Building Transforms for XML
The MapForce graphical editor is a simple yet extremely powerful environment in which to transform documents. Shown in Figure 2 with the mapping exercise from the tutorial, it uses a standard drag-and-drop interface to build the transformation logic. When working with XML, source and target schemas are identified and represented as side-by-side tree structures. Source nodes may be dragged to the relevant target nodes. If working with higher-level-containing structures, MapForce will automatically map child nodes based on a set of configurable criteria. If the transformation method is XSLT, XSLT2, or XQuery, a third tab in the editor is present that contains the relevant source code. As development progresses, MapForce updates the Output tab with the results of the transformation.

As mentioned previously, MapForce supports the latest specifications of XSLT and XQuery, as well as providing the ability to generate code in Java, C#, or C++. At any time during development, the method of transformation may be changed to any of the other supported methods with the simple click of a button. With each method, the output and relevant source code tabs (if visible) are updated in real time.

Working with Databases
Out of the box, MapForce supports Microsoft Access, Microsoft SQL Server, Oracle, MySQL, Sybase, and IBM DB2 natively, along with any other ADO- and ODBC-compatible database. Generally speaking, databases are represented as simple XML documents, with each table acting as a container node for its columns. Mapping rules are defined in the same way as XML transformations with the exception that only Java, C#, and C++ transformation methods are supported.

Other Data Sources
This new version of MapForce provides support for EDI documents and flat files (delimited and fixed width). EDI support includes the UN/EDIFACT directory 0.4B and version 5012 of the ANSI X12 specification.

The flat file definition process is similar to that of Microsoft Excel import utility. Developers select the type of file - fixed or delimited, then proceed by defining the data types and other details of the data to be imported. An option to use the first row of the file as the field names is also available. When completed and imported, the flat file appears as any other transformation source or target in the MapForce mapping window.

StyleVision
StyleVision, as its name implies, is a graphical stylesheet editor. The tool supports XSLT and XSL:FO transformations to HTML, PDF, RTF/Microsoft Word, and Altova's Authentic formats. Like its suite companions, it also provides standard support for XSLT 2.0 and XPath 2.0. Similar to MapForce, the output of this tool is XSLT. However the primary purpose of the XSLT in this case is for presentation and user interaction, instead of data exchange and integration.

Working with Stylesheets
As with MapForce, stylesheets are built directly from the schema or DTD that defines the structure of a document, or directly from database tables. Figure 3 illustrates a simple database stylesheet for a custom issue-tracking system.

The left side of the screen represents the schema of the database that supports the issue-tracking system. The right side of the screen is the graphical structure of the output. Along the bottom are the various output options for rendering the stylesheet.

As seen in the figure, content may be arranged and formatted in any layout supported by HTML. For this example, content will be created for the Authentic Editor - Altova's graphical environment for editing XML content. Since this stylesheet is backed by a database, any element may be represented as an editable field. In the Authentic Editor, changes to the field are then stored back into the database (note: Authentic is the only output option that supports database updates). This functionality provides a fast and easy mechanism to create and deploy simple database applications.

Summary
As XML development grows in complexity and capability, effective tools will always be required to produce high-quality applications. Altova's suite of products is not only effective, but extremely powerful and useful as well. It addresses XML development, data transformation and integration, Web services, and presentation, among a number of other functions. XMLSpy, along with its siblings in the suite, shines, and they are worthy of any XML development effort.