collections for keyed data
Excel	Excel.Application	The Microsoft Excel application, for manipulating spreadsheets and charts
FileSystemObject	Scripting.FileSystemObject	Represents the local filesystem
Recordset	ADODB.Recordset	An ADO recordset
Word	Word.Application	The Microsoft Word application for manipulating documents